* [PATCH v1 1/4] KVM: stats: Support linear and logarithmic histogram statistics
@ 2021-07-06 18:03 ` Jing Zhang
0 siblings, 0 replies; 22+ messages in thread
From: Jing Zhang @ 2021-07-06 18:03 UTC (permalink / raw)
To: KVM, KVMPPC, Paolo Bonzini, Sean Christopherson, Jim Mattson,
Peter Shier, Oliver Upton, David Rientjes, David Matlack
Cc: Jing Zhang
Add new types of KVM stats, linear and logarithmic histogram.
Histogram are very useful for observing the value distribution
of time or size related stats.
Signed-off-by: Jing Zhang <jingzhangos@google.com>
---
arch/arm64/kvm/guest.c | 4 ---
arch/mips/kvm/mips.c | 4 ---
arch/powerpc/kvm/book3s.c | 4 ---
arch/powerpc/kvm/booke.c | 4 ---
arch/s390/kvm/kvm-s390.c | 4 ---
arch/x86/kvm/x86.c | 4 ---
include/linux/kvm_host.h | 53 ++++++++++++++++++++++++++++-----------
include/linux/kvm_types.h | 16 ++++++++++++
include/uapi/linux/kvm.h | 11 +++++---
virt/kvm/binary_stats.c | 36 ++++++++++++++++++++++++++
10 files changed, 98 insertions(+), 42 deletions(-)
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 1512a8007a78..cb44d8756fa7 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -31,8 +31,6 @@
const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
KVM_GENERIC_VM_STATS()
};
-static_assert(ARRAY_SIZE(kvm_vm_stats_desc) =
- sizeof(struct kvm_vm_stat) / sizeof(u64));
const struct kvm_stats_header kvm_vm_stats_header = {
.name_size = KVM_STATS_NAME_SIZE,
@@ -52,8 +50,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
STATS_DESC_COUNTER(VCPU, mmio_exit_kernel),
STATS_DESC_COUNTER(VCPU, exits)
};
-static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) =
- sizeof(struct kvm_vcpu_stat) / sizeof(u64));
const struct kvm_stats_header kvm_vcpu_stats_header = {
.name_size = KVM_STATS_NAME_SIZE,
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index af9dd029a4e1..75c6f264c626 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -41,8 +41,6 @@
const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
KVM_GENERIC_VM_STATS()
};
-static_assert(ARRAY_SIZE(kvm_vm_stats_desc) =
- sizeof(struct kvm_vm_stat) / sizeof(u64));
const struct kvm_stats_header kvm_vm_stats_header = {
.name_size = KVM_STATS_NAME_SIZE,
@@ -85,8 +83,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
STATS_DESC_COUNTER(VCPU, vz_cpucfg_exits),
#endif
};
-static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) =
- sizeof(struct kvm_vcpu_stat) / sizeof(u64));
const struct kvm_stats_header kvm_vcpu_stats_header = {
.name_size = KVM_STATS_NAME_SIZE,
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 79833f78d1da..5cc6e90095b0 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -43,8 +43,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
STATS_DESC_ICOUNTER(VM, num_2M_pages),
STATS_DESC_ICOUNTER(VM, num_1G_pages)
};
-static_assert(ARRAY_SIZE(kvm_vm_stats_desc) =
- sizeof(struct kvm_vm_stat) / sizeof(u64));
const struct kvm_stats_header kvm_vm_stats_header = {
.name_size = KVM_STATS_NAME_SIZE,
@@ -88,8 +86,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
STATS_DESC_COUNTER(VCPU, pthru_host),
STATS_DESC_COUNTER(VCPU, pthru_bad_aff)
};
-static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) =
- sizeof(struct kvm_vcpu_stat) / sizeof(u64));
const struct kvm_stats_header kvm_vcpu_stats_header = {
.name_size = KVM_STATS_NAME_SIZE,
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 551b30d84aee..5ed6c235e059 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -41,8 +41,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
STATS_DESC_ICOUNTER(VM, num_2M_pages),
STATS_DESC_ICOUNTER(VM, num_1G_pages)
};
-static_assert(ARRAY_SIZE(kvm_vm_stats_desc) =
- sizeof(struct kvm_vm_stat) / sizeof(u64));
const struct kvm_stats_header kvm_vm_stats_header = {
.name_size = KVM_STATS_NAME_SIZE,
@@ -79,8 +77,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
STATS_DESC_COUNTER(VCPU, pthru_host),
STATS_DESC_COUNTER(VCPU, pthru_bad_aff)
};
-static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) =
- sizeof(struct kvm_vcpu_stat) / sizeof(u64));
const struct kvm_stats_header kvm_vcpu_stats_header = {
.name_size = KVM_STATS_NAME_SIZE,
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 1695f0ced5ba..7610d33d319b 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -66,8 +66,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
STATS_DESC_COUNTER(VM, inject_service_signal),
STATS_DESC_COUNTER(VM, inject_virtio)
};
-static_assert(ARRAY_SIZE(kvm_vm_stats_desc) =
- sizeof(struct kvm_vm_stat) / sizeof(u64));
const struct kvm_stats_header kvm_vm_stats_header = {
.name_size = KVM_STATS_NAME_SIZE,
@@ -174,8 +172,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
STATS_DESC_COUNTER(VCPU, diagnose_other),
STATS_DESC_COUNTER(VCPU, pfault_sync)
};
-static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) =
- sizeof(struct kvm_vcpu_stat) / sizeof(u64));
const struct kvm_stats_header kvm_vcpu_stats_header = {
.name_size = KVM_STATS_NAME_SIZE,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 8166ad113fb2..b94a80ad5b8d 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -239,8 +239,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
STATS_DESC_ICOUNTER(VM, nx_lpage_splits),
STATS_DESC_PCOUNTER(VM, max_mmu_page_hash_collisions)
};
-static_assert(ARRAY_SIZE(kvm_vm_stats_desc) =
- sizeof(struct kvm_vm_stat) / sizeof(u64));
const struct kvm_stats_header kvm_vm_stats_header = {
.name_size = KVM_STATS_NAME_SIZE,
@@ -280,8 +278,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
STATS_DESC_COUNTER(VCPU, directed_yield_successful),
STATS_DESC_ICOUNTER(VCPU, guest_mode)
};
-static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) =
- sizeof(struct kvm_vcpu_stat) / sizeof(u64));
const struct kvm_stats_header kvm_vcpu_stats_header = {
.name_size = KVM_STATS_NAME_SIZE,
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index ae7735b490b4..356af173114d 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1273,56 +1273,66 @@ struct _kvm_stats_desc {
char name[KVM_STATS_NAME_SIZE];
};
-#define STATS_DESC_COMMON(type, unit, base, exp) \
+#define STATS_DESC_COMMON(type, unit, base, exp, sz, param) \
.flags = type | unit | base | \
BUILD_BUG_ON_ZERO(type & ~KVM_STATS_TYPE_MASK) | \
BUILD_BUG_ON_ZERO(unit & ~KVM_STATS_UNIT_MASK) | \
BUILD_BUG_ON_ZERO(base & ~KVM_STATS_BASE_MASK), \
.exponent = exp, \
- .size = 1
+ .size = sz, \
+ .hist_param = param
-#define VM_GENERIC_STATS_DESC(stat, type, unit, base, exp) \
+#define VM_GENERIC_STATS_DESC(stat, type, unit, base, exp, sz, param) \
{ \
{ \
- STATS_DESC_COMMON(type, unit, base, exp), \
+ STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
.offset = offsetof(struct kvm_vm_stat, generic.stat) \
}, \
.name = #stat, \
}
-#define VCPU_GENERIC_STATS_DESC(stat, type, unit, base, exp) \
+#define VCPU_GENERIC_STATS_DESC(stat, type, unit, base, exp, sz, param) \
{ \
{ \
- STATS_DESC_COMMON(type, unit, base, exp), \
+ STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
.offset = offsetof(struct kvm_vcpu_stat, generic.stat) \
}, \
.name = #stat, \
}
-#define VM_STATS_DESC(stat, type, unit, base, exp) \
+#define VM_STATS_DESC(stat, type, unit, base, exp, sz, param) \
{ \
{ \
- STATS_DESC_COMMON(type, unit, base, exp), \
+ STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
.offset = offsetof(struct kvm_vm_stat, stat) \
}, \
.name = #stat, \
}
-#define VCPU_STATS_DESC(stat, type, unit, base, exp) \
+#define VCPU_STATS_DESC(stat, type, unit, base, exp, sz, param) \
{ \
{ \
- STATS_DESC_COMMON(type, unit, base, exp), \
+ STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
.offset = offsetof(struct kvm_vcpu_stat, stat) \
}, \
.name = #stat, \
}
/* SCOPE: VM, VM_GENERIC, VCPU, VCPU_GENERIC */
-#define STATS_DESC(SCOPE, stat, type, unit, base, exp) \
- SCOPE##_STATS_DESC(stat, type, unit, base, exp)
+#define STATS_DESC(SCOPE, stat, type, unit, base, exp, sz, param) \
+ SCOPE##_STATS_DESC(stat, type, unit, base, exp, sz, param)
#define STATS_DESC_CUMULATIVE(SCOPE, name, unit, base, exponent) \
- STATS_DESC(SCOPE, name, KVM_STATS_TYPE_CUMULATIVE, unit, base, exponent)
+ STATS_DESC(SCOPE, name, KVM_STATS_TYPE_CUMULATIVE, \
+ unit, base, exponent, 1, 0)
#define STATS_DESC_INSTANT(SCOPE, name, unit, base, exponent) \
- STATS_DESC(SCOPE, name, KVM_STATS_TYPE_INSTANT, unit, base, exponent)
+ STATS_DESC(SCOPE, name, KVM_STATS_TYPE_INSTANT, \
+ unit, base, exponent, 1, 0)
#define STATS_DESC_PEAK(SCOPE, name, unit, base, exponent) \
- STATS_DESC(SCOPE, name, KVM_STATS_TYPE_PEAK, unit, base, exponent)
+ STATS_DESC(SCOPE, name, KVM_STATS_TYPE_PEAK, \
+ unit, base, exponent, 1, 0)
+#define STATS_DESC_LINEAR_HIST(SCOPE, name, unit, base, exponent, sz, param) \
+ STATS_DESC(SCOPE, name, KVM_STATS_TYPE_LINEAR_HIST, \
+ unit, base, exponent, sz, param)
+#define STATS_DESC_LOG_HIST(SCOPE, name, unit, base, exponent, sz, param) \
+ STATS_DESC(SCOPE, name, KVM_STATS_TYPE_LOG_HIST, \
+ unit, base, exponent, sz, param)
/* Cumulative counter, read/write */
#define STATS_DESC_COUNTER(SCOPE, name) \
@@ -1341,6 +1351,14 @@ struct _kvm_stats_desc {
#define STATS_DESC_TIME_NSEC(SCOPE, name) \
STATS_DESC_CUMULATIVE(SCOPE, name, KVM_STATS_UNIT_SECONDS, \
KVM_STATS_BASE_POW10, -9)
+/* Linear histogram for time in nanosecond */
+#define STATS_DESC_LINHIST_TIME_NSEC(SCOPE, name, sz, bucket_size) \
+ STATS_DESC_LINEAR_HIST(SCOPE, name, KVM_STATS_UNIT_SECONDS, \
+ KVM_STATS_BASE_POW10, -9, sz, bucket_size)
+/* Logarithmic histogram for time in nanosecond */
+#define STATS_DESC_LOGHIST_TIME_NSEC(SCOPE, name, sz) \
+ STATS_DESC_LOG_HIST(SCOPE, name, KVM_STATS_UNIT_SECONDS, \
+ KVM_STATS_BASE_POW10, -9, sz, LOGHIST_BASE_2)
#define KVM_GENERIC_VM_STATS() \
STATS_DESC_COUNTER(VM_GENERIC, remote_tlb_flush)
@@ -1354,10 +1372,15 @@ struct _kvm_stats_desc {
STATS_DESC_TIME_NSEC(VCPU_GENERIC, halt_poll_fail_ns)
extern struct dentry *kvm_debugfs_dir;
+
ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header,
const struct _kvm_stats_desc *desc,
void *stats, size_t size_stats,
char __user *user_buffer, size_t size, loff_t *offset);
+void kvm_stats_linear_hist_update(u64 *data, size_t size,
+ u64 value, size_t bucket_size);
+void kvm_stats_log_hist_update(u64 *data, size_t size, u64 value);
+
extern const struct kvm_stats_header kvm_vm_stats_header;
extern const struct _kvm_stats_desc kvm_vm_stats_desc[];
extern const struct kvm_stats_header kvm_vcpu_stats_header;
diff --git a/include/linux/kvm_types.h b/include/linux/kvm_types.h
index ed6a985c5680..cc88cd676775 100644
--- a/include/linux/kvm_types.h
+++ b/include/linux/kvm_types.h
@@ -76,6 +76,22 @@ struct kvm_mmu_memory_cache {
};
#endif
+/* Constants used for histogram stats */
+#define LINHIST_SIZE_SMALL 10
+#define LINHIST_SIZE_MEDIUM 20
+#define LINHIST_SIZE_LARGE 50
+#define LINHIST_SIZE_XLARGE 100
+#define LINHIST_BUCKET_SIZE_SMALL 10
+#define LINHIST_BUCKET_SIZE_MEDIUM 100
+#define LINHIST_BUCKET_SIZE_LARGE 1000
+#define LINHIST_BUCKET_SIZE_XLARGE 10000
+
+#define LOGHIST_SIZE_SMALL 8
+#define LOGHIST_SIZE_MEDIUM 16
+#define LOGHIST_SIZE_LARGE 32
+#define LOGHIST_SIZE_XLARGE 64
+#define LOGHIST_BASE_2 2
+
struct kvm_vm_stat_generic {
u64 remote_tlb_flush;
};
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 68c9e6d8bbda..ff34a471d9ef 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1963,7 +1963,9 @@ struct kvm_stats_header {
#define KVM_STATS_TYPE_CUMULATIVE (0x0 << KVM_STATS_TYPE_SHIFT)
#define KVM_STATS_TYPE_INSTANT (0x1 << KVM_STATS_TYPE_SHIFT)
#define KVM_STATS_TYPE_PEAK (0x2 << KVM_STATS_TYPE_SHIFT)
-#define KVM_STATS_TYPE_MAX KVM_STATS_TYPE_PEAK
+#define KVM_STATS_TYPE_LINEAR_HIST (0x3 << KVM_STATS_TYPE_SHIFT)
+#define KVM_STATS_TYPE_LOG_HIST (0x4 << KVM_STATS_TYPE_SHIFT)
+#define KVM_STATS_TYPE_MAX KVM_STATS_TYPE_LOG_HIST
#define KVM_STATS_UNIT_SHIFT 4
#define KVM_STATS_UNIT_MASK (0xF << KVM_STATS_UNIT_SHIFT)
@@ -1987,7 +1989,10 @@ struct kvm_stats_header {
* Every data item is of type __u64.
* @offset: The offset of the stats to the start of stat structure in
* struture kvm or kvm_vcpu.
- * @unused: Unused field for future usage. Always 0 for now.
+ * @hist_param: A parameter value used for histogram stats. For linear
+ * histogram stats, it indicates the size of the bucket;
+ * For logarithmic histogram stats, it indicates the base
+ * of the logarithm. Only base of 2 is supported.
* @name: The name string for the stats. Its size is indicated by the
* &kvm_stats_header->name_size.
*/
@@ -1996,7 +2001,7 @@ struct kvm_stats_desc {
__s16 exponent;
__u16 size;
__u32 offset;
- __u32 unused;
+ __u32 hist_param;
char name[];
};
diff --git a/virt/kvm/binary_stats.c b/virt/kvm/binary_stats.c
index e609d428811a..6eead6979a7f 100644
--- a/virt/kvm/binary_stats.c
+++ b/virt/kvm/binary_stats.c
@@ -144,3 +144,39 @@ ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header,
*offset = pos;
return len;
}
+
+/**
+ * kvm_stats_linear_hist_update() - Update bucket value for linear histogram
+ * statistics data.
+ *
+ * @data: start address of the stats data
+ * @size: the number of bucket of the stats data
+ * @value: the new value used to update the linear histogram's bucket
+ * @bucket_size: the size (width) of a bucket
+ */
+void kvm_stats_linear_hist_update(u64 *data, size_t size,
+ u64 value, size_t bucket_size)
+{
+ size_t index = value / bucket_size;
+
+ if (index >= size)
+ index = size - 1;
+ ++data[index];
+}
+
+/**
+ * kvm_stats_log_hist_update() - Update bucket value for logarithmic histogram
+ * statistics data.
+ *
+ * @data: start address of the stats data
+ * @size: the number of bucket of the stats data
+ * @value: the new value used to update the logarithmic histogram's bucket
+ */
+void kvm_stats_log_hist_update(u64 *data, size_t size, u64 value)
+{
+ size_t index = fls64(value);
+
+ if (index >= size)
+ index = size - 1;
+ ++data[index];
+}
--
2.32.0.93.g670b81a890-goog
^ permalink raw reply related [flat|nested] 22+ messages in thread
* Re: [PATCH v1 1/4] KVM: stats: Support linear and logarithmic histogram statistics
2021-07-06 18:03 ` Jing Zhang
@ 2021-07-08 21:01 ` David Matlack
-1 siblings, 0 replies; 22+ messages in thread
From: David Matlack @ 2021-07-08 21:01 UTC (permalink / raw)
To: Jing Zhang
Cc: KVM, KVMPPC, Paolo Bonzini, Sean Christopherson, Jim Mattson,
Peter Shier, Oliver Upton, David Rientjes
On Tue, Jul 06, 2021 at 06:03:47PM +0000, Jing Zhang wrote:
> Add new types of KVM stats, linear and logarithmic histogram.
> Histogram are very useful for observing the value distribution
> of time or size related stats.
>
> Signed-off-by: Jing Zhang <jingzhangos@google.com>
> ---
> arch/arm64/kvm/guest.c | 4 ---
> arch/mips/kvm/mips.c | 4 ---
> arch/powerpc/kvm/book3s.c | 4 ---
> arch/powerpc/kvm/booke.c | 4 ---
> arch/s390/kvm/kvm-s390.c | 4 ---
> arch/x86/kvm/x86.c | 4 ---
> include/linux/kvm_host.h | 53 ++++++++++++++++++++++++++++-----------
> include/linux/kvm_types.h | 16 ++++++++++++
> include/uapi/linux/kvm.h | 11 +++++---
> virt/kvm/binary_stats.c | 36 ++++++++++++++++++++++++++
> 10 files changed, 98 insertions(+), 42 deletions(-)
>
> diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
> index 1512a8007a78..cb44d8756fa7 100644
> --- a/arch/arm64/kvm/guest.c
> +++ b/arch/arm64/kvm/guest.c
> @@ -31,8 +31,6 @@
> const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> KVM_GENERIC_VM_STATS()
> };
> -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
> - sizeof(struct kvm_vm_stat) / sizeof(u64));
>
> const struct kvm_stats_header kvm_vm_stats_header = {
> .name_size = KVM_STATS_NAME_SIZE,
> @@ -52,8 +50,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> STATS_DESC_COUNTER(VCPU, mmio_exit_kernel),
> STATS_DESC_COUNTER(VCPU, exits)
> };
> -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) ==
> - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
>
> const struct kvm_stats_header kvm_vcpu_stats_header = {
> .name_size = KVM_STATS_NAME_SIZE,
> diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
> index af9dd029a4e1..75c6f264c626 100644
> --- a/arch/mips/kvm/mips.c
> +++ b/arch/mips/kvm/mips.c
> @@ -41,8 +41,6 @@
> const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> KVM_GENERIC_VM_STATS()
> };
> -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
> - sizeof(struct kvm_vm_stat) / sizeof(u64));
>
> const struct kvm_stats_header kvm_vm_stats_header = {
> .name_size = KVM_STATS_NAME_SIZE,
> @@ -85,8 +83,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> STATS_DESC_COUNTER(VCPU, vz_cpucfg_exits),
> #endif
> };
> -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) ==
> - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
>
> const struct kvm_stats_header kvm_vcpu_stats_header = {
> .name_size = KVM_STATS_NAME_SIZE,
> diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
> index 79833f78d1da..5cc6e90095b0 100644
> --- a/arch/powerpc/kvm/book3s.c
> +++ b/arch/powerpc/kvm/book3s.c
> @@ -43,8 +43,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> STATS_DESC_ICOUNTER(VM, num_2M_pages),
> STATS_DESC_ICOUNTER(VM, num_1G_pages)
> };
> -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
> - sizeof(struct kvm_vm_stat) / sizeof(u64));
>
> const struct kvm_stats_header kvm_vm_stats_header = {
> .name_size = KVM_STATS_NAME_SIZE,
> @@ -88,8 +86,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> STATS_DESC_COUNTER(VCPU, pthru_host),
> STATS_DESC_COUNTER(VCPU, pthru_bad_aff)
> };
> -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) ==
> - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
>
> const struct kvm_stats_header kvm_vcpu_stats_header = {
> .name_size = KVM_STATS_NAME_SIZE,
> diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
> index 551b30d84aee..5ed6c235e059 100644
> --- a/arch/powerpc/kvm/booke.c
> +++ b/arch/powerpc/kvm/booke.c
> @@ -41,8 +41,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> STATS_DESC_ICOUNTER(VM, num_2M_pages),
> STATS_DESC_ICOUNTER(VM, num_1G_pages)
> };
> -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
> - sizeof(struct kvm_vm_stat) / sizeof(u64));
>
> const struct kvm_stats_header kvm_vm_stats_header = {
> .name_size = KVM_STATS_NAME_SIZE,
> @@ -79,8 +77,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> STATS_DESC_COUNTER(VCPU, pthru_host),
> STATS_DESC_COUNTER(VCPU, pthru_bad_aff)
> };
> -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) ==
> - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
>
> const struct kvm_stats_header kvm_vcpu_stats_header = {
> .name_size = KVM_STATS_NAME_SIZE,
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index 1695f0ced5ba..7610d33d319b 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -66,8 +66,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> STATS_DESC_COUNTER(VM, inject_service_signal),
> STATS_DESC_COUNTER(VM, inject_virtio)
> };
> -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
> - sizeof(struct kvm_vm_stat) / sizeof(u64));
>
> const struct kvm_stats_header kvm_vm_stats_header = {
> .name_size = KVM_STATS_NAME_SIZE,
> @@ -174,8 +172,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> STATS_DESC_COUNTER(VCPU, diagnose_other),
> STATS_DESC_COUNTER(VCPU, pfault_sync)
> };
> -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) ==
> - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
>
> const struct kvm_stats_header kvm_vcpu_stats_header = {
> .name_size = KVM_STATS_NAME_SIZE,
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 8166ad113fb2..b94a80ad5b8d 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -239,8 +239,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> STATS_DESC_ICOUNTER(VM, nx_lpage_splits),
> STATS_DESC_PCOUNTER(VM, max_mmu_page_hash_collisions)
> };
> -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
> - sizeof(struct kvm_vm_stat) / sizeof(u64));
>
> const struct kvm_stats_header kvm_vm_stats_header = {
> .name_size = KVM_STATS_NAME_SIZE,
> @@ -280,8 +278,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> STATS_DESC_COUNTER(VCPU, directed_yield_successful),
> STATS_DESC_ICOUNTER(VCPU, guest_mode)
> };
> -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) ==
> - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
>
> const struct kvm_stats_header kvm_vcpu_stats_header = {
> .name_size = KVM_STATS_NAME_SIZE,
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index ae7735b490b4..356af173114d 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -1273,56 +1273,66 @@ struct _kvm_stats_desc {
> char name[KVM_STATS_NAME_SIZE];
> };
>
> -#define STATS_DESC_COMMON(type, unit, base, exp) \
> +#define STATS_DESC_COMMON(type, unit, base, exp, sz, param) \
> .flags = type | unit | base | \
> BUILD_BUG_ON_ZERO(type & ~KVM_STATS_TYPE_MASK) | \
> BUILD_BUG_ON_ZERO(unit & ~KVM_STATS_UNIT_MASK) | \
> BUILD_BUG_ON_ZERO(base & ~KVM_STATS_BASE_MASK), \
> .exponent = exp, \
> - .size = 1
> + .size = sz, \
> + .hist_param = param
>
> -#define VM_GENERIC_STATS_DESC(stat, type, unit, base, exp) \
> +#define VM_GENERIC_STATS_DESC(stat, type, unit, base, exp, sz, param) \
> { \
> { \
> - STATS_DESC_COMMON(type, unit, base, exp), \
> + STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
> .offset = offsetof(struct kvm_vm_stat, generic.stat) \
> }, \
> .name = #stat, \
> }
> -#define VCPU_GENERIC_STATS_DESC(stat, type, unit, base, exp) \
> +#define VCPU_GENERIC_STATS_DESC(stat, type, unit, base, exp, sz, param) \
> { \
> { \
> - STATS_DESC_COMMON(type, unit, base, exp), \
> + STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
> .offset = offsetof(struct kvm_vcpu_stat, generic.stat) \
> }, \
> .name = #stat, \
> }
> -#define VM_STATS_DESC(stat, type, unit, base, exp) \
> +#define VM_STATS_DESC(stat, type, unit, base, exp, sz, param) \
> { \
> { \
> - STATS_DESC_COMMON(type, unit, base, exp), \
> + STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
> .offset = offsetof(struct kvm_vm_stat, stat) \
> }, \
> .name = #stat, \
> }
> -#define VCPU_STATS_DESC(stat, type, unit, base, exp) \
> +#define VCPU_STATS_DESC(stat, type, unit, base, exp, sz, param) \
> { \
> { \
> - STATS_DESC_COMMON(type, unit, base, exp), \
> + STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
> .offset = offsetof(struct kvm_vcpu_stat, stat) \
> }, \
> .name = #stat, \
> }
> /* SCOPE: VM, VM_GENERIC, VCPU, VCPU_GENERIC */
> -#define STATS_DESC(SCOPE, stat, type, unit, base, exp) \
> - SCOPE##_STATS_DESC(stat, type, unit, base, exp)
> +#define STATS_DESC(SCOPE, stat, type, unit, base, exp, sz, param) \
> + SCOPE##_STATS_DESC(stat, type, unit, base, exp, sz, param)
>
> #define STATS_DESC_CUMULATIVE(SCOPE, name, unit, base, exponent) \
> - STATS_DESC(SCOPE, name, KVM_STATS_TYPE_CUMULATIVE, unit, base, exponent)
> + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_CUMULATIVE, \
> + unit, base, exponent, 1, 0)
> #define STATS_DESC_INSTANT(SCOPE, name, unit, base, exponent) \
> - STATS_DESC(SCOPE, name, KVM_STATS_TYPE_INSTANT, unit, base, exponent)
> + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_INSTANT, \
> + unit, base, exponent, 1, 0)
> #define STATS_DESC_PEAK(SCOPE, name, unit, base, exponent) \
> - STATS_DESC(SCOPE, name, KVM_STATS_TYPE_PEAK, unit, base, exponent)
> + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_PEAK, \
> + unit, base, exponent, 1, 0)
> +#define STATS_DESC_LINEAR_HIST(SCOPE, name, unit, base, exponent, sz, param) \
> + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_LINEAR_HIST, \
> + unit, base, exponent, sz, param)
> +#define STATS_DESC_LOG_HIST(SCOPE, name, unit, base, exponent, sz, param) \
> + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_LOG_HIST, \
> + unit, base, exponent, sz, param)
>
> /* Cumulative counter, read/write */
> #define STATS_DESC_COUNTER(SCOPE, name) \
> @@ -1341,6 +1351,14 @@ struct _kvm_stats_desc {
> #define STATS_DESC_TIME_NSEC(SCOPE, name) \
> STATS_DESC_CUMULATIVE(SCOPE, name, KVM_STATS_UNIT_SECONDS, \
> KVM_STATS_BASE_POW10, -9)
> +/* Linear histogram for time in nanosecond */
> +#define STATS_DESC_LINHIST_TIME_NSEC(SCOPE, name, sz, bucket_size) \
> + STATS_DESC_LINEAR_HIST(SCOPE, name, KVM_STATS_UNIT_SECONDS, \
> + KVM_STATS_BASE_POW10, -9, sz, bucket_size)
> +/* Logarithmic histogram for time in nanosecond */
> +#define STATS_DESC_LOGHIST_TIME_NSEC(SCOPE, name, sz) \
> + STATS_DESC_LOG_HIST(SCOPE, name, KVM_STATS_UNIT_SECONDS, \
> + KVM_STATS_BASE_POW10, -9, sz, LOGHIST_BASE_2)
>
> #define KVM_GENERIC_VM_STATS() \
> STATS_DESC_COUNTER(VM_GENERIC, remote_tlb_flush)
> @@ -1354,10 +1372,15 @@ struct _kvm_stats_desc {
> STATS_DESC_TIME_NSEC(VCPU_GENERIC, halt_poll_fail_ns)
>
> extern struct dentry *kvm_debugfs_dir;
> +
> ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header,
> const struct _kvm_stats_desc *desc,
> void *stats, size_t size_stats,
> char __user *user_buffer, size_t size, loff_t *offset);
> +void kvm_stats_linear_hist_update(u64 *data, size_t size,
> + u64 value, size_t bucket_size);
> +void kvm_stats_log_hist_update(u64 *data, size_t size, u64 value);
> +
> extern const struct kvm_stats_header kvm_vm_stats_header;
> extern const struct _kvm_stats_desc kvm_vm_stats_desc[];
> extern const struct kvm_stats_header kvm_vcpu_stats_header;
> diff --git a/include/linux/kvm_types.h b/include/linux/kvm_types.h
> index ed6a985c5680..cc88cd676775 100644
> --- a/include/linux/kvm_types.h
> +++ b/include/linux/kvm_types.h
> @@ -76,6 +76,22 @@ struct kvm_mmu_memory_cache {
> };
> #endif
>
> +/* Constants used for histogram stats */
> +#define LINHIST_SIZE_SMALL 10
> +#define LINHIST_SIZE_MEDIUM 20
> +#define LINHIST_SIZE_LARGE 50
> +#define LINHIST_SIZE_XLARGE 100
nit: s/SIZE/BUCKET_COUNT/
> +#define LINHIST_BUCKET_SIZE_SMALL 10
> +#define LINHIST_BUCKET_SIZE_MEDIUM 100
> +#define LINHIST_BUCKET_SIZE_LARGE 1000
> +#define LINHIST_BUCKET_SIZE_XLARGE 10000
> +
> +#define LOGHIST_SIZE_SMALL 8
> +#define LOGHIST_SIZE_MEDIUM 16
> +#define LOGHIST_SIZE_LARGE 32
> +#define LOGHIST_SIZE_XLARGE 64
Ditto here.
> +#define LOGHIST_BASE_2 2
> +
> struct kvm_vm_stat_generic {
> u64 remote_tlb_flush;
> };
> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> index 68c9e6d8bbda..ff34a471d9ef 100644
> --- a/include/uapi/linux/kvm.h
> +++ b/include/uapi/linux/kvm.h
> @@ -1963,7 +1963,9 @@ struct kvm_stats_header {
> #define KVM_STATS_TYPE_CUMULATIVE (0x0 << KVM_STATS_TYPE_SHIFT)
> #define KVM_STATS_TYPE_INSTANT (0x1 << KVM_STATS_TYPE_SHIFT)
> #define KVM_STATS_TYPE_PEAK (0x2 << KVM_STATS_TYPE_SHIFT)
> -#define KVM_STATS_TYPE_MAX KVM_STATS_TYPE_PEAK
> +#define KVM_STATS_TYPE_LINEAR_HIST (0x3 << KVM_STATS_TYPE_SHIFT)
> +#define KVM_STATS_TYPE_LOG_HIST (0x4 << KVM_STATS_TYPE_SHIFT)
> +#define KVM_STATS_TYPE_MAX KVM_STATS_TYPE_LOG_HIST
>
> #define KVM_STATS_UNIT_SHIFT 4
> #define KVM_STATS_UNIT_MASK (0xF << KVM_STATS_UNIT_SHIFT)
> @@ -1987,7 +1989,10 @@ struct kvm_stats_header {
> * Every data item is of type __u64.
> * @offset: The offset of the stats to the start of stat structure in
> * struture kvm or kvm_vcpu.
> - * @unused: Unused field for future usage. Always 0 for now.
> + * @hist_param: A parameter value used for histogram stats. For linear
> + * histogram stats, it indicates the size of the bucket;
> + * For logarithmic histogram stats, it indicates the base
> + * of the logarithm. Only base of 2 is supported.
> * @name: The name string for the stats. Its size is indicated by the
> * &kvm_stats_header->name_size.
> */
> @@ -1996,7 +2001,7 @@ struct kvm_stats_desc {
> __s16 exponent;
> __u16 size;
> __u32 offset;
> - __u32 unused;
> + __u32 hist_param;
`hist_param` is vague. What about making this an anonymous union to make
the dual meaning explicit?
union {
/* Only used for KVM_STATS_TYPE_LOG_HIST. */
__u32 base;
/* Only used for KVM_STATS_TYPE_LINEAR_HIST. */
__u32 bucket_size;
};
It may make the STATS_DESC code a bit more complicated but the rest of
the code that uses it will be much more clear.
> char name[];
> };
>
> diff --git a/virt/kvm/binary_stats.c b/virt/kvm/binary_stats.c
> index e609d428811a..6eead6979a7f 100644
> --- a/virt/kvm/binary_stats.c
> +++ b/virt/kvm/binary_stats.c
> @@ -144,3 +144,39 @@ ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header,
> *offset = pos;
> return len;
> }
> +
> +/**
> + * kvm_stats_linear_hist_update() - Update bucket value for linear histogram
> + * statistics data.
> + *
> + * @data: start address of the stats data
> + * @size: the number of bucket of the stats data
> + * @value: the new value used to update the linear histogram's bucket
> + * @bucket_size: the size (width) of a bucket
> + */
> +void kvm_stats_linear_hist_update(u64 *data, size_t size,
> + u64 value, size_t bucket_size)
> +{
> + size_t index = value / bucket_size;
> +
> + if (index >= size)
> + index = size - 1;
nit: It would be simpler to use max().
size_t index = max(value / bucket_size, size - 1);
> + ++data[index];
> +}
> +
> +/**
> + * kvm_stats_log_hist_update() - Update bucket value for logarithmic histogram
> + * statistics data.
> + *
> + * @data: start address of the stats data
> + * @size: the number of bucket of the stats data
> + * @value: the new value used to update the logarithmic histogram's bucket
> + */
> +void kvm_stats_log_hist_update(u64 *data, size_t size, u64 value)
> +{
> + size_t index = fls64(value);
> +
> + if (index >= size)
> + index = size - 1;
Ditto here about using max().
> + ++data[index];
> +}
> --
> 2.32.0.93.g670b81a890-goog
>
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v1 1/4] KVM: stats: Support linear and logarithmic histogram statistics
@ 2021-07-08 21:01 ` David Matlack
0 siblings, 0 replies; 22+ messages in thread
From: David Matlack @ 2021-07-08 21:01 UTC (permalink / raw)
To: Jing Zhang
Cc: KVM, KVMPPC, Paolo Bonzini, Sean Christopherson, Jim Mattson,
Peter Shier, Oliver Upton, David Rientjes
On Tue, Jul 06, 2021 at 06:03:47PM +0000, Jing Zhang wrote:
> Add new types of KVM stats, linear and logarithmic histogram.
> Histogram are very useful for observing the value distribution
> of time or size related stats.
>
> Signed-off-by: Jing Zhang <jingzhangos@google.com>
> ---
> arch/arm64/kvm/guest.c | 4 ---
> arch/mips/kvm/mips.c | 4 ---
> arch/powerpc/kvm/book3s.c | 4 ---
> arch/powerpc/kvm/booke.c | 4 ---
> arch/s390/kvm/kvm-s390.c | 4 ---
> arch/x86/kvm/x86.c | 4 ---
> include/linux/kvm_host.h | 53 ++++++++++++++++++++++++++++-----------
> include/linux/kvm_types.h | 16 ++++++++++++
> include/uapi/linux/kvm.h | 11 +++++---
> virt/kvm/binary_stats.c | 36 ++++++++++++++++++++++++++
> 10 files changed, 98 insertions(+), 42 deletions(-)
>
> diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
> index 1512a8007a78..cb44d8756fa7 100644
> --- a/arch/arm64/kvm/guest.c
> +++ b/arch/arm64/kvm/guest.c
> @@ -31,8 +31,6 @@
> const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> KVM_GENERIC_VM_STATS()
> };
> -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) =
> - sizeof(struct kvm_vm_stat) / sizeof(u64));
>
> const struct kvm_stats_header kvm_vm_stats_header = {
> .name_size = KVM_STATS_NAME_SIZE,
> @@ -52,8 +50,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> STATS_DESC_COUNTER(VCPU, mmio_exit_kernel),
> STATS_DESC_COUNTER(VCPU, exits)
> };
> -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) =
> - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
>
> const struct kvm_stats_header kvm_vcpu_stats_header = {
> .name_size = KVM_STATS_NAME_SIZE,
> diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
> index af9dd029a4e1..75c6f264c626 100644
> --- a/arch/mips/kvm/mips.c
> +++ b/arch/mips/kvm/mips.c
> @@ -41,8 +41,6 @@
> const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> KVM_GENERIC_VM_STATS()
> };
> -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) =
> - sizeof(struct kvm_vm_stat) / sizeof(u64));
>
> const struct kvm_stats_header kvm_vm_stats_header = {
> .name_size = KVM_STATS_NAME_SIZE,
> @@ -85,8 +83,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> STATS_DESC_COUNTER(VCPU, vz_cpucfg_exits),
> #endif
> };
> -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) =
> - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
>
> const struct kvm_stats_header kvm_vcpu_stats_header = {
> .name_size = KVM_STATS_NAME_SIZE,
> diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
> index 79833f78d1da..5cc6e90095b0 100644
> --- a/arch/powerpc/kvm/book3s.c
> +++ b/arch/powerpc/kvm/book3s.c
> @@ -43,8 +43,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> STATS_DESC_ICOUNTER(VM, num_2M_pages),
> STATS_DESC_ICOUNTER(VM, num_1G_pages)
> };
> -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) =
> - sizeof(struct kvm_vm_stat) / sizeof(u64));
>
> const struct kvm_stats_header kvm_vm_stats_header = {
> .name_size = KVM_STATS_NAME_SIZE,
> @@ -88,8 +86,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> STATS_DESC_COUNTER(VCPU, pthru_host),
> STATS_DESC_COUNTER(VCPU, pthru_bad_aff)
> };
> -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) =
> - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
>
> const struct kvm_stats_header kvm_vcpu_stats_header = {
> .name_size = KVM_STATS_NAME_SIZE,
> diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
> index 551b30d84aee..5ed6c235e059 100644
> --- a/arch/powerpc/kvm/booke.c
> +++ b/arch/powerpc/kvm/booke.c
> @@ -41,8 +41,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> STATS_DESC_ICOUNTER(VM, num_2M_pages),
> STATS_DESC_ICOUNTER(VM, num_1G_pages)
> };
> -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) =
> - sizeof(struct kvm_vm_stat) / sizeof(u64));
>
> const struct kvm_stats_header kvm_vm_stats_header = {
> .name_size = KVM_STATS_NAME_SIZE,
> @@ -79,8 +77,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> STATS_DESC_COUNTER(VCPU, pthru_host),
> STATS_DESC_COUNTER(VCPU, pthru_bad_aff)
> };
> -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) =
> - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
>
> const struct kvm_stats_header kvm_vcpu_stats_header = {
> .name_size = KVM_STATS_NAME_SIZE,
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index 1695f0ced5ba..7610d33d319b 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -66,8 +66,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> STATS_DESC_COUNTER(VM, inject_service_signal),
> STATS_DESC_COUNTER(VM, inject_virtio)
> };
> -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) =
> - sizeof(struct kvm_vm_stat) / sizeof(u64));
>
> const struct kvm_stats_header kvm_vm_stats_header = {
> .name_size = KVM_STATS_NAME_SIZE,
> @@ -174,8 +172,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> STATS_DESC_COUNTER(VCPU, diagnose_other),
> STATS_DESC_COUNTER(VCPU, pfault_sync)
> };
> -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) =
> - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
>
> const struct kvm_stats_header kvm_vcpu_stats_header = {
> .name_size = KVM_STATS_NAME_SIZE,
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 8166ad113fb2..b94a80ad5b8d 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -239,8 +239,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> STATS_DESC_ICOUNTER(VM, nx_lpage_splits),
> STATS_DESC_PCOUNTER(VM, max_mmu_page_hash_collisions)
> };
> -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) =
> - sizeof(struct kvm_vm_stat) / sizeof(u64));
>
> const struct kvm_stats_header kvm_vm_stats_header = {
> .name_size = KVM_STATS_NAME_SIZE,
> @@ -280,8 +278,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> STATS_DESC_COUNTER(VCPU, directed_yield_successful),
> STATS_DESC_ICOUNTER(VCPU, guest_mode)
> };
> -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) =
> - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
>
> const struct kvm_stats_header kvm_vcpu_stats_header = {
> .name_size = KVM_STATS_NAME_SIZE,
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index ae7735b490b4..356af173114d 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -1273,56 +1273,66 @@ struct _kvm_stats_desc {
> char name[KVM_STATS_NAME_SIZE];
> };
>
> -#define STATS_DESC_COMMON(type, unit, base, exp) \
> +#define STATS_DESC_COMMON(type, unit, base, exp, sz, param) \
> .flags = type | unit | base | \
> BUILD_BUG_ON_ZERO(type & ~KVM_STATS_TYPE_MASK) | \
> BUILD_BUG_ON_ZERO(unit & ~KVM_STATS_UNIT_MASK) | \
> BUILD_BUG_ON_ZERO(base & ~KVM_STATS_BASE_MASK), \
> .exponent = exp, \
> - .size = 1
> + .size = sz, \
> + .hist_param = param
>
> -#define VM_GENERIC_STATS_DESC(stat, type, unit, base, exp) \
> +#define VM_GENERIC_STATS_DESC(stat, type, unit, base, exp, sz, param) \
> { \
> { \
> - STATS_DESC_COMMON(type, unit, base, exp), \
> + STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
> .offset = offsetof(struct kvm_vm_stat, generic.stat) \
> }, \
> .name = #stat, \
> }
> -#define VCPU_GENERIC_STATS_DESC(stat, type, unit, base, exp) \
> +#define VCPU_GENERIC_STATS_DESC(stat, type, unit, base, exp, sz, param) \
> { \
> { \
> - STATS_DESC_COMMON(type, unit, base, exp), \
> + STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
> .offset = offsetof(struct kvm_vcpu_stat, generic.stat) \
> }, \
> .name = #stat, \
> }
> -#define VM_STATS_DESC(stat, type, unit, base, exp) \
> +#define VM_STATS_DESC(stat, type, unit, base, exp, sz, param) \
> { \
> { \
> - STATS_DESC_COMMON(type, unit, base, exp), \
> + STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
> .offset = offsetof(struct kvm_vm_stat, stat) \
> }, \
> .name = #stat, \
> }
> -#define VCPU_STATS_DESC(stat, type, unit, base, exp) \
> +#define VCPU_STATS_DESC(stat, type, unit, base, exp, sz, param) \
> { \
> { \
> - STATS_DESC_COMMON(type, unit, base, exp), \
> + STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
> .offset = offsetof(struct kvm_vcpu_stat, stat) \
> }, \
> .name = #stat, \
> }
> /* SCOPE: VM, VM_GENERIC, VCPU, VCPU_GENERIC */
> -#define STATS_DESC(SCOPE, stat, type, unit, base, exp) \
> - SCOPE##_STATS_DESC(stat, type, unit, base, exp)
> +#define STATS_DESC(SCOPE, stat, type, unit, base, exp, sz, param) \
> + SCOPE##_STATS_DESC(stat, type, unit, base, exp, sz, param)
>
> #define STATS_DESC_CUMULATIVE(SCOPE, name, unit, base, exponent) \
> - STATS_DESC(SCOPE, name, KVM_STATS_TYPE_CUMULATIVE, unit, base, exponent)
> + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_CUMULATIVE, \
> + unit, base, exponent, 1, 0)
> #define STATS_DESC_INSTANT(SCOPE, name, unit, base, exponent) \
> - STATS_DESC(SCOPE, name, KVM_STATS_TYPE_INSTANT, unit, base, exponent)
> + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_INSTANT, \
> + unit, base, exponent, 1, 0)
> #define STATS_DESC_PEAK(SCOPE, name, unit, base, exponent) \
> - STATS_DESC(SCOPE, name, KVM_STATS_TYPE_PEAK, unit, base, exponent)
> + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_PEAK, \
> + unit, base, exponent, 1, 0)
> +#define STATS_DESC_LINEAR_HIST(SCOPE, name, unit, base, exponent, sz, param) \
> + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_LINEAR_HIST, \
> + unit, base, exponent, sz, param)
> +#define STATS_DESC_LOG_HIST(SCOPE, name, unit, base, exponent, sz, param) \
> + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_LOG_HIST, \
> + unit, base, exponent, sz, param)
>
> /* Cumulative counter, read/write */
> #define STATS_DESC_COUNTER(SCOPE, name) \
> @@ -1341,6 +1351,14 @@ struct _kvm_stats_desc {
> #define STATS_DESC_TIME_NSEC(SCOPE, name) \
> STATS_DESC_CUMULATIVE(SCOPE, name, KVM_STATS_UNIT_SECONDS, \
> KVM_STATS_BASE_POW10, -9)
> +/* Linear histogram for time in nanosecond */
> +#define STATS_DESC_LINHIST_TIME_NSEC(SCOPE, name, sz, bucket_size) \
> + STATS_DESC_LINEAR_HIST(SCOPE, name, KVM_STATS_UNIT_SECONDS, \
> + KVM_STATS_BASE_POW10, -9, sz, bucket_size)
> +/* Logarithmic histogram for time in nanosecond */
> +#define STATS_DESC_LOGHIST_TIME_NSEC(SCOPE, name, sz) \
> + STATS_DESC_LOG_HIST(SCOPE, name, KVM_STATS_UNIT_SECONDS, \
> + KVM_STATS_BASE_POW10, -9, sz, LOGHIST_BASE_2)
>
> #define KVM_GENERIC_VM_STATS() \
> STATS_DESC_COUNTER(VM_GENERIC, remote_tlb_flush)
> @@ -1354,10 +1372,15 @@ struct _kvm_stats_desc {
> STATS_DESC_TIME_NSEC(VCPU_GENERIC, halt_poll_fail_ns)
>
> extern struct dentry *kvm_debugfs_dir;
> +
> ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header,
> const struct _kvm_stats_desc *desc,
> void *stats, size_t size_stats,
> char __user *user_buffer, size_t size, loff_t *offset);
> +void kvm_stats_linear_hist_update(u64 *data, size_t size,
> + u64 value, size_t bucket_size);
> +void kvm_stats_log_hist_update(u64 *data, size_t size, u64 value);
> +
> extern const struct kvm_stats_header kvm_vm_stats_header;
> extern const struct _kvm_stats_desc kvm_vm_stats_desc[];
> extern const struct kvm_stats_header kvm_vcpu_stats_header;
> diff --git a/include/linux/kvm_types.h b/include/linux/kvm_types.h
> index ed6a985c5680..cc88cd676775 100644
> --- a/include/linux/kvm_types.h
> +++ b/include/linux/kvm_types.h
> @@ -76,6 +76,22 @@ struct kvm_mmu_memory_cache {
> };
> #endif
>
> +/* Constants used for histogram stats */
> +#define LINHIST_SIZE_SMALL 10
> +#define LINHIST_SIZE_MEDIUM 20
> +#define LINHIST_SIZE_LARGE 50
> +#define LINHIST_SIZE_XLARGE 100
nit: s/SIZE/BUCKET_COUNT/
> +#define LINHIST_BUCKET_SIZE_SMALL 10
> +#define LINHIST_BUCKET_SIZE_MEDIUM 100
> +#define LINHIST_BUCKET_SIZE_LARGE 1000
> +#define LINHIST_BUCKET_SIZE_XLARGE 10000
> +
> +#define LOGHIST_SIZE_SMALL 8
> +#define LOGHIST_SIZE_MEDIUM 16
> +#define LOGHIST_SIZE_LARGE 32
> +#define LOGHIST_SIZE_XLARGE 64
Ditto here.
> +#define LOGHIST_BASE_2 2
> +
> struct kvm_vm_stat_generic {
> u64 remote_tlb_flush;
> };
> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> index 68c9e6d8bbda..ff34a471d9ef 100644
> --- a/include/uapi/linux/kvm.h
> +++ b/include/uapi/linux/kvm.h
> @@ -1963,7 +1963,9 @@ struct kvm_stats_header {
> #define KVM_STATS_TYPE_CUMULATIVE (0x0 << KVM_STATS_TYPE_SHIFT)
> #define KVM_STATS_TYPE_INSTANT (0x1 << KVM_STATS_TYPE_SHIFT)
> #define KVM_STATS_TYPE_PEAK (0x2 << KVM_STATS_TYPE_SHIFT)
> -#define KVM_STATS_TYPE_MAX KVM_STATS_TYPE_PEAK
> +#define KVM_STATS_TYPE_LINEAR_HIST (0x3 << KVM_STATS_TYPE_SHIFT)
> +#define KVM_STATS_TYPE_LOG_HIST (0x4 << KVM_STATS_TYPE_SHIFT)
> +#define KVM_STATS_TYPE_MAX KVM_STATS_TYPE_LOG_HIST
>
> #define KVM_STATS_UNIT_SHIFT 4
> #define KVM_STATS_UNIT_MASK (0xF << KVM_STATS_UNIT_SHIFT)
> @@ -1987,7 +1989,10 @@ struct kvm_stats_header {
> * Every data item is of type __u64.
> * @offset: The offset of the stats to the start of stat structure in
> * struture kvm or kvm_vcpu.
> - * @unused: Unused field for future usage. Always 0 for now.
> + * @hist_param: A parameter value used for histogram stats. For linear
> + * histogram stats, it indicates the size of the bucket;
> + * For logarithmic histogram stats, it indicates the base
> + * of the logarithm. Only base of 2 is supported.
> * @name: The name string for the stats. Its size is indicated by the
> * &kvm_stats_header->name_size.
> */
> @@ -1996,7 +2001,7 @@ struct kvm_stats_desc {
> __s16 exponent;
> __u16 size;
> __u32 offset;
> - __u32 unused;
> + __u32 hist_param;
`hist_param` is vague. What about making this an anonymous union to make
the dual meaning explicit?
union {
/* Only used for KVM_STATS_TYPE_LOG_HIST. */
__u32 base;
/* Only used for KVM_STATS_TYPE_LINEAR_HIST. */
__u32 bucket_size;
};
It may make the STATS_DESC code a bit more complicated but the rest of
the code that uses it will be much more clear.
> char name[];
> };
>
> diff --git a/virt/kvm/binary_stats.c b/virt/kvm/binary_stats.c
> index e609d428811a..6eead6979a7f 100644
> --- a/virt/kvm/binary_stats.c
> +++ b/virt/kvm/binary_stats.c
> @@ -144,3 +144,39 @@ ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header,
> *offset = pos;
> return len;
> }
> +
> +/**
> + * kvm_stats_linear_hist_update() - Update bucket value for linear histogram
> + * statistics data.
> + *
> + * @data: start address of the stats data
> + * @size: the number of bucket of the stats data
> + * @value: the new value used to update the linear histogram's bucket
> + * @bucket_size: the size (width) of a bucket
> + */
> +void kvm_stats_linear_hist_update(u64 *data, size_t size,
> + u64 value, size_t bucket_size)
> +{
> + size_t index = value / bucket_size;
> +
> + if (index >= size)
> + index = size - 1;
nit: It would be simpler to use max().
size_t index = max(value / bucket_size, size - 1);
> + ++data[index];
> +}
> +
> +/**
> + * kvm_stats_log_hist_update() - Update bucket value for logarithmic histogram
> + * statistics data.
> + *
> + * @data: start address of the stats data
> + * @size: the number of bucket of the stats data
> + * @value: the new value used to update the logarithmic histogram's bucket
> + */
> +void kvm_stats_log_hist_update(u64 *data, size_t size, u64 value)
> +{
> + size_t index = fls64(value);
> +
> + if (index >= size)
> + index = size - 1;
Ditto here about using max().
> + ++data[index];
> +}
> --
> 2.32.0.93.g670b81a890-goog
>
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v1 1/4] KVM: stats: Support linear and logarithmic histogram statistics
2021-07-08 21:01 ` David Matlack
@ 2021-07-08 21:40 ` Jing Zhang
-1 siblings, 0 replies; 22+ messages in thread
From: Jing Zhang @ 2021-07-08 21:40 UTC (permalink / raw)
To: David Matlack
Cc: KVM, KVMPPC, Paolo Bonzini, Sean Christopherson, Jim Mattson,
Peter Shier, Oliver Upton, David Rientjes
On Thu, Jul 8, 2021 at 4:01 PM David Matlack <dmatlack@google.com> wrote:
>
> On Tue, Jul 06, 2021 at 06:03:47PM +0000, Jing Zhang wrote:
> > Add new types of KVM stats, linear and logarithmic histogram.
> > Histogram are very useful for observing the value distribution
> > of time or size related stats.
> >
> > Signed-off-by: Jing Zhang <jingzhangos@google.com>
> > ---
> > arch/arm64/kvm/guest.c | 4 ---
> > arch/mips/kvm/mips.c | 4 ---
> > arch/powerpc/kvm/book3s.c | 4 ---
> > arch/powerpc/kvm/booke.c | 4 ---
> > arch/s390/kvm/kvm-s390.c | 4 ---
> > arch/x86/kvm/x86.c | 4 ---
> > include/linux/kvm_host.h | 53 ++++++++++++++++++++++++++++-----------
> > include/linux/kvm_types.h | 16 ++++++++++++
> > include/uapi/linux/kvm.h | 11 +++++---
> > virt/kvm/binary_stats.c | 36 ++++++++++++++++++++++++++
> > 10 files changed, 98 insertions(+), 42 deletions(-)
> >
> > diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
> > index 1512a8007a78..cb44d8756fa7 100644
> > --- a/arch/arm64/kvm/guest.c
> > +++ b/arch/arm64/kvm/guest.c
> > @@ -31,8 +31,6 @@
> > const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> > KVM_GENERIC_VM_STATS()
> > };
> > -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
> > - sizeof(struct kvm_vm_stat) / sizeof(u64));
> >
> > const struct kvm_stats_header kvm_vm_stats_header = {
> > .name_size = KVM_STATS_NAME_SIZE,
> > @@ -52,8 +50,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> > STATS_DESC_COUNTER(VCPU, mmio_exit_kernel),
> > STATS_DESC_COUNTER(VCPU, exits)
> > };
> > -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) ==
> > - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
> >
> > const struct kvm_stats_header kvm_vcpu_stats_header = {
> > .name_size = KVM_STATS_NAME_SIZE,
> > diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
> > index af9dd029a4e1..75c6f264c626 100644
> > --- a/arch/mips/kvm/mips.c
> > +++ b/arch/mips/kvm/mips.c
> > @@ -41,8 +41,6 @@
> > const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> > KVM_GENERIC_VM_STATS()
> > };
> > -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
> > - sizeof(struct kvm_vm_stat) / sizeof(u64));
> >
> > const struct kvm_stats_header kvm_vm_stats_header = {
> > .name_size = KVM_STATS_NAME_SIZE,
> > @@ -85,8 +83,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> > STATS_DESC_COUNTER(VCPU, vz_cpucfg_exits),
> > #endif
> > };
> > -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) ==
> > - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
> >
> > const struct kvm_stats_header kvm_vcpu_stats_header = {
> > .name_size = KVM_STATS_NAME_SIZE,
> > diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
> > index 79833f78d1da..5cc6e90095b0 100644
> > --- a/arch/powerpc/kvm/book3s.c
> > +++ b/arch/powerpc/kvm/book3s.c
> > @@ -43,8 +43,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> > STATS_DESC_ICOUNTER(VM, num_2M_pages),
> > STATS_DESC_ICOUNTER(VM, num_1G_pages)
> > };
> > -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
> > - sizeof(struct kvm_vm_stat) / sizeof(u64));
> >
> > const struct kvm_stats_header kvm_vm_stats_header = {
> > .name_size = KVM_STATS_NAME_SIZE,
> > @@ -88,8 +86,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> > STATS_DESC_COUNTER(VCPU, pthru_host),
> > STATS_DESC_COUNTER(VCPU, pthru_bad_aff)
> > };
> > -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) ==
> > - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
> >
> > const struct kvm_stats_header kvm_vcpu_stats_header = {
> > .name_size = KVM_STATS_NAME_SIZE,
> > diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
> > index 551b30d84aee..5ed6c235e059 100644
> > --- a/arch/powerpc/kvm/booke.c
> > +++ b/arch/powerpc/kvm/booke.c
> > @@ -41,8 +41,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> > STATS_DESC_ICOUNTER(VM, num_2M_pages),
> > STATS_DESC_ICOUNTER(VM, num_1G_pages)
> > };
> > -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
> > - sizeof(struct kvm_vm_stat) / sizeof(u64));
> >
> > const struct kvm_stats_header kvm_vm_stats_header = {
> > .name_size = KVM_STATS_NAME_SIZE,
> > @@ -79,8 +77,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> > STATS_DESC_COUNTER(VCPU, pthru_host),
> > STATS_DESC_COUNTER(VCPU, pthru_bad_aff)
> > };
> > -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) ==
> > - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
> >
> > const struct kvm_stats_header kvm_vcpu_stats_header = {
> > .name_size = KVM_STATS_NAME_SIZE,
> > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> > index 1695f0ced5ba..7610d33d319b 100644
> > --- a/arch/s390/kvm/kvm-s390.c
> > +++ b/arch/s390/kvm/kvm-s390.c
> > @@ -66,8 +66,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> > STATS_DESC_COUNTER(VM, inject_service_signal),
> > STATS_DESC_COUNTER(VM, inject_virtio)
> > };
> > -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
> > - sizeof(struct kvm_vm_stat) / sizeof(u64));
> >
> > const struct kvm_stats_header kvm_vm_stats_header = {
> > .name_size = KVM_STATS_NAME_SIZE,
> > @@ -174,8 +172,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> > STATS_DESC_COUNTER(VCPU, diagnose_other),
> > STATS_DESC_COUNTER(VCPU, pfault_sync)
> > };
> > -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) ==
> > - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
> >
> > const struct kvm_stats_header kvm_vcpu_stats_header = {
> > .name_size = KVM_STATS_NAME_SIZE,
> > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> > index 8166ad113fb2..b94a80ad5b8d 100644
> > --- a/arch/x86/kvm/x86.c
> > +++ b/arch/x86/kvm/x86.c
> > @@ -239,8 +239,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> > STATS_DESC_ICOUNTER(VM, nx_lpage_splits),
> > STATS_DESC_PCOUNTER(VM, max_mmu_page_hash_collisions)
> > };
> > -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
> > - sizeof(struct kvm_vm_stat) / sizeof(u64));
> >
> > const struct kvm_stats_header kvm_vm_stats_header = {
> > .name_size = KVM_STATS_NAME_SIZE,
> > @@ -280,8 +278,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> > STATS_DESC_COUNTER(VCPU, directed_yield_successful),
> > STATS_DESC_ICOUNTER(VCPU, guest_mode)
> > };
> > -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) ==
> > - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
> >
> > const struct kvm_stats_header kvm_vcpu_stats_header = {
> > .name_size = KVM_STATS_NAME_SIZE,
> > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> > index ae7735b490b4..356af173114d 100644
> > --- a/include/linux/kvm_host.h
> > +++ b/include/linux/kvm_host.h
> > @@ -1273,56 +1273,66 @@ struct _kvm_stats_desc {
> > char name[KVM_STATS_NAME_SIZE];
> > };
> >
> > -#define STATS_DESC_COMMON(type, unit, base, exp) \
> > +#define STATS_DESC_COMMON(type, unit, base, exp, sz, param) \
> > .flags = type | unit | base | \
> > BUILD_BUG_ON_ZERO(type & ~KVM_STATS_TYPE_MASK) | \
> > BUILD_BUG_ON_ZERO(unit & ~KVM_STATS_UNIT_MASK) | \
> > BUILD_BUG_ON_ZERO(base & ~KVM_STATS_BASE_MASK), \
> > .exponent = exp, \
> > - .size = 1
> > + .size = sz, \
> > + .hist_param = param
> >
> > -#define VM_GENERIC_STATS_DESC(stat, type, unit, base, exp) \
> > +#define VM_GENERIC_STATS_DESC(stat, type, unit, base, exp, sz, param) \
> > { \
> > { \
> > - STATS_DESC_COMMON(type, unit, base, exp), \
> > + STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
> > .offset = offsetof(struct kvm_vm_stat, generic.stat) \
> > }, \
> > .name = #stat, \
> > }
> > -#define VCPU_GENERIC_STATS_DESC(stat, type, unit, base, exp) \
> > +#define VCPU_GENERIC_STATS_DESC(stat, type, unit, base, exp, sz, param) \
> > { \
> > { \
> > - STATS_DESC_COMMON(type, unit, base, exp), \
> > + STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
> > .offset = offsetof(struct kvm_vcpu_stat, generic.stat) \
> > }, \
> > .name = #stat, \
> > }
> > -#define VM_STATS_DESC(stat, type, unit, base, exp) \
> > +#define VM_STATS_DESC(stat, type, unit, base, exp, sz, param) \
> > { \
> > { \
> > - STATS_DESC_COMMON(type, unit, base, exp), \
> > + STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
> > .offset = offsetof(struct kvm_vm_stat, stat) \
> > }, \
> > .name = #stat, \
> > }
> > -#define VCPU_STATS_DESC(stat, type, unit, base, exp) \
> > +#define VCPU_STATS_DESC(stat, type, unit, base, exp, sz, param) \
> > { \
> > { \
> > - STATS_DESC_COMMON(type, unit, base, exp), \
> > + STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
> > .offset = offsetof(struct kvm_vcpu_stat, stat) \
> > }, \
> > .name = #stat, \
> > }
> > /* SCOPE: VM, VM_GENERIC, VCPU, VCPU_GENERIC */
> > -#define STATS_DESC(SCOPE, stat, type, unit, base, exp) \
> > - SCOPE##_STATS_DESC(stat, type, unit, base, exp)
> > +#define STATS_DESC(SCOPE, stat, type, unit, base, exp, sz, param) \
> > + SCOPE##_STATS_DESC(stat, type, unit, base, exp, sz, param)
> >
> > #define STATS_DESC_CUMULATIVE(SCOPE, name, unit, base, exponent) \
> > - STATS_DESC(SCOPE, name, KVM_STATS_TYPE_CUMULATIVE, unit, base, exponent)
> > + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_CUMULATIVE, \
> > + unit, base, exponent, 1, 0)
> > #define STATS_DESC_INSTANT(SCOPE, name, unit, base, exponent) \
> > - STATS_DESC(SCOPE, name, KVM_STATS_TYPE_INSTANT, unit, base, exponent)
> > + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_INSTANT, \
> > + unit, base, exponent, 1, 0)
> > #define STATS_DESC_PEAK(SCOPE, name, unit, base, exponent) \
> > - STATS_DESC(SCOPE, name, KVM_STATS_TYPE_PEAK, unit, base, exponent)
> > + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_PEAK, \
> > + unit, base, exponent, 1, 0)
> > +#define STATS_DESC_LINEAR_HIST(SCOPE, name, unit, base, exponent, sz, param) \
> > + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_LINEAR_HIST, \
> > + unit, base, exponent, sz, param)
> > +#define STATS_DESC_LOG_HIST(SCOPE, name, unit, base, exponent, sz, param) \
> > + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_LOG_HIST, \
> > + unit, base, exponent, sz, param)
> >
> > /* Cumulative counter, read/write */
> > #define STATS_DESC_COUNTER(SCOPE, name) \
> > @@ -1341,6 +1351,14 @@ struct _kvm_stats_desc {
> > #define STATS_DESC_TIME_NSEC(SCOPE, name) \
> > STATS_DESC_CUMULATIVE(SCOPE, name, KVM_STATS_UNIT_SECONDS, \
> > KVM_STATS_BASE_POW10, -9)
> > +/* Linear histogram for time in nanosecond */
> > +#define STATS_DESC_LINHIST_TIME_NSEC(SCOPE, name, sz, bucket_size) \
> > + STATS_DESC_LINEAR_HIST(SCOPE, name, KVM_STATS_UNIT_SECONDS, \
> > + KVM_STATS_BASE_POW10, -9, sz, bucket_size)
> > +/* Logarithmic histogram for time in nanosecond */
> > +#define STATS_DESC_LOGHIST_TIME_NSEC(SCOPE, name, sz) \
> > + STATS_DESC_LOG_HIST(SCOPE, name, KVM_STATS_UNIT_SECONDS, \
> > + KVM_STATS_BASE_POW10, -9, sz, LOGHIST_BASE_2)
> >
> > #define KVM_GENERIC_VM_STATS() \
> > STATS_DESC_COUNTER(VM_GENERIC, remote_tlb_flush)
> > @@ -1354,10 +1372,15 @@ struct _kvm_stats_desc {
> > STATS_DESC_TIME_NSEC(VCPU_GENERIC, halt_poll_fail_ns)
> >
> > extern struct dentry *kvm_debugfs_dir;
> > +
> > ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header,
> > const struct _kvm_stats_desc *desc,
> > void *stats, size_t size_stats,
> > char __user *user_buffer, size_t size, loff_t *offset);
> > +void kvm_stats_linear_hist_update(u64 *data, size_t size,
> > + u64 value, size_t bucket_size);
> > +void kvm_stats_log_hist_update(u64 *data, size_t size, u64 value);
> > +
> > extern const struct kvm_stats_header kvm_vm_stats_header;
> > extern const struct _kvm_stats_desc kvm_vm_stats_desc[];
> > extern const struct kvm_stats_header kvm_vcpu_stats_header;
> > diff --git a/include/linux/kvm_types.h b/include/linux/kvm_types.h
> > index ed6a985c5680..cc88cd676775 100644
> > --- a/include/linux/kvm_types.h
> > +++ b/include/linux/kvm_types.h
> > @@ -76,6 +76,22 @@ struct kvm_mmu_memory_cache {
> > };
> > #endif
> >
> > +/* Constants used for histogram stats */
> > +#define LINHIST_SIZE_SMALL 10
> > +#define LINHIST_SIZE_MEDIUM 20
> > +#define LINHIST_SIZE_LARGE 50
> > +#define LINHIST_SIZE_XLARGE 100
>
> nit: s/SIZE/BUCKET_COUNT/
>
Sure, it makes more sense.
> > +#define LINHIST_BUCKET_SIZE_SMALL 10
> > +#define LINHIST_BUCKET_SIZE_MEDIUM 100
> > +#define LINHIST_BUCKET_SIZE_LARGE 1000
> > +#define LINHIST_BUCKET_SIZE_XLARGE 10000
> > +
> > +#define LOGHIST_SIZE_SMALL 8
> > +#define LOGHIST_SIZE_MEDIUM 16
> > +#define LOGHIST_SIZE_LARGE 32
> > +#define LOGHIST_SIZE_XLARGE 64
>
> Ditto here.
>
Will do.
> > +#define LOGHIST_BASE_2 2
> > +
> > struct kvm_vm_stat_generic {
> > u64 remote_tlb_flush;
> > };
> > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> > index 68c9e6d8bbda..ff34a471d9ef 100644
> > --- a/include/uapi/linux/kvm.h
> > +++ b/include/uapi/linux/kvm.h
> > @@ -1963,7 +1963,9 @@ struct kvm_stats_header {
> > #define KVM_STATS_TYPE_CUMULATIVE (0x0 << KVM_STATS_TYPE_SHIFT)
> > #define KVM_STATS_TYPE_INSTANT (0x1 << KVM_STATS_TYPE_SHIFT)
> > #define KVM_STATS_TYPE_PEAK (0x2 << KVM_STATS_TYPE_SHIFT)
> > -#define KVM_STATS_TYPE_MAX KVM_STATS_TYPE_PEAK
> > +#define KVM_STATS_TYPE_LINEAR_HIST (0x3 << KVM_STATS_TYPE_SHIFT)
> > +#define KVM_STATS_TYPE_LOG_HIST (0x4 << KVM_STATS_TYPE_SHIFT)
> > +#define KVM_STATS_TYPE_MAX KVM_STATS_TYPE_LOG_HIST
> >
> > #define KVM_STATS_UNIT_SHIFT 4
> > #define KVM_STATS_UNIT_MASK (0xF << KVM_STATS_UNIT_SHIFT)
> > @@ -1987,7 +1989,10 @@ struct kvm_stats_header {
> > * Every data item is of type __u64.
> > * @offset: The offset of the stats to the start of stat structure in
> > * struture kvm or kvm_vcpu.
> > - * @unused: Unused field for future usage. Always 0 for now.
> > + * @hist_param: A parameter value used for histogram stats. For linear
> > + * histogram stats, it indicates the size of the bucket;
> > + * For logarithmic histogram stats, it indicates the base
> > + * of the logarithm. Only base of 2 is supported.
> > * @name: The name string for the stats. Its size is indicated by the
> > * &kvm_stats_header->name_size.
> > */
> > @@ -1996,7 +2001,7 @@ struct kvm_stats_desc {
> > __s16 exponent;
> > __u16 size;
> > __u32 offset;
> > - __u32 unused;
> > + __u32 hist_param;
>
> `hist_param` is vague. What about making this an anonymous union to make
> the dual meaning explicit?
>
> union {
> /* Only used for KVM_STATS_TYPE_LOG_HIST. */
> __u32 base;
> /* Only used for KVM_STATS_TYPE_LINEAR_HIST. */
> __u32 bucket_size;
> };
>
> It may make the STATS_DESC code a bit more complicated but the rest of
> the code that uses it will be much more clear.
>
Since we only support base-2 log hist, maybe it is not necessary to
have the base field.
The reason to only support base-2 log hist is that its range is
already large enough for
any stats.
Will just change hist_param to bucket_size.
> > char name[];
> > };
> >
> > diff --git a/virt/kvm/binary_stats.c b/virt/kvm/binary_stats.c
> > index e609d428811a..6eead6979a7f 100644
> > --- a/virt/kvm/binary_stats.c
> > +++ b/virt/kvm/binary_stats.c
> > @@ -144,3 +144,39 @@ ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header,
> > *offset = pos;
> > return len;
> > }
> > +
> > +/**
> > + * kvm_stats_linear_hist_update() - Update bucket value for linear histogram
> > + * statistics data.
> > + *
> > + * @data: start address of the stats data
> > + * @size: the number of bucket of the stats data
> > + * @value: the new value used to update the linear histogram's bucket
> > + * @bucket_size: the size (width) of a bucket
> > + */
> > +void kvm_stats_linear_hist_update(u64 *data, size_t size,
> > + u64 value, size_t bucket_size)
> > +{
> > + size_t index = value / bucket_size;
> > +
> > + if (index >= size)
> > + index = size - 1;
>
> nit: It would be simpler to use max().
>
> size_t index = max(value / bucket_size, size - 1);
>
Will do.
> > + ++data[index];
> > +}
> > +
> > +/**
> > + * kvm_stats_log_hist_update() - Update bucket value for logarithmic histogram
> > + * statistics data.
> > + *
> > + * @data: start address of the stats data
> > + * @size: the number of bucket of the stats data
> > + * @value: the new value used to update the logarithmic histogram's bucket
> > + */
> > +void kvm_stats_log_hist_update(u64 *data, size_t size, u64 value)
> > +{
> > + size_t index = fls64(value);
> > +
> > + if (index >= size)
> > + index = size - 1;
>
> Ditto here about using max().
>
Will do.
> > + ++data[index];
> > +}
> > --
> > 2.32.0.93.g670b81a890-goog
> >
Thanks,
Jing
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v1 1/4] KVM: stats: Support linear and logarithmic histogram statistics
@ 2021-07-08 21:40 ` Jing Zhang
0 siblings, 0 replies; 22+ messages in thread
From: Jing Zhang @ 2021-07-08 21:40 UTC (permalink / raw)
To: David Matlack
Cc: KVM, KVMPPC, Paolo Bonzini, Sean Christopherson, Jim Mattson,
Peter Shier, Oliver Upton, David Rientjes
On Thu, Jul 8, 2021 at 4:01 PM David Matlack <dmatlack@google.com> wrote:
>
> On Tue, Jul 06, 2021 at 06:03:47PM +0000, Jing Zhang wrote:
> > Add new types of KVM stats, linear and logarithmic histogram.
> > Histogram are very useful for observing the value distribution
> > of time or size related stats.
> >
> > Signed-off-by: Jing Zhang <jingzhangos@google.com>
> > ---
> > arch/arm64/kvm/guest.c | 4 ---
> > arch/mips/kvm/mips.c | 4 ---
> > arch/powerpc/kvm/book3s.c | 4 ---
> > arch/powerpc/kvm/booke.c | 4 ---
> > arch/s390/kvm/kvm-s390.c | 4 ---
> > arch/x86/kvm/x86.c | 4 ---
> > include/linux/kvm_host.h | 53 ++++++++++++++++++++++++++++-----------
> > include/linux/kvm_types.h | 16 ++++++++++++
> > include/uapi/linux/kvm.h | 11 +++++---
> > virt/kvm/binary_stats.c | 36 ++++++++++++++++++++++++++
> > 10 files changed, 98 insertions(+), 42 deletions(-)
> >
> > diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
> > index 1512a8007a78..cb44d8756fa7 100644
> > --- a/arch/arm64/kvm/guest.c
> > +++ b/arch/arm64/kvm/guest.c
> > @@ -31,8 +31,6 @@
> > const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> > KVM_GENERIC_VM_STATS()
> > };
> > -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) =
> > - sizeof(struct kvm_vm_stat) / sizeof(u64));
> >
> > const struct kvm_stats_header kvm_vm_stats_header = {
> > .name_size = KVM_STATS_NAME_SIZE,
> > @@ -52,8 +50,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> > STATS_DESC_COUNTER(VCPU, mmio_exit_kernel),
> > STATS_DESC_COUNTER(VCPU, exits)
> > };
> > -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) =
> > - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
> >
> > const struct kvm_stats_header kvm_vcpu_stats_header = {
> > .name_size = KVM_STATS_NAME_SIZE,
> > diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
> > index af9dd029a4e1..75c6f264c626 100644
> > --- a/arch/mips/kvm/mips.c
> > +++ b/arch/mips/kvm/mips.c
> > @@ -41,8 +41,6 @@
> > const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> > KVM_GENERIC_VM_STATS()
> > };
> > -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) =
> > - sizeof(struct kvm_vm_stat) / sizeof(u64));
> >
> > const struct kvm_stats_header kvm_vm_stats_header = {
> > .name_size = KVM_STATS_NAME_SIZE,
> > @@ -85,8 +83,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> > STATS_DESC_COUNTER(VCPU, vz_cpucfg_exits),
> > #endif
> > };
> > -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) =
> > - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
> >
> > const struct kvm_stats_header kvm_vcpu_stats_header = {
> > .name_size = KVM_STATS_NAME_SIZE,
> > diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
> > index 79833f78d1da..5cc6e90095b0 100644
> > --- a/arch/powerpc/kvm/book3s.c
> > +++ b/arch/powerpc/kvm/book3s.c
> > @@ -43,8 +43,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> > STATS_DESC_ICOUNTER(VM, num_2M_pages),
> > STATS_DESC_ICOUNTER(VM, num_1G_pages)
> > };
> > -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) =
> > - sizeof(struct kvm_vm_stat) / sizeof(u64));
> >
> > const struct kvm_stats_header kvm_vm_stats_header = {
> > .name_size = KVM_STATS_NAME_SIZE,
> > @@ -88,8 +86,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> > STATS_DESC_COUNTER(VCPU, pthru_host),
> > STATS_DESC_COUNTER(VCPU, pthru_bad_aff)
> > };
> > -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) =
> > - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
> >
> > const struct kvm_stats_header kvm_vcpu_stats_header = {
> > .name_size = KVM_STATS_NAME_SIZE,
> > diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
> > index 551b30d84aee..5ed6c235e059 100644
> > --- a/arch/powerpc/kvm/booke.c
> > +++ b/arch/powerpc/kvm/booke.c
> > @@ -41,8 +41,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> > STATS_DESC_ICOUNTER(VM, num_2M_pages),
> > STATS_DESC_ICOUNTER(VM, num_1G_pages)
> > };
> > -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) =
> > - sizeof(struct kvm_vm_stat) / sizeof(u64));
> >
> > const struct kvm_stats_header kvm_vm_stats_header = {
> > .name_size = KVM_STATS_NAME_SIZE,
> > @@ -79,8 +77,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> > STATS_DESC_COUNTER(VCPU, pthru_host),
> > STATS_DESC_COUNTER(VCPU, pthru_bad_aff)
> > };
> > -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) =
> > - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
> >
> > const struct kvm_stats_header kvm_vcpu_stats_header = {
> > .name_size = KVM_STATS_NAME_SIZE,
> > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> > index 1695f0ced5ba..7610d33d319b 100644
> > --- a/arch/s390/kvm/kvm-s390.c
> > +++ b/arch/s390/kvm/kvm-s390.c
> > @@ -66,8 +66,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> > STATS_DESC_COUNTER(VM, inject_service_signal),
> > STATS_DESC_COUNTER(VM, inject_virtio)
> > };
> > -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) =
> > - sizeof(struct kvm_vm_stat) / sizeof(u64));
> >
> > const struct kvm_stats_header kvm_vm_stats_header = {
> > .name_size = KVM_STATS_NAME_SIZE,
> > @@ -174,8 +172,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> > STATS_DESC_COUNTER(VCPU, diagnose_other),
> > STATS_DESC_COUNTER(VCPU, pfault_sync)
> > };
> > -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) =
> > - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
> >
> > const struct kvm_stats_header kvm_vcpu_stats_header = {
> > .name_size = KVM_STATS_NAME_SIZE,
> > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> > index 8166ad113fb2..b94a80ad5b8d 100644
> > --- a/arch/x86/kvm/x86.c
> > +++ b/arch/x86/kvm/x86.c
> > @@ -239,8 +239,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> > STATS_DESC_ICOUNTER(VM, nx_lpage_splits),
> > STATS_DESC_PCOUNTER(VM, max_mmu_page_hash_collisions)
> > };
> > -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) =
> > - sizeof(struct kvm_vm_stat) / sizeof(u64));
> >
> > const struct kvm_stats_header kvm_vm_stats_header = {
> > .name_size = KVM_STATS_NAME_SIZE,
> > @@ -280,8 +278,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> > STATS_DESC_COUNTER(VCPU, directed_yield_successful),
> > STATS_DESC_ICOUNTER(VCPU, guest_mode)
> > };
> > -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) =
> > - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
> >
> > const struct kvm_stats_header kvm_vcpu_stats_header = {
> > .name_size = KVM_STATS_NAME_SIZE,
> > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> > index ae7735b490b4..356af173114d 100644
> > --- a/include/linux/kvm_host.h
> > +++ b/include/linux/kvm_host.h
> > @@ -1273,56 +1273,66 @@ struct _kvm_stats_desc {
> > char name[KVM_STATS_NAME_SIZE];
> > };
> >
> > -#define STATS_DESC_COMMON(type, unit, base, exp) \
> > +#define STATS_DESC_COMMON(type, unit, base, exp, sz, param) \
> > .flags = type | unit | base | \
> > BUILD_BUG_ON_ZERO(type & ~KVM_STATS_TYPE_MASK) | \
> > BUILD_BUG_ON_ZERO(unit & ~KVM_STATS_UNIT_MASK) | \
> > BUILD_BUG_ON_ZERO(base & ~KVM_STATS_BASE_MASK), \
> > .exponent = exp, \
> > - .size = 1
> > + .size = sz, \
> > + .hist_param = param
> >
> > -#define VM_GENERIC_STATS_DESC(stat, type, unit, base, exp) \
> > +#define VM_GENERIC_STATS_DESC(stat, type, unit, base, exp, sz, param) \
> > { \
> > { \
> > - STATS_DESC_COMMON(type, unit, base, exp), \
> > + STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
> > .offset = offsetof(struct kvm_vm_stat, generic.stat) \
> > }, \
> > .name = #stat, \
> > }
> > -#define VCPU_GENERIC_STATS_DESC(stat, type, unit, base, exp) \
> > +#define VCPU_GENERIC_STATS_DESC(stat, type, unit, base, exp, sz, param) \
> > { \
> > { \
> > - STATS_DESC_COMMON(type, unit, base, exp), \
> > + STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
> > .offset = offsetof(struct kvm_vcpu_stat, generic.stat) \
> > }, \
> > .name = #stat, \
> > }
> > -#define VM_STATS_DESC(stat, type, unit, base, exp) \
> > +#define VM_STATS_DESC(stat, type, unit, base, exp, sz, param) \
> > { \
> > { \
> > - STATS_DESC_COMMON(type, unit, base, exp), \
> > + STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
> > .offset = offsetof(struct kvm_vm_stat, stat) \
> > }, \
> > .name = #stat, \
> > }
> > -#define VCPU_STATS_DESC(stat, type, unit, base, exp) \
> > +#define VCPU_STATS_DESC(stat, type, unit, base, exp, sz, param) \
> > { \
> > { \
> > - STATS_DESC_COMMON(type, unit, base, exp), \
> > + STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
> > .offset = offsetof(struct kvm_vcpu_stat, stat) \
> > }, \
> > .name = #stat, \
> > }
> > /* SCOPE: VM, VM_GENERIC, VCPU, VCPU_GENERIC */
> > -#define STATS_DESC(SCOPE, stat, type, unit, base, exp) \
> > - SCOPE##_STATS_DESC(stat, type, unit, base, exp)
> > +#define STATS_DESC(SCOPE, stat, type, unit, base, exp, sz, param) \
> > + SCOPE##_STATS_DESC(stat, type, unit, base, exp, sz, param)
> >
> > #define STATS_DESC_CUMULATIVE(SCOPE, name, unit, base, exponent) \
> > - STATS_DESC(SCOPE, name, KVM_STATS_TYPE_CUMULATIVE, unit, base, exponent)
> > + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_CUMULATIVE, \
> > + unit, base, exponent, 1, 0)
> > #define STATS_DESC_INSTANT(SCOPE, name, unit, base, exponent) \
> > - STATS_DESC(SCOPE, name, KVM_STATS_TYPE_INSTANT, unit, base, exponent)
> > + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_INSTANT, \
> > + unit, base, exponent, 1, 0)
> > #define STATS_DESC_PEAK(SCOPE, name, unit, base, exponent) \
> > - STATS_DESC(SCOPE, name, KVM_STATS_TYPE_PEAK, unit, base, exponent)
> > + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_PEAK, \
> > + unit, base, exponent, 1, 0)
> > +#define STATS_DESC_LINEAR_HIST(SCOPE, name, unit, base, exponent, sz, param) \
> > + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_LINEAR_HIST, \
> > + unit, base, exponent, sz, param)
> > +#define STATS_DESC_LOG_HIST(SCOPE, name, unit, base, exponent, sz, param) \
> > + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_LOG_HIST, \
> > + unit, base, exponent, sz, param)
> >
> > /* Cumulative counter, read/write */
> > #define STATS_DESC_COUNTER(SCOPE, name) \
> > @@ -1341,6 +1351,14 @@ struct _kvm_stats_desc {
> > #define STATS_DESC_TIME_NSEC(SCOPE, name) \
> > STATS_DESC_CUMULATIVE(SCOPE, name, KVM_STATS_UNIT_SECONDS, \
> > KVM_STATS_BASE_POW10, -9)
> > +/* Linear histogram for time in nanosecond */
> > +#define STATS_DESC_LINHIST_TIME_NSEC(SCOPE, name, sz, bucket_size) \
> > + STATS_DESC_LINEAR_HIST(SCOPE, name, KVM_STATS_UNIT_SECONDS, \
> > + KVM_STATS_BASE_POW10, -9, sz, bucket_size)
> > +/* Logarithmic histogram for time in nanosecond */
> > +#define STATS_DESC_LOGHIST_TIME_NSEC(SCOPE, name, sz) \
> > + STATS_DESC_LOG_HIST(SCOPE, name, KVM_STATS_UNIT_SECONDS, \
> > + KVM_STATS_BASE_POW10, -9, sz, LOGHIST_BASE_2)
> >
> > #define KVM_GENERIC_VM_STATS() \
> > STATS_DESC_COUNTER(VM_GENERIC, remote_tlb_flush)
> > @@ -1354,10 +1372,15 @@ struct _kvm_stats_desc {
> > STATS_DESC_TIME_NSEC(VCPU_GENERIC, halt_poll_fail_ns)
> >
> > extern struct dentry *kvm_debugfs_dir;
> > +
> > ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header,
> > const struct _kvm_stats_desc *desc,
> > void *stats, size_t size_stats,
> > char __user *user_buffer, size_t size, loff_t *offset);
> > +void kvm_stats_linear_hist_update(u64 *data, size_t size,
> > + u64 value, size_t bucket_size);
> > +void kvm_stats_log_hist_update(u64 *data, size_t size, u64 value);
> > +
> > extern const struct kvm_stats_header kvm_vm_stats_header;
> > extern const struct _kvm_stats_desc kvm_vm_stats_desc[];
> > extern const struct kvm_stats_header kvm_vcpu_stats_header;
> > diff --git a/include/linux/kvm_types.h b/include/linux/kvm_types.h
> > index ed6a985c5680..cc88cd676775 100644
> > --- a/include/linux/kvm_types.h
> > +++ b/include/linux/kvm_types.h
> > @@ -76,6 +76,22 @@ struct kvm_mmu_memory_cache {
> > };
> > #endif
> >
> > +/* Constants used for histogram stats */
> > +#define LINHIST_SIZE_SMALL 10
> > +#define LINHIST_SIZE_MEDIUM 20
> > +#define LINHIST_SIZE_LARGE 50
> > +#define LINHIST_SIZE_XLARGE 100
>
> nit: s/SIZE/BUCKET_COUNT/
>
Sure, it makes more sense.
> > +#define LINHIST_BUCKET_SIZE_SMALL 10
> > +#define LINHIST_BUCKET_SIZE_MEDIUM 100
> > +#define LINHIST_BUCKET_SIZE_LARGE 1000
> > +#define LINHIST_BUCKET_SIZE_XLARGE 10000
> > +
> > +#define LOGHIST_SIZE_SMALL 8
> > +#define LOGHIST_SIZE_MEDIUM 16
> > +#define LOGHIST_SIZE_LARGE 32
> > +#define LOGHIST_SIZE_XLARGE 64
>
> Ditto here.
>
Will do.
> > +#define LOGHIST_BASE_2 2
> > +
> > struct kvm_vm_stat_generic {
> > u64 remote_tlb_flush;
> > };
> > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> > index 68c9e6d8bbda..ff34a471d9ef 100644
> > --- a/include/uapi/linux/kvm.h
> > +++ b/include/uapi/linux/kvm.h
> > @@ -1963,7 +1963,9 @@ struct kvm_stats_header {
> > #define KVM_STATS_TYPE_CUMULATIVE (0x0 << KVM_STATS_TYPE_SHIFT)
> > #define KVM_STATS_TYPE_INSTANT (0x1 << KVM_STATS_TYPE_SHIFT)
> > #define KVM_STATS_TYPE_PEAK (0x2 << KVM_STATS_TYPE_SHIFT)
> > -#define KVM_STATS_TYPE_MAX KVM_STATS_TYPE_PEAK
> > +#define KVM_STATS_TYPE_LINEAR_HIST (0x3 << KVM_STATS_TYPE_SHIFT)
> > +#define KVM_STATS_TYPE_LOG_HIST (0x4 << KVM_STATS_TYPE_SHIFT)
> > +#define KVM_STATS_TYPE_MAX KVM_STATS_TYPE_LOG_HIST
> >
> > #define KVM_STATS_UNIT_SHIFT 4
> > #define KVM_STATS_UNIT_MASK (0xF << KVM_STATS_UNIT_SHIFT)
> > @@ -1987,7 +1989,10 @@ struct kvm_stats_header {
> > * Every data item is of type __u64.
> > * @offset: The offset of the stats to the start of stat structure in
> > * struture kvm or kvm_vcpu.
> > - * @unused: Unused field for future usage. Always 0 for now.
> > + * @hist_param: A parameter value used for histogram stats. For linear
> > + * histogram stats, it indicates the size of the bucket;
> > + * For logarithmic histogram stats, it indicates the base
> > + * of the logarithm. Only base of 2 is supported.
> > * @name: The name string for the stats. Its size is indicated by the
> > * &kvm_stats_header->name_size.
> > */
> > @@ -1996,7 +2001,7 @@ struct kvm_stats_desc {
> > __s16 exponent;
> > __u16 size;
> > __u32 offset;
> > - __u32 unused;
> > + __u32 hist_param;
>
> `hist_param` is vague. What about making this an anonymous union to make
> the dual meaning explicit?
>
> union {
> /* Only used for KVM_STATS_TYPE_LOG_HIST. */
> __u32 base;
> /* Only used for KVM_STATS_TYPE_LINEAR_HIST. */
> __u32 bucket_size;
> };
>
> It may make the STATS_DESC code a bit more complicated but the rest of
> the code that uses it will be much more clear.
>
Since we only support base-2 log hist, maybe it is not necessary to
have the base field.
The reason to only support base-2 log hist is that its range is
already large enough for
any stats.
Will just change hist_param to bucket_size.
> > char name[];
> > };
> >
> > diff --git a/virt/kvm/binary_stats.c b/virt/kvm/binary_stats.c
> > index e609d428811a..6eead6979a7f 100644
> > --- a/virt/kvm/binary_stats.c
> > +++ b/virt/kvm/binary_stats.c
> > @@ -144,3 +144,39 @@ ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header,
> > *offset = pos;
> > return len;
> > }
> > +
> > +/**
> > + * kvm_stats_linear_hist_update() - Update bucket value for linear histogram
> > + * statistics data.
> > + *
> > + * @data: start address of the stats data
> > + * @size: the number of bucket of the stats data
> > + * @value: the new value used to update the linear histogram's bucket
> > + * @bucket_size: the size (width) of a bucket
> > + */
> > +void kvm_stats_linear_hist_update(u64 *data, size_t size,
> > + u64 value, size_t bucket_size)
> > +{
> > + size_t index = value / bucket_size;
> > +
> > + if (index >= size)
> > + index = size - 1;
>
> nit: It would be simpler to use max().
>
> size_t index = max(value / bucket_size, size - 1);
>
Will do.
> > + ++data[index];
> > +}
> > +
> > +/**
> > + * kvm_stats_log_hist_update() - Update bucket value for logarithmic histogram
> > + * statistics data.
> > + *
> > + * @data: start address of the stats data
> > + * @size: the number of bucket of the stats data
> > + * @value: the new value used to update the logarithmic histogram's bucket
> > + */
> > +void kvm_stats_log_hist_update(u64 *data, size_t size, u64 value)
> > +{
> > + size_t index = fls64(value);
> > +
> > + if (index >= size)
> > + index = size - 1;
>
> Ditto here about using max().
>
Will do.
> > + ++data[index];
> > +}
> > --
> > 2.32.0.93.g670b81a890-goog
> >
Thanks,
Jing
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v1 1/4] KVM: stats: Support linear and logarithmic histogram statistics
2021-07-08 21:40 ` Jing Zhang
@ 2021-07-08 21:45 ` David Matlack
-1 siblings, 0 replies; 22+ messages in thread
From: David Matlack @ 2021-07-08 21:45 UTC (permalink / raw)
To: Jing Zhang
Cc: KVM, KVMPPC, Paolo Bonzini, Sean Christopherson, Jim Mattson,
Peter Shier, Oliver Upton, David Rientjes
On Thu, Jul 08, 2021 at 04:40:16PM -0500, Jing Zhang wrote:
> On Thu, Jul 8, 2021 at 4:01 PM David Matlack <dmatlack@google.com> wrote:
> >
> > On Tue, Jul 06, 2021 at 06:03:47PM +0000, Jing Zhang wrote:
> > > Add new types of KVM stats, linear and logarithmic histogram.
> > > Histogram are very useful for observing the value distribution
> > > of time or size related stats.
> > >
> > > Signed-off-by: Jing Zhang <jingzhangos@google.com>
> > > ---
> > > arch/arm64/kvm/guest.c | 4 ---
> > > arch/mips/kvm/mips.c | 4 ---
> > > arch/powerpc/kvm/book3s.c | 4 ---
> > > arch/powerpc/kvm/booke.c | 4 ---
> > > arch/s390/kvm/kvm-s390.c | 4 ---
> > > arch/x86/kvm/x86.c | 4 ---
> > > include/linux/kvm_host.h | 53 ++++++++++++++++++++++++++++-----------
> > > include/linux/kvm_types.h | 16 ++++++++++++
> > > include/uapi/linux/kvm.h | 11 +++++---
> > > virt/kvm/binary_stats.c | 36 ++++++++++++++++++++++++++
> > > 10 files changed, 98 insertions(+), 42 deletions(-)
> > >
> > > diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
> > > index 1512a8007a78..cb44d8756fa7 100644
> > > --- a/arch/arm64/kvm/guest.c
> > > +++ b/arch/arm64/kvm/guest.c
> > > @@ -31,8 +31,6 @@
> > > const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> > > KVM_GENERIC_VM_STATS()
> > > };
> > > -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
> > > - sizeof(struct kvm_vm_stat) / sizeof(u64));
> > >
> > > const struct kvm_stats_header kvm_vm_stats_header = {
> > > .name_size = KVM_STATS_NAME_SIZE,
> > > @@ -52,8 +50,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> > > STATS_DESC_COUNTER(VCPU, mmio_exit_kernel),
> > > STATS_DESC_COUNTER(VCPU, exits)
> > > };
> > > -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) ==
> > > - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
> > >
> > > const struct kvm_stats_header kvm_vcpu_stats_header = {
> > > .name_size = KVM_STATS_NAME_SIZE,
> > > diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
> > > index af9dd029a4e1..75c6f264c626 100644
> > > --- a/arch/mips/kvm/mips.c
> > > +++ b/arch/mips/kvm/mips.c
> > > @@ -41,8 +41,6 @@
> > > const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> > > KVM_GENERIC_VM_STATS()
> > > };
> > > -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
> > > - sizeof(struct kvm_vm_stat) / sizeof(u64));
> > >
> > > const struct kvm_stats_header kvm_vm_stats_header = {
> > > .name_size = KVM_STATS_NAME_SIZE,
> > > @@ -85,8 +83,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> > > STATS_DESC_COUNTER(VCPU, vz_cpucfg_exits),
> > > #endif
> > > };
> > > -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) ==
> > > - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
> > >
> > > const struct kvm_stats_header kvm_vcpu_stats_header = {
> > > .name_size = KVM_STATS_NAME_SIZE,
> > > diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
> > > index 79833f78d1da..5cc6e90095b0 100644
> > > --- a/arch/powerpc/kvm/book3s.c
> > > +++ b/arch/powerpc/kvm/book3s.c
> > > @@ -43,8 +43,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> > > STATS_DESC_ICOUNTER(VM, num_2M_pages),
> > > STATS_DESC_ICOUNTER(VM, num_1G_pages)
> > > };
> > > -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
> > > - sizeof(struct kvm_vm_stat) / sizeof(u64));
> > >
> > > const struct kvm_stats_header kvm_vm_stats_header = {
> > > .name_size = KVM_STATS_NAME_SIZE,
> > > @@ -88,8 +86,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> > > STATS_DESC_COUNTER(VCPU, pthru_host),
> > > STATS_DESC_COUNTER(VCPU, pthru_bad_aff)
> > > };
> > > -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) ==
> > > - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
> > >
> > > const struct kvm_stats_header kvm_vcpu_stats_header = {
> > > .name_size = KVM_STATS_NAME_SIZE,
> > > diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
> > > index 551b30d84aee..5ed6c235e059 100644
> > > --- a/arch/powerpc/kvm/booke.c
> > > +++ b/arch/powerpc/kvm/booke.c
> > > @@ -41,8 +41,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> > > STATS_DESC_ICOUNTER(VM, num_2M_pages),
> > > STATS_DESC_ICOUNTER(VM, num_1G_pages)
> > > };
> > > -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
> > > - sizeof(struct kvm_vm_stat) / sizeof(u64));
> > >
> > > const struct kvm_stats_header kvm_vm_stats_header = {
> > > .name_size = KVM_STATS_NAME_SIZE,
> > > @@ -79,8 +77,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> > > STATS_DESC_COUNTER(VCPU, pthru_host),
> > > STATS_DESC_COUNTER(VCPU, pthru_bad_aff)
> > > };
> > > -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) ==
> > > - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
> > >
> > > const struct kvm_stats_header kvm_vcpu_stats_header = {
> > > .name_size = KVM_STATS_NAME_SIZE,
> > > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> > > index 1695f0ced5ba..7610d33d319b 100644
> > > --- a/arch/s390/kvm/kvm-s390.c
> > > +++ b/arch/s390/kvm/kvm-s390.c
> > > @@ -66,8 +66,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> > > STATS_DESC_COUNTER(VM, inject_service_signal),
> > > STATS_DESC_COUNTER(VM, inject_virtio)
> > > };
> > > -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
> > > - sizeof(struct kvm_vm_stat) / sizeof(u64));
> > >
> > > const struct kvm_stats_header kvm_vm_stats_header = {
> > > .name_size = KVM_STATS_NAME_SIZE,
> > > @@ -174,8 +172,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> > > STATS_DESC_COUNTER(VCPU, diagnose_other),
> > > STATS_DESC_COUNTER(VCPU, pfault_sync)
> > > };
> > > -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) ==
> > > - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
> > >
> > > const struct kvm_stats_header kvm_vcpu_stats_header = {
> > > .name_size = KVM_STATS_NAME_SIZE,
> > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> > > index 8166ad113fb2..b94a80ad5b8d 100644
> > > --- a/arch/x86/kvm/x86.c
> > > +++ b/arch/x86/kvm/x86.c
> > > @@ -239,8 +239,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> > > STATS_DESC_ICOUNTER(VM, nx_lpage_splits),
> > > STATS_DESC_PCOUNTER(VM, max_mmu_page_hash_collisions)
> > > };
> > > -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
> > > - sizeof(struct kvm_vm_stat) / sizeof(u64));
> > >
> > > const struct kvm_stats_header kvm_vm_stats_header = {
> > > .name_size = KVM_STATS_NAME_SIZE,
> > > @@ -280,8 +278,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> > > STATS_DESC_COUNTER(VCPU, directed_yield_successful),
> > > STATS_DESC_ICOUNTER(VCPU, guest_mode)
> > > };
> > > -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) ==
> > > - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
> > >
> > > const struct kvm_stats_header kvm_vcpu_stats_header = {
> > > .name_size = KVM_STATS_NAME_SIZE,
> > > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> > > index ae7735b490b4..356af173114d 100644
> > > --- a/include/linux/kvm_host.h
> > > +++ b/include/linux/kvm_host.h
> > > @@ -1273,56 +1273,66 @@ struct _kvm_stats_desc {
> > > char name[KVM_STATS_NAME_SIZE];
> > > };
> > >
> > > -#define STATS_DESC_COMMON(type, unit, base, exp) \
> > > +#define STATS_DESC_COMMON(type, unit, base, exp, sz, param) \
> > > .flags = type | unit | base | \
> > > BUILD_BUG_ON_ZERO(type & ~KVM_STATS_TYPE_MASK) | \
> > > BUILD_BUG_ON_ZERO(unit & ~KVM_STATS_UNIT_MASK) | \
> > > BUILD_BUG_ON_ZERO(base & ~KVM_STATS_BASE_MASK), \
> > > .exponent = exp, \
> > > - .size = 1
> > > + .size = sz, \
> > > + .hist_param = param
> > >
> > > -#define VM_GENERIC_STATS_DESC(stat, type, unit, base, exp) \
> > > +#define VM_GENERIC_STATS_DESC(stat, type, unit, base, exp, sz, param) \
> > > { \
> > > { \
> > > - STATS_DESC_COMMON(type, unit, base, exp), \
> > > + STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
> > > .offset = offsetof(struct kvm_vm_stat, generic.stat) \
> > > }, \
> > > .name = #stat, \
> > > }
> > > -#define VCPU_GENERIC_STATS_DESC(stat, type, unit, base, exp) \
> > > +#define VCPU_GENERIC_STATS_DESC(stat, type, unit, base, exp, sz, param) \
> > > { \
> > > { \
> > > - STATS_DESC_COMMON(type, unit, base, exp), \
> > > + STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
> > > .offset = offsetof(struct kvm_vcpu_stat, generic.stat) \
> > > }, \
> > > .name = #stat, \
> > > }
> > > -#define VM_STATS_DESC(stat, type, unit, base, exp) \
> > > +#define VM_STATS_DESC(stat, type, unit, base, exp, sz, param) \
> > > { \
> > > { \
> > > - STATS_DESC_COMMON(type, unit, base, exp), \
> > > + STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
> > > .offset = offsetof(struct kvm_vm_stat, stat) \
> > > }, \
> > > .name = #stat, \
> > > }
> > > -#define VCPU_STATS_DESC(stat, type, unit, base, exp) \
> > > +#define VCPU_STATS_DESC(stat, type, unit, base, exp, sz, param) \
> > > { \
> > > { \
> > > - STATS_DESC_COMMON(type, unit, base, exp), \
> > > + STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
> > > .offset = offsetof(struct kvm_vcpu_stat, stat) \
> > > }, \
> > > .name = #stat, \
> > > }
> > > /* SCOPE: VM, VM_GENERIC, VCPU, VCPU_GENERIC */
> > > -#define STATS_DESC(SCOPE, stat, type, unit, base, exp) \
> > > - SCOPE##_STATS_DESC(stat, type, unit, base, exp)
> > > +#define STATS_DESC(SCOPE, stat, type, unit, base, exp, sz, param) \
> > > + SCOPE##_STATS_DESC(stat, type, unit, base, exp, sz, param)
> > >
> > > #define STATS_DESC_CUMULATIVE(SCOPE, name, unit, base, exponent) \
> > > - STATS_DESC(SCOPE, name, KVM_STATS_TYPE_CUMULATIVE, unit, base, exponent)
> > > + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_CUMULATIVE, \
> > > + unit, base, exponent, 1, 0)
> > > #define STATS_DESC_INSTANT(SCOPE, name, unit, base, exponent) \
> > > - STATS_DESC(SCOPE, name, KVM_STATS_TYPE_INSTANT, unit, base, exponent)
> > > + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_INSTANT, \
> > > + unit, base, exponent, 1, 0)
> > > #define STATS_DESC_PEAK(SCOPE, name, unit, base, exponent) \
> > > - STATS_DESC(SCOPE, name, KVM_STATS_TYPE_PEAK, unit, base, exponent)
> > > + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_PEAK, \
> > > + unit, base, exponent, 1, 0)
> > > +#define STATS_DESC_LINEAR_HIST(SCOPE, name, unit, base, exponent, sz, param) \
> > > + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_LINEAR_HIST, \
> > > + unit, base, exponent, sz, param)
> > > +#define STATS_DESC_LOG_HIST(SCOPE, name, unit, base, exponent, sz, param) \
> > > + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_LOG_HIST, \
> > > + unit, base, exponent, sz, param)
> > >
> > > /* Cumulative counter, read/write */
> > > #define STATS_DESC_COUNTER(SCOPE, name) \
> > > @@ -1341,6 +1351,14 @@ struct _kvm_stats_desc {
> > > #define STATS_DESC_TIME_NSEC(SCOPE, name) \
> > > STATS_DESC_CUMULATIVE(SCOPE, name, KVM_STATS_UNIT_SECONDS, \
> > > KVM_STATS_BASE_POW10, -9)
> > > +/* Linear histogram for time in nanosecond */
> > > +#define STATS_DESC_LINHIST_TIME_NSEC(SCOPE, name, sz, bucket_size) \
> > > + STATS_DESC_LINEAR_HIST(SCOPE, name, KVM_STATS_UNIT_SECONDS, \
> > > + KVM_STATS_BASE_POW10, -9, sz, bucket_size)
> > > +/* Logarithmic histogram for time in nanosecond */
> > > +#define STATS_DESC_LOGHIST_TIME_NSEC(SCOPE, name, sz) \
> > > + STATS_DESC_LOG_HIST(SCOPE, name, KVM_STATS_UNIT_SECONDS, \
> > > + KVM_STATS_BASE_POW10, -9, sz, LOGHIST_BASE_2)
> > >
> > > #define KVM_GENERIC_VM_STATS() \
> > > STATS_DESC_COUNTER(VM_GENERIC, remote_tlb_flush)
> > > @@ -1354,10 +1372,15 @@ struct _kvm_stats_desc {
> > > STATS_DESC_TIME_NSEC(VCPU_GENERIC, halt_poll_fail_ns)
> > >
> > > extern struct dentry *kvm_debugfs_dir;
> > > +
> > > ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header,
> > > const struct _kvm_stats_desc *desc,
> > > void *stats, size_t size_stats,
> > > char __user *user_buffer, size_t size, loff_t *offset);
> > > +void kvm_stats_linear_hist_update(u64 *data, size_t size,
> > > + u64 value, size_t bucket_size);
> > > +void kvm_stats_log_hist_update(u64 *data, size_t size, u64 value);
> > > +
> > > extern const struct kvm_stats_header kvm_vm_stats_header;
> > > extern const struct _kvm_stats_desc kvm_vm_stats_desc[];
> > > extern const struct kvm_stats_header kvm_vcpu_stats_header;
> > > diff --git a/include/linux/kvm_types.h b/include/linux/kvm_types.h
> > > index ed6a985c5680..cc88cd676775 100644
> > > --- a/include/linux/kvm_types.h
> > > +++ b/include/linux/kvm_types.h
> > > @@ -76,6 +76,22 @@ struct kvm_mmu_memory_cache {
> > > };
> > > #endif
> > >
> > > +/* Constants used for histogram stats */
> > > +#define LINHIST_SIZE_SMALL 10
> > > +#define LINHIST_SIZE_MEDIUM 20
> > > +#define LINHIST_SIZE_LARGE 50
> > > +#define LINHIST_SIZE_XLARGE 100
> >
> > nit: s/SIZE/BUCKET_COUNT/
> >
> Sure, it makes more sense.
> > > +#define LINHIST_BUCKET_SIZE_SMALL 10
> > > +#define LINHIST_BUCKET_SIZE_MEDIUM 100
> > > +#define LINHIST_BUCKET_SIZE_LARGE 1000
> > > +#define LINHIST_BUCKET_SIZE_XLARGE 10000
> > > +
> > > +#define LOGHIST_SIZE_SMALL 8
> > > +#define LOGHIST_SIZE_MEDIUM 16
> > > +#define LOGHIST_SIZE_LARGE 32
> > > +#define LOGHIST_SIZE_XLARGE 64
> >
> > Ditto here.
> >
> Will do.
> > > +#define LOGHIST_BASE_2 2
> > > +
> > > struct kvm_vm_stat_generic {
> > > u64 remote_tlb_flush;
> > > };
> > > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> > > index 68c9e6d8bbda..ff34a471d9ef 100644
> > > --- a/include/uapi/linux/kvm.h
> > > +++ b/include/uapi/linux/kvm.h
> > > @@ -1963,7 +1963,9 @@ struct kvm_stats_header {
> > > #define KVM_STATS_TYPE_CUMULATIVE (0x0 << KVM_STATS_TYPE_SHIFT)
> > > #define KVM_STATS_TYPE_INSTANT (0x1 << KVM_STATS_TYPE_SHIFT)
> > > #define KVM_STATS_TYPE_PEAK (0x2 << KVM_STATS_TYPE_SHIFT)
> > > -#define KVM_STATS_TYPE_MAX KVM_STATS_TYPE_PEAK
> > > +#define KVM_STATS_TYPE_LINEAR_HIST (0x3 << KVM_STATS_TYPE_SHIFT)
> > > +#define KVM_STATS_TYPE_LOG_HIST (0x4 << KVM_STATS_TYPE_SHIFT)
> > > +#define KVM_STATS_TYPE_MAX KVM_STATS_TYPE_LOG_HIST
> > >
> > > #define KVM_STATS_UNIT_SHIFT 4
> > > #define KVM_STATS_UNIT_MASK (0xF << KVM_STATS_UNIT_SHIFT)
> > > @@ -1987,7 +1989,10 @@ struct kvm_stats_header {
> > > * Every data item is of type __u64.
> > > * @offset: The offset of the stats to the start of stat structure in
> > > * struture kvm or kvm_vcpu.
> > > - * @unused: Unused field for future usage. Always 0 for now.
> > > + * @hist_param: A parameter value used for histogram stats. For linear
> > > + * histogram stats, it indicates the size of the bucket;
> > > + * For logarithmic histogram stats, it indicates the base
> > > + * of the logarithm. Only base of 2 is supported.
> > > * @name: The name string for the stats. Its size is indicated by the
> > > * &kvm_stats_header->name_size.
> > > */
> > > @@ -1996,7 +2001,7 @@ struct kvm_stats_desc {
> > > __s16 exponent;
> > > __u16 size;
> > > __u32 offset;
> > > - __u32 unused;
> > > + __u32 hist_param;
> >
> > `hist_param` is vague. What about making this an anonymous union to make
> > the dual meaning explicit?
> >
> > union {
> > /* Only used for KVM_STATS_TYPE_LOG_HIST. */
> > __u32 base;
> > /* Only used for KVM_STATS_TYPE_LINEAR_HIST. */
> > __u32 bucket_size;
> > };
> >
> > It may make the STATS_DESC code a bit more complicated but the rest of
> > the code that uses it will be much more clear.
> >
> Since we only support base-2 log hist, maybe it is not necessary to
> have the base field.
> The reason to only support base-2 log hist is that its range is
> already large enough for
> any stats.
> Will just change hist_param to bucket_size.
Cool sounds good. We can always add a custom base in the future without
breaking userspace by adding the anonymous union and guarding it behind
the flag field.
> > > char name[];
> > > };
> > >
> > > diff --git a/virt/kvm/binary_stats.c b/virt/kvm/binary_stats.c
> > > index e609d428811a..6eead6979a7f 100644
> > > --- a/virt/kvm/binary_stats.c
> > > +++ b/virt/kvm/binary_stats.c
> > > @@ -144,3 +144,39 @@ ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header,
> > > *offset = pos;
> > > return len;
> > > }
> > > +
> > > +/**
> > > + * kvm_stats_linear_hist_update() - Update bucket value for linear histogram
> > > + * statistics data.
> > > + *
> > > + * @data: start address of the stats data
> > > + * @size: the number of bucket of the stats data
> > > + * @value: the new value used to update the linear histogram's bucket
> > > + * @bucket_size: the size (width) of a bucket
> > > + */
> > > +void kvm_stats_linear_hist_update(u64 *data, size_t size,
> > > + u64 value, size_t bucket_size)
> > > +{
> > > + size_t index = value / bucket_size;
> > > +
> > > + if (index >= size)
> > > + index = size - 1;
> >
> > nit: It would be simpler to use max().
> >
> > size_t index = max(value / bucket_size, size - 1);
> >
> Will do.
> > > + ++data[index];
> > > +}
> > > +
> > > +/**
> > > + * kvm_stats_log_hist_update() - Update bucket value for logarithmic histogram
> > > + * statistics data.
> > > + *
> > > + * @data: start address of the stats data
> > > + * @size: the number of bucket of the stats data
> > > + * @value: the new value used to update the logarithmic histogram's bucket
> > > + */
> > > +void kvm_stats_log_hist_update(u64 *data, size_t size, u64 value)
> > > +{
> > > + size_t index = fls64(value);
> > > +
> > > + if (index >= size)
> > > + index = size - 1;
> >
> > Ditto here about using max().
> >
> Will do.
> > > + ++data[index];
> > > +}
> > > --
> > > 2.32.0.93.g670b81a890-goog
> > >
> Thanks,
> Jing
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v1 1/4] KVM: stats: Support linear and logarithmic histogram statistics
@ 2021-07-08 21:45 ` David Matlack
0 siblings, 0 replies; 22+ messages in thread
From: David Matlack @ 2021-07-08 21:45 UTC (permalink / raw)
To: Jing Zhang
Cc: KVM, KVMPPC, Paolo Bonzini, Sean Christopherson, Jim Mattson,
Peter Shier, Oliver Upton, David Rientjes
On Thu, Jul 08, 2021 at 04:40:16PM -0500, Jing Zhang wrote:
> On Thu, Jul 8, 2021 at 4:01 PM David Matlack <dmatlack@google.com> wrote:
> >
> > On Tue, Jul 06, 2021 at 06:03:47PM +0000, Jing Zhang wrote:
> > > Add new types of KVM stats, linear and logarithmic histogram.
> > > Histogram are very useful for observing the value distribution
> > > of time or size related stats.
> > >
> > > Signed-off-by: Jing Zhang <jingzhangos@google.com>
> > > ---
> > > arch/arm64/kvm/guest.c | 4 ---
> > > arch/mips/kvm/mips.c | 4 ---
> > > arch/powerpc/kvm/book3s.c | 4 ---
> > > arch/powerpc/kvm/booke.c | 4 ---
> > > arch/s390/kvm/kvm-s390.c | 4 ---
> > > arch/x86/kvm/x86.c | 4 ---
> > > include/linux/kvm_host.h | 53 ++++++++++++++++++++++++++++-----------
> > > include/linux/kvm_types.h | 16 ++++++++++++
> > > include/uapi/linux/kvm.h | 11 +++++---
> > > virt/kvm/binary_stats.c | 36 ++++++++++++++++++++++++++
> > > 10 files changed, 98 insertions(+), 42 deletions(-)
> > >
> > > diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
> > > index 1512a8007a78..cb44d8756fa7 100644
> > > --- a/arch/arm64/kvm/guest.c
> > > +++ b/arch/arm64/kvm/guest.c
> > > @@ -31,8 +31,6 @@
> > > const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> > > KVM_GENERIC_VM_STATS()
> > > };
> > > -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) =
> > > - sizeof(struct kvm_vm_stat) / sizeof(u64));
> > >
> > > const struct kvm_stats_header kvm_vm_stats_header = {
> > > .name_size = KVM_STATS_NAME_SIZE,
> > > @@ -52,8 +50,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> > > STATS_DESC_COUNTER(VCPU, mmio_exit_kernel),
> > > STATS_DESC_COUNTER(VCPU, exits)
> > > };
> > > -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) =
> > > - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
> > >
> > > const struct kvm_stats_header kvm_vcpu_stats_header = {
> > > .name_size = KVM_STATS_NAME_SIZE,
> > > diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
> > > index af9dd029a4e1..75c6f264c626 100644
> > > --- a/arch/mips/kvm/mips.c
> > > +++ b/arch/mips/kvm/mips.c
> > > @@ -41,8 +41,6 @@
> > > const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> > > KVM_GENERIC_VM_STATS()
> > > };
> > > -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) =
> > > - sizeof(struct kvm_vm_stat) / sizeof(u64));
> > >
> > > const struct kvm_stats_header kvm_vm_stats_header = {
> > > .name_size = KVM_STATS_NAME_SIZE,
> > > @@ -85,8 +83,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> > > STATS_DESC_COUNTER(VCPU, vz_cpucfg_exits),
> > > #endif
> > > };
> > > -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) =
> > > - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
> > >
> > > const struct kvm_stats_header kvm_vcpu_stats_header = {
> > > .name_size = KVM_STATS_NAME_SIZE,
> > > diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
> > > index 79833f78d1da..5cc6e90095b0 100644
> > > --- a/arch/powerpc/kvm/book3s.c
> > > +++ b/arch/powerpc/kvm/book3s.c
> > > @@ -43,8 +43,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> > > STATS_DESC_ICOUNTER(VM, num_2M_pages),
> > > STATS_DESC_ICOUNTER(VM, num_1G_pages)
> > > };
> > > -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) =
> > > - sizeof(struct kvm_vm_stat) / sizeof(u64));
> > >
> > > const struct kvm_stats_header kvm_vm_stats_header = {
> > > .name_size = KVM_STATS_NAME_SIZE,
> > > @@ -88,8 +86,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> > > STATS_DESC_COUNTER(VCPU, pthru_host),
> > > STATS_DESC_COUNTER(VCPU, pthru_bad_aff)
> > > };
> > > -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) =
> > > - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
> > >
> > > const struct kvm_stats_header kvm_vcpu_stats_header = {
> > > .name_size = KVM_STATS_NAME_SIZE,
> > > diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
> > > index 551b30d84aee..5ed6c235e059 100644
> > > --- a/arch/powerpc/kvm/booke.c
> > > +++ b/arch/powerpc/kvm/booke.c
> > > @@ -41,8 +41,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> > > STATS_DESC_ICOUNTER(VM, num_2M_pages),
> > > STATS_DESC_ICOUNTER(VM, num_1G_pages)
> > > };
> > > -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) =
> > > - sizeof(struct kvm_vm_stat) / sizeof(u64));
> > >
> > > const struct kvm_stats_header kvm_vm_stats_header = {
> > > .name_size = KVM_STATS_NAME_SIZE,
> > > @@ -79,8 +77,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> > > STATS_DESC_COUNTER(VCPU, pthru_host),
> > > STATS_DESC_COUNTER(VCPU, pthru_bad_aff)
> > > };
> > > -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) =
> > > - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
> > >
> > > const struct kvm_stats_header kvm_vcpu_stats_header = {
> > > .name_size = KVM_STATS_NAME_SIZE,
> > > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> > > index 1695f0ced5ba..7610d33d319b 100644
> > > --- a/arch/s390/kvm/kvm-s390.c
> > > +++ b/arch/s390/kvm/kvm-s390.c
> > > @@ -66,8 +66,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> > > STATS_DESC_COUNTER(VM, inject_service_signal),
> > > STATS_DESC_COUNTER(VM, inject_virtio)
> > > };
> > > -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) =
> > > - sizeof(struct kvm_vm_stat) / sizeof(u64));
> > >
> > > const struct kvm_stats_header kvm_vm_stats_header = {
> > > .name_size = KVM_STATS_NAME_SIZE,
> > > @@ -174,8 +172,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> > > STATS_DESC_COUNTER(VCPU, diagnose_other),
> > > STATS_DESC_COUNTER(VCPU, pfault_sync)
> > > };
> > > -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) =
> > > - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
> > >
> > > const struct kvm_stats_header kvm_vcpu_stats_header = {
> > > .name_size = KVM_STATS_NAME_SIZE,
> > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> > > index 8166ad113fb2..b94a80ad5b8d 100644
> > > --- a/arch/x86/kvm/x86.c
> > > +++ b/arch/x86/kvm/x86.c
> > > @@ -239,8 +239,6 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> > > STATS_DESC_ICOUNTER(VM, nx_lpage_splits),
> > > STATS_DESC_PCOUNTER(VM, max_mmu_page_hash_collisions)
> > > };
> > > -static_assert(ARRAY_SIZE(kvm_vm_stats_desc) =
> > > - sizeof(struct kvm_vm_stat) / sizeof(u64));
> > >
> > > const struct kvm_stats_header kvm_vm_stats_header = {
> > > .name_size = KVM_STATS_NAME_SIZE,
> > > @@ -280,8 +278,6 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
> > > STATS_DESC_COUNTER(VCPU, directed_yield_successful),
> > > STATS_DESC_ICOUNTER(VCPU, guest_mode)
> > > };
> > > -static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) =
> > > - sizeof(struct kvm_vcpu_stat) / sizeof(u64));
> > >
> > > const struct kvm_stats_header kvm_vcpu_stats_header = {
> > > .name_size = KVM_STATS_NAME_SIZE,
> > > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> > > index ae7735b490b4..356af173114d 100644
> > > --- a/include/linux/kvm_host.h
> > > +++ b/include/linux/kvm_host.h
> > > @@ -1273,56 +1273,66 @@ struct _kvm_stats_desc {
> > > char name[KVM_STATS_NAME_SIZE];
> > > };
> > >
> > > -#define STATS_DESC_COMMON(type, unit, base, exp) \
> > > +#define STATS_DESC_COMMON(type, unit, base, exp, sz, param) \
> > > .flags = type | unit | base | \
> > > BUILD_BUG_ON_ZERO(type & ~KVM_STATS_TYPE_MASK) | \
> > > BUILD_BUG_ON_ZERO(unit & ~KVM_STATS_UNIT_MASK) | \
> > > BUILD_BUG_ON_ZERO(base & ~KVM_STATS_BASE_MASK), \
> > > .exponent = exp, \
> > > - .size = 1
> > > + .size = sz, \
> > > + .hist_param = param
> > >
> > > -#define VM_GENERIC_STATS_DESC(stat, type, unit, base, exp) \
> > > +#define VM_GENERIC_STATS_DESC(stat, type, unit, base, exp, sz, param) \
> > > { \
> > > { \
> > > - STATS_DESC_COMMON(type, unit, base, exp), \
> > > + STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
> > > .offset = offsetof(struct kvm_vm_stat, generic.stat) \
> > > }, \
> > > .name = #stat, \
> > > }
> > > -#define VCPU_GENERIC_STATS_DESC(stat, type, unit, base, exp) \
> > > +#define VCPU_GENERIC_STATS_DESC(stat, type, unit, base, exp, sz, param) \
> > > { \
> > > { \
> > > - STATS_DESC_COMMON(type, unit, base, exp), \
> > > + STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
> > > .offset = offsetof(struct kvm_vcpu_stat, generic.stat) \
> > > }, \
> > > .name = #stat, \
> > > }
> > > -#define VM_STATS_DESC(stat, type, unit, base, exp) \
> > > +#define VM_STATS_DESC(stat, type, unit, base, exp, sz, param) \
> > > { \
> > > { \
> > > - STATS_DESC_COMMON(type, unit, base, exp), \
> > > + STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
> > > .offset = offsetof(struct kvm_vm_stat, stat) \
> > > }, \
> > > .name = #stat, \
> > > }
> > > -#define VCPU_STATS_DESC(stat, type, unit, base, exp) \
> > > +#define VCPU_STATS_DESC(stat, type, unit, base, exp, sz, param) \
> > > { \
> > > { \
> > > - STATS_DESC_COMMON(type, unit, base, exp), \
> > > + STATS_DESC_COMMON(type, unit, base, exp, sz, param), \
> > > .offset = offsetof(struct kvm_vcpu_stat, stat) \
> > > }, \
> > > .name = #stat, \
> > > }
> > > /* SCOPE: VM, VM_GENERIC, VCPU, VCPU_GENERIC */
> > > -#define STATS_DESC(SCOPE, stat, type, unit, base, exp) \
> > > - SCOPE##_STATS_DESC(stat, type, unit, base, exp)
> > > +#define STATS_DESC(SCOPE, stat, type, unit, base, exp, sz, param) \
> > > + SCOPE##_STATS_DESC(stat, type, unit, base, exp, sz, param)
> > >
> > > #define STATS_DESC_CUMULATIVE(SCOPE, name, unit, base, exponent) \
> > > - STATS_DESC(SCOPE, name, KVM_STATS_TYPE_CUMULATIVE, unit, base, exponent)
> > > + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_CUMULATIVE, \
> > > + unit, base, exponent, 1, 0)
> > > #define STATS_DESC_INSTANT(SCOPE, name, unit, base, exponent) \
> > > - STATS_DESC(SCOPE, name, KVM_STATS_TYPE_INSTANT, unit, base, exponent)
> > > + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_INSTANT, \
> > > + unit, base, exponent, 1, 0)
> > > #define STATS_DESC_PEAK(SCOPE, name, unit, base, exponent) \
> > > - STATS_DESC(SCOPE, name, KVM_STATS_TYPE_PEAK, unit, base, exponent)
> > > + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_PEAK, \
> > > + unit, base, exponent, 1, 0)
> > > +#define STATS_DESC_LINEAR_HIST(SCOPE, name, unit, base, exponent, sz, param) \
> > > + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_LINEAR_HIST, \
> > > + unit, base, exponent, sz, param)
> > > +#define STATS_DESC_LOG_HIST(SCOPE, name, unit, base, exponent, sz, param) \
> > > + STATS_DESC(SCOPE, name, KVM_STATS_TYPE_LOG_HIST, \
> > > + unit, base, exponent, sz, param)
> > >
> > > /* Cumulative counter, read/write */
> > > #define STATS_DESC_COUNTER(SCOPE, name) \
> > > @@ -1341,6 +1351,14 @@ struct _kvm_stats_desc {
> > > #define STATS_DESC_TIME_NSEC(SCOPE, name) \
> > > STATS_DESC_CUMULATIVE(SCOPE, name, KVM_STATS_UNIT_SECONDS, \
> > > KVM_STATS_BASE_POW10, -9)
> > > +/* Linear histogram for time in nanosecond */
> > > +#define STATS_DESC_LINHIST_TIME_NSEC(SCOPE, name, sz, bucket_size) \
> > > + STATS_DESC_LINEAR_HIST(SCOPE, name, KVM_STATS_UNIT_SECONDS, \
> > > + KVM_STATS_BASE_POW10, -9, sz, bucket_size)
> > > +/* Logarithmic histogram for time in nanosecond */
> > > +#define STATS_DESC_LOGHIST_TIME_NSEC(SCOPE, name, sz) \
> > > + STATS_DESC_LOG_HIST(SCOPE, name, KVM_STATS_UNIT_SECONDS, \
> > > + KVM_STATS_BASE_POW10, -9, sz, LOGHIST_BASE_2)
> > >
> > > #define KVM_GENERIC_VM_STATS() \
> > > STATS_DESC_COUNTER(VM_GENERIC, remote_tlb_flush)
> > > @@ -1354,10 +1372,15 @@ struct _kvm_stats_desc {
> > > STATS_DESC_TIME_NSEC(VCPU_GENERIC, halt_poll_fail_ns)
> > >
> > > extern struct dentry *kvm_debugfs_dir;
> > > +
> > > ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header,
> > > const struct _kvm_stats_desc *desc,
> > > void *stats, size_t size_stats,
> > > char __user *user_buffer, size_t size, loff_t *offset);
> > > +void kvm_stats_linear_hist_update(u64 *data, size_t size,
> > > + u64 value, size_t bucket_size);
> > > +void kvm_stats_log_hist_update(u64 *data, size_t size, u64 value);
> > > +
> > > extern const struct kvm_stats_header kvm_vm_stats_header;
> > > extern const struct _kvm_stats_desc kvm_vm_stats_desc[];
> > > extern const struct kvm_stats_header kvm_vcpu_stats_header;
> > > diff --git a/include/linux/kvm_types.h b/include/linux/kvm_types.h
> > > index ed6a985c5680..cc88cd676775 100644
> > > --- a/include/linux/kvm_types.h
> > > +++ b/include/linux/kvm_types.h
> > > @@ -76,6 +76,22 @@ struct kvm_mmu_memory_cache {
> > > };
> > > #endif
> > >
> > > +/* Constants used for histogram stats */
> > > +#define LINHIST_SIZE_SMALL 10
> > > +#define LINHIST_SIZE_MEDIUM 20
> > > +#define LINHIST_SIZE_LARGE 50
> > > +#define LINHIST_SIZE_XLARGE 100
> >
> > nit: s/SIZE/BUCKET_COUNT/
> >
> Sure, it makes more sense.
> > > +#define LINHIST_BUCKET_SIZE_SMALL 10
> > > +#define LINHIST_BUCKET_SIZE_MEDIUM 100
> > > +#define LINHIST_BUCKET_SIZE_LARGE 1000
> > > +#define LINHIST_BUCKET_SIZE_XLARGE 10000
> > > +
> > > +#define LOGHIST_SIZE_SMALL 8
> > > +#define LOGHIST_SIZE_MEDIUM 16
> > > +#define LOGHIST_SIZE_LARGE 32
> > > +#define LOGHIST_SIZE_XLARGE 64
> >
> > Ditto here.
> >
> Will do.
> > > +#define LOGHIST_BASE_2 2
> > > +
> > > struct kvm_vm_stat_generic {
> > > u64 remote_tlb_flush;
> > > };
> > > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> > > index 68c9e6d8bbda..ff34a471d9ef 100644
> > > --- a/include/uapi/linux/kvm.h
> > > +++ b/include/uapi/linux/kvm.h
> > > @@ -1963,7 +1963,9 @@ struct kvm_stats_header {
> > > #define KVM_STATS_TYPE_CUMULATIVE (0x0 << KVM_STATS_TYPE_SHIFT)
> > > #define KVM_STATS_TYPE_INSTANT (0x1 << KVM_STATS_TYPE_SHIFT)
> > > #define KVM_STATS_TYPE_PEAK (0x2 << KVM_STATS_TYPE_SHIFT)
> > > -#define KVM_STATS_TYPE_MAX KVM_STATS_TYPE_PEAK
> > > +#define KVM_STATS_TYPE_LINEAR_HIST (0x3 << KVM_STATS_TYPE_SHIFT)
> > > +#define KVM_STATS_TYPE_LOG_HIST (0x4 << KVM_STATS_TYPE_SHIFT)
> > > +#define KVM_STATS_TYPE_MAX KVM_STATS_TYPE_LOG_HIST
> > >
> > > #define KVM_STATS_UNIT_SHIFT 4
> > > #define KVM_STATS_UNIT_MASK (0xF << KVM_STATS_UNIT_SHIFT)
> > > @@ -1987,7 +1989,10 @@ struct kvm_stats_header {
> > > * Every data item is of type __u64.
> > > * @offset: The offset of the stats to the start of stat structure in
> > > * struture kvm or kvm_vcpu.
> > > - * @unused: Unused field for future usage. Always 0 for now.
> > > + * @hist_param: A parameter value used for histogram stats. For linear
> > > + * histogram stats, it indicates the size of the bucket;
> > > + * For logarithmic histogram stats, it indicates the base
> > > + * of the logarithm. Only base of 2 is supported.
> > > * @name: The name string for the stats. Its size is indicated by the
> > > * &kvm_stats_header->name_size.
> > > */
> > > @@ -1996,7 +2001,7 @@ struct kvm_stats_desc {
> > > __s16 exponent;
> > > __u16 size;
> > > __u32 offset;
> > > - __u32 unused;
> > > + __u32 hist_param;
> >
> > `hist_param` is vague. What about making this an anonymous union to make
> > the dual meaning explicit?
> >
> > union {
> > /* Only used for KVM_STATS_TYPE_LOG_HIST. */
> > __u32 base;
> > /* Only used for KVM_STATS_TYPE_LINEAR_HIST. */
> > __u32 bucket_size;
> > };
> >
> > It may make the STATS_DESC code a bit more complicated but the rest of
> > the code that uses it will be much more clear.
> >
> Since we only support base-2 log hist, maybe it is not necessary to
> have the base field.
> The reason to only support base-2 log hist is that its range is
> already large enough for
> any stats.
> Will just change hist_param to bucket_size.
Cool sounds good. We can always add a custom base in the future without
breaking userspace by adding the anonymous union and guarding it behind
the flag field.
> > > char name[];
> > > };
> > >
> > > diff --git a/virt/kvm/binary_stats.c b/virt/kvm/binary_stats.c
> > > index e609d428811a..6eead6979a7f 100644
> > > --- a/virt/kvm/binary_stats.c
> > > +++ b/virt/kvm/binary_stats.c
> > > @@ -144,3 +144,39 @@ ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header,
> > > *offset = pos;
> > > return len;
> > > }
> > > +
> > > +/**
> > > + * kvm_stats_linear_hist_update() - Update bucket value for linear histogram
> > > + * statistics data.
> > > + *
> > > + * @data: start address of the stats data
> > > + * @size: the number of bucket of the stats data
> > > + * @value: the new value used to update the linear histogram's bucket
> > > + * @bucket_size: the size (width) of a bucket
> > > + */
> > > +void kvm_stats_linear_hist_update(u64 *data, size_t size,
> > > + u64 value, size_t bucket_size)
> > > +{
> > > + size_t index = value / bucket_size;
> > > +
> > > + if (index >= size)
> > > + index = size - 1;
> >
> > nit: It would be simpler to use max().
> >
> > size_t index = max(value / bucket_size, size - 1);
> >
> Will do.
> > > + ++data[index];
> > > +}
> > > +
> > > +/**
> > > + * kvm_stats_log_hist_update() - Update bucket value for logarithmic histogram
> > > + * statistics data.
> > > + *
> > > + * @data: start address of the stats data
> > > + * @size: the number of bucket of the stats data
> > > + * @value: the new value used to update the logarithmic histogram's bucket
> > > + */
> > > +void kvm_stats_log_hist_update(u64 *data, size_t size, u64 value)
> > > +{
> > > + size_t index = fls64(value);
> > > +
> > > + if (index >= size)
> > > + index = size - 1;
> >
> > Ditto here about using max().
> >
> Will do.
> > > + ++data[index];
> > > +}
> > > --
> > > 2.32.0.93.g670b81a890-goog
> > >
> Thanks,
> Jing
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v1 1/4] KVM: stats: Support linear and logarithmic histogram statistics
2021-07-06 18:03 ` Jing Zhang
(?)
@ 2021-07-12 14:10 ` kernel test robot
-1 siblings, 0 replies; 22+ messages in thread
From: kernel test robot @ 2021-07-12 14:10 UTC (permalink / raw)
To: Jing Zhang, KVM, KVMPPC, Paolo Bonzini, Sean Christopherson,
Jim Mattson, Peter Shier, Oliver Upton, David Rientjes,
David Matlack
Cc: kbuild-all, Jing Zhang
[-- Attachment #1: Type: text/plain, Size: 1325 bytes --]
Hi Jing,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on 7caa04b36f204a01dac65582b71d26d190a1e022]
url: https://github.com/0day-ci/linux/commits/Jing-Zhang/Linear-and-Logarithmic-histogram-statistics/20210707-020549
base: 7caa04b36f204a01dac65582b71d26d190a1e022
config: i386-randconfig-a005-20210712 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
# https://github.com/0day-ci/linux/commit/aba26c018828dadbff3f53e058c161fab2b09d35
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Jing-Zhang/Linear-and-Logarithmic-histogram-statistics/20210707-020549
git checkout aba26c018828dadbff3f53e058c161fab2b09d35
# save the attached .config to linux build tree
mkdir build_dir
make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
ld: arch/x86/../../virt/kvm/binary_stats.o: in function `kvm_stats_linear_hist_update':
>> binary_stats.c:(.text+0x1ac): undefined reference to `__udivdi3'
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 42864 bytes --]
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v1 1/4] KVM: stats: Support linear and logarithmic histogram statistics
@ 2021-07-12 14:10 ` kernel test robot
0 siblings, 0 replies; 22+ messages in thread
From: kernel test robot @ 2021-07-12 14:10 UTC (permalink / raw)
To: Jing Zhang, KVM, KVMPPC, Paolo Bonzini, Sean Christopherson,
Jim Mattson, Peter Shier, Oliver Upton, David Rientjes,
David Matlack
Cc: kbuild-all, Jing Zhang
[-- Attachment #1: Type: text/plain, Size: 1325 bytes --]
Hi Jing,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on 7caa04b36f204a01dac65582b71d26d190a1e022]
url: https://github.com/0day-ci/linux/commits/Jing-Zhang/Linear-and-Logarithmic-histogram-statistics/20210707-020549
base: 7caa04b36f204a01dac65582b71d26d190a1e022
config: i386-randconfig-a005-20210712 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
# https://github.com/0day-ci/linux/commit/aba26c018828dadbff3f53e058c161fab2b09d35
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Jing-Zhang/Linear-and-Logarithmic-histogram-statistics/20210707-020549
git checkout aba26c018828dadbff3f53e058c161fab2b09d35
# save the attached .config to linux build tree
mkdir build_dir
make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
ld: arch/x86/../../virt/kvm/binary_stats.o: in function `kvm_stats_linear_hist_update':
>> binary_stats.c:(.text+0x1ac): undefined reference to `__udivdi3'
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 42864 bytes --]
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v1 1/4] KVM: stats: Support linear and logarithmic histogram statistics
@ 2021-07-12 14:10 ` kernel test robot
0 siblings, 0 replies; 22+ messages in thread
From: kernel test robot @ 2021-07-12 14:10 UTC (permalink / raw)
To: kbuild-all
[-- Attachment #1: Type: text/plain, Size: 1357 bytes --]
Hi Jing,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on 7caa04b36f204a01dac65582b71d26d190a1e022]
url: https://github.com/0day-ci/linux/commits/Jing-Zhang/Linear-and-Logarithmic-histogram-statistics/20210707-020549
base: 7caa04b36f204a01dac65582b71d26d190a1e022
config: i386-randconfig-a005-20210712 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
# https://github.com/0day-ci/linux/commit/aba26c018828dadbff3f53e058c161fab2b09d35
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Jing-Zhang/Linear-and-Logarithmic-histogram-statistics/20210707-020549
git checkout aba26c018828dadbff3f53e058c161fab2b09d35
# save the attached .config to linux build tree
mkdir build_dir
make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
ld: arch/x86/../../virt/kvm/binary_stats.o: in function `kvm_stats_linear_hist_update':
>> binary_stats.c:(.text+0x1ac): undefined reference to `__udivdi3'
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org
[-- Attachment #2: config.gz --]
[-- Type: application/gzip, Size: 42864 bytes --]
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v1 1/4] KVM: stats: Support linear and logarithmic histogram statistics
2021-07-12 14:10 ` kernel test robot
(?)
@ 2021-07-12 16:16 ` Jing Zhang
-1 siblings, 0 replies; 22+ messages in thread
From: Jing Zhang @ 2021-07-12 16:16 UTC (permalink / raw)
To: kernel test robot
Cc: KVM, KVMPPC, Paolo Bonzini, Sean Christopherson, Jim Mattson,
Peter Shier, Oliver Upton, David Rientjes, David Matlack,
kbuild-all
On Mon, Jul 12, 2021 at 9:10 AM kernel test robot <lkp@intel.com> wrote:
>
> Hi Jing,
>
> Thank you for the patch! Yet something to improve:
>
> [auto build test ERROR on 7caa04b36f204a01dac65582b71d26d190a1e022]
>
> url: https://github.com/0day-ci/linux/commits/Jing-Zhang/Linear-and-Logarithmic-histogram-statistics/20210707-020549
> base: 7caa04b36f204a01dac65582b71d26d190a1e022
> config: i386-randconfig-a005-20210712 (attached as .config)
> compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
> reproduce (this is a W=1 build):
> # https://github.com/0day-ci/linux/commit/aba26c018828dadbff3f53e058c161fab2b09d35
> git remote add linux-review https://github.com/0day-ci/linux
> git fetch --no-tags linux-review Jing-Zhang/Linear-and-Logarithmic-histogram-statistics/20210707-020549
> git checkout aba26c018828dadbff3f53e058c161fab2b09d35
> # save the attached .config to linux build tree
> mkdir build_dir
> make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
>
> All errors (new ones prefixed by >>):
>
> ld: arch/x86/../../virt/kvm/binary_stats.o: in function `kvm_stats_linear_hist_update':
> >> binary_stats.c:(.text+0x1ac): undefined reference to `__udivdi3'
Will fix this.
>
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
Thanks,
Jing
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v1 1/4] KVM: stats: Support linear and logarithmic histogram statistics
@ 2021-07-12 16:16 ` Jing Zhang
0 siblings, 0 replies; 22+ messages in thread
From: Jing Zhang @ 2021-07-12 16:16 UTC (permalink / raw)
To: kernel test robot
Cc: KVM, KVMPPC, Paolo Bonzini, Sean Christopherson, Jim Mattson,
Peter Shier, Oliver Upton, David Rientjes, David Matlack,
kbuild-all
On Mon, Jul 12, 2021 at 9:10 AM kernel test robot <lkp@intel.com> wrote:
>
> Hi Jing,
>
> Thank you for the patch! Yet something to improve:
>
> [auto build test ERROR on 7caa04b36f204a01dac65582b71d26d190a1e022]
>
> url: https://github.com/0day-ci/linux/commits/Jing-Zhang/Linear-and-Logarithmic-histogram-statistics/20210707-020549
> base: 7caa04b36f204a01dac65582b71d26d190a1e022
> config: i386-randconfig-a005-20210712 (attached as .config)
> compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
> reproduce (this is a W=1 build):
> # https://github.com/0day-ci/linux/commit/aba26c018828dadbff3f53e058c161fab2b09d35
> git remote add linux-review https://github.com/0day-ci/linux
> git fetch --no-tags linux-review Jing-Zhang/Linear-and-Logarithmic-histogram-statistics/20210707-020549
> git checkout aba26c018828dadbff3f53e058c161fab2b09d35
> # save the attached .config to linux build tree
> mkdir build_dir
> make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
>
> All errors (new ones prefixed by >>):
>
> ld: arch/x86/../../virt/kvm/binary_stats.o: in function `kvm_stats_linear_hist_update':
> >> binary_stats.c:(.text+0x1ac): undefined reference to `__udivdi3'
Will fix this.
>
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
Thanks,
Jing
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v1 1/4] KVM: stats: Support linear and logarithmic histogram statistics
@ 2021-07-12 16:16 ` Jing Zhang
0 siblings, 0 replies; 22+ messages in thread
From: Jing Zhang @ 2021-07-12 16:16 UTC (permalink / raw)
To: kbuild-all
[-- Attachment #1: Type: text/plain, Size: 1516 bytes --]
On Mon, Jul 12, 2021 at 9:10 AM kernel test robot <lkp@intel.com> wrote:
>
> Hi Jing,
>
> Thank you for the patch! Yet something to improve:
>
> [auto build test ERROR on 7caa04b36f204a01dac65582b71d26d190a1e022]
>
> url: https://github.com/0day-ci/linux/commits/Jing-Zhang/Linear-and-Logarithmic-histogram-statistics/20210707-020549
> base: 7caa04b36f204a01dac65582b71d26d190a1e022
> config: i386-randconfig-a005-20210712 (attached as .config)
> compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
> reproduce (this is a W=1 build):
> # https://github.com/0day-ci/linux/commit/aba26c018828dadbff3f53e058c161fab2b09d35
> git remote add linux-review https://github.com/0day-ci/linux
> git fetch --no-tags linux-review Jing-Zhang/Linear-and-Logarithmic-histogram-statistics/20210707-020549
> git checkout aba26c018828dadbff3f53e058c161fab2b09d35
> # save the attached .config to linux build tree
> mkdir build_dir
> make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
>
> All errors (new ones prefixed by >>):
>
> ld: arch/x86/../../virt/kvm/binary_stats.o: in function `kvm_stats_linear_hist_update':
> >> binary_stats.c:(.text+0x1ac): undefined reference to `__udivdi3'
Will fix this.
>
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org
Thanks,
Jing
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v1 1/4] KVM: stats: Support linear and logarithmic histogram statistics
2021-07-06 18:03 ` Jing Zhang
(?)
@ 2021-07-12 18:53 ` kernel test robot
-1 siblings, 0 replies; 22+ messages in thread
From: kernel test robot @ 2021-07-12 18:53 UTC (permalink / raw)
To: Jing Zhang, KVM, KVMPPC, Paolo Bonzini, Sean Christopherson,
Jim Mattson, Peter Shier, Oliver Upton, David Rientjes,
David Matlack
Cc: kbuild-all, Jing Zhang
[-- Attachment #1: Type: text/plain, Size: 1393 bytes --]
Hi Jing,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on 7caa04b36f204a01dac65582b71d26d190a1e022]
url: https://github.com/0day-ci/linux/commits/Jing-Zhang/Linear-and-Logarithmic-histogram-statistics/20210707-020549
base: 7caa04b36f204a01dac65582b71d26d190a1e022
config: mips-malta_kvm_defconfig (attached as .config)
compiler: mipsel-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/0day-ci/linux/commit/aba26c018828dadbff3f53e058c161fab2b09d35
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Jing-Zhang/Linear-and-Logarithmic-histogram-statistics/20210707-020549
git checkout aba26c018828dadbff3f53e058c161fab2b09d35
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=mips
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>, old ones prefixed by <<):
>> ERROR: modpost: "__udivdi3" [arch/mips/kvm/kvm.ko] undefined!
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 20937 bytes --]
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v1 1/4] KVM: stats: Support linear and logarithmic histogram statistics
@ 2021-07-12 18:53 ` kernel test robot
0 siblings, 0 replies; 22+ messages in thread
From: kernel test robot @ 2021-07-12 18:53 UTC (permalink / raw)
To: Jing Zhang, KVM, KVMPPC, Paolo Bonzini, Sean Christopherson,
Jim Mattson, Peter Shier, Oliver Upton, David Rientjes,
David Matlack
Cc: kbuild-all, Jing Zhang
[-- Attachment #1: Type: text/plain, Size: 1393 bytes --]
Hi Jing,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on 7caa04b36f204a01dac65582b71d26d190a1e022]
url: https://github.com/0day-ci/linux/commits/Jing-Zhang/Linear-and-Logarithmic-histogram-statistics/20210707-020549
base: 7caa04b36f204a01dac65582b71d26d190a1e022
config: mips-malta_kvm_defconfig (attached as .config)
compiler: mipsel-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/0day-ci/linux/commit/aba26c018828dadbff3f53e058c161fab2b09d35
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Jing-Zhang/Linear-and-Logarithmic-histogram-statistics/20210707-020549
git checkout aba26c018828dadbff3f53e058c161fab2b09d35
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=mips
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>, old ones prefixed by <<):
>> ERROR: modpost: "__udivdi3" [arch/mips/kvm/kvm.ko] undefined!
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 20937 bytes --]
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v1 1/4] KVM: stats: Support linear and logarithmic histogram statistics
@ 2021-07-12 18:53 ` kernel test robot
0 siblings, 0 replies; 22+ messages in thread
From: kernel test robot @ 2021-07-12 18:53 UTC (permalink / raw)
To: kbuild-all
[-- Attachment #1: Type: text/plain, Size: 1425 bytes --]
Hi Jing,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on 7caa04b36f204a01dac65582b71d26d190a1e022]
url: https://github.com/0day-ci/linux/commits/Jing-Zhang/Linear-and-Logarithmic-histogram-statistics/20210707-020549
base: 7caa04b36f204a01dac65582b71d26d190a1e022
config: mips-malta_kvm_defconfig (attached as .config)
compiler: mipsel-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/0day-ci/linux/commit/aba26c018828dadbff3f53e058c161fab2b09d35
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Jing-Zhang/Linear-and-Logarithmic-histogram-statistics/20210707-020549
git checkout aba26c018828dadbff3f53e058c161fab2b09d35
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=mips
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>, old ones prefixed by <<):
>> ERROR: modpost: "__udivdi3" [arch/mips/kvm/kvm.ko] undefined!
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org
[-- Attachment #2: config.gz --]
[-- Type: application/gzip, Size: 20937 bytes --]
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v1 1/4] KVM: stats: Support linear and logarithmic histogram statistics
2021-07-06 18:03 ` Jing Zhang
@ 2021-07-28 12:39 ` Paolo Bonzini
-1 siblings, 0 replies; 22+ messages in thread
From: Paolo Bonzini @ 2021-07-28 12:39 UTC (permalink / raw)
To: Jing Zhang, KVM, KVMPPC, Sean Christopherson, Jim Mattson,
Peter Shier, Oliver Upton, David Rientjes, David Matlack
On 06/07/21 20:03, Jing Zhang wrote:
> +#define LINHIST_SIZE_SMALL 10
> +#define LINHIST_SIZE_MEDIUM 20
> +#define LINHIST_SIZE_LARGE 50
> +#define LINHIST_SIZE_XLARGE 100
> +#define LINHIST_BUCKET_SIZE_SMALL 10
> +#define LINHIST_BUCKET_SIZE_MEDIUM 100
> +#define LINHIST_BUCKET_SIZE_LARGE 1000
> +#define LINHIST_BUCKET_SIZE_XLARGE 10000
> +
> +#define LOGHIST_SIZE_SMALL 8
> +#define LOGHIST_SIZE_MEDIUM 16
> +#define LOGHIST_SIZE_LARGE 32
> +#define LOGHIST_SIZE_XLARGE 64
> +#define LOGHIST_BASE_2 2
I'd prefer inlining all of these. For log histograms use 2 directly in
STATS_DESC_LOG_HIST, since the update function below uses fls64.
>
> + */
> +void kvm_stats_linear_hist_update(u64 *data, size_t size,
> + u64 value, size_t bucket_size)
> +{
> + size_t index = value / bucket_size;
> +
> + if (index >= size)
> + index = size - 1;
> + ++data[index];
> +}
> +
Please make this function always inline, so that the compiler optimizes
the division.
Also please use array_index_nospec to clamp the index to the size, in
case value comes from a memory access as well. Likewise for
kvm_stats_log_hist_update.
Paolo
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v1 1/4] KVM: stats: Support linear and logarithmic histogram statistics
@ 2021-07-28 12:39 ` Paolo Bonzini
0 siblings, 0 replies; 22+ messages in thread
From: Paolo Bonzini @ 2021-07-28 12:39 UTC (permalink / raw)
To: Jing Zhang, KVM, KVMPPC, Sean Christopherson, Jim Mattson,
Peter Shier, Oliver Upton, David Rientjes, David Matlack
On 06/07/21 20:03, Jing Zhang wrote:
> +#define LINHIST_SIZE_SMALL 10
> +#define LINHIST_SIZE_MEDIUM 20
> +#define LINHIST_SIZE_LARGE 50
> +#define LINHIST_SIZE_XLARGE 100
> +#define LINHIST_BUCKET_SIZE_SMALL 10
> +#define LINHIST_BUCKET_SIZE_MEDIUM 100
> +#define LINHIST_BUCKET_SIZE_LARGE 1000
> +#define LINHIST_BUCKET_SIZE_XLARGE 10000
> +
> +#define LOGHIST_SIZE_SMALL 8
> +#define LOGHIST_SIZE_MEDIUM 16
> +#define LOGHIST_SIZE_LARGE 32
> +#define LOGHIST_SIZE_XLARGE 64
> +#define LOGHIST_BASE_2 2
I'd prefer inlining all of these. For log histograms use 2 directly in
STATS_DESC_LOG_HIST, since the update function below uses fls64.
>
> + */
> +void kvm_stats_linear_hist_update(u64 *data, size_t size,
> + u64 value, size_t bucket_size)
> +{
> + size_t index = value / bucket_size;
> +
> + if (index >= size)
> + index = size - 1;
> + ++data[index];
> +}
> +
Please make this function always inline, so that the compiler optimizes
the division.
Also please use array_index_nospec to clamp the index to the size, in
case value comes from a memory access as well. Likewise for
kvm_stats_log_hist_update.
Paolo
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v1 1/4] KVM: stats: Support linear and logarithmic histogram statistics
2021-07-28 12:39 ` Paolo Bonzini
@ 2021-07-30 17:31 ` Jing Zhang
-1 siblings, 0 replies; 22+ messages in thread
From: Jing Zhang @ 2021-07-30 17:31 UTC (permalink / raw)
To: Paolo Bonzini
Cc: KVM, KVMPPC, Sean Christopherson, Jim Mattson, Peter Shier,
Oliver Upton, David Rientjes, David Matlack
On Wed, Jul 28, 2021 at 5:39 AM Paolo Bonzini <pbonzini@redhat.com> wrote:
>
> On 06/07/21 20:03, Jing Zhang wrote:
> > +#define LINHIST_SIZE_SMALL 10
> > +#define LINHIST_SIZE_MEDIUM 20
> > +#define LINHIST_SIZE_LARGE 50
> > +#define LINHIST_SIZE_XLARGE 100
> > +#define LINHIST_BUCKET_SIZE_SMALL 10
> > +#define LINHIST_BUCKET_SIZE_MEDIUM 100
> > +#define LINHIST_BUCKET_SIZE_LARGE 1000
> > +#define LINHIST_BUCKET_SIZE_XLARGE 10000
> > +
> > +#define LOGHIST_SIZE_SMALL 8
> > +#define LOGHIST_SIZE_MEDIUM 16
> > +#define LOGHIST_SIZE_LARGE 32
> > +#define LOGHIST_SIZE_XLARGE 64
> > +#define LOGHIST_BASE_2 2
>
> I'd prefer inlining all of these. For log histograms use 2 directly in
> STATS_DESC_LOG_HIST, since the update function below uses fls64.
>
Sure, will inline these values.
Will remove the loghist base, since base 2 log is enough for any
number. No other base is needed.
> >
> > + */
> > +void kvm_stats_linear_hist_update(u64 *data, size_t size,
> > + u64 value, size_t bucket_size)
> > +{
> > + size_t index = value / bucket_size;
> > +
> > + if (index >= size)
> > + index = size - 1;
> > + ++data[index];
> > +}
> > +
>
> Please make this function always inline, so that the compiler optimizes
> the division.
Sure.
>
> Also please use array_index_nospec to clamp the index to the size, in
> case value comes from a memory access as well. Likewise for
> kvm_stats_log_hist_update.
Thanks. Will do.
>
> Paolo
>
Jing
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v1 1/4] KVM: stats: Support linear and logarithmic histogram statistics
@ 2021-07-30 17:31 ` Jing Zhang
0 siblings, 0 replies; 22+ messages in thread
From: Jing Zhang @ 2021-07-30 17:31 UTC (permalink / raw)
To: Paolo Bonzini
Cc: KVM, KVMPPC, Sean Christopherson, Jim Mattson, Peter Shier,
Oliver Upton, David Rientjes, David Matlack
On Wed, Jul 28, 2021 at 5:39 AM Paolo Bonzini <pbonzini@redhat.com> wrote:
>
> On 06/07/21 20:03, Jing Zhang wrote:
> > +#define LINHIST_SIZE_SMALL 10
> > +#define LINHIST_SIZE_MEDIUM 20
> > +#define LINHIST_SIZE_LARGE 50
> > +#define LINHIST_SIZE_XLARGE 100
> > +#define LINHIST_BUCKET_SIZE_SMALL 10
> > +#define LINHIST_BUCKET_SIZE_MEDIUM 100
> > +#define LINHIST_BUCKET_SIZE_LARGE 1000
> > +#define LINHIST_BUCKET_SIZE_XLARGE 10000
> > +
> > +#define LOGHIST_SIZE_SMALL 8
> > +#define LOGHIST_SIZE_MEDIUM 16
> > +#define LOGHIST_SIZE_LARGE 32
> > +#define LOGHIST_SIZE_XLARGE 64
> > +#define LOGHIST_BASE_2 2
>
> I'd prefer inlining all of these. For log histograms use 2 directly in
> STATS_DESC_LOG_HIST, since the update function below uses fls64.
>
Sure, will inline these values.
Will remove the loghist base, since base 2 log is enough for any
number. No other base is needed.
> >
> > + */
> > +void kvm_stats_linear_hist_update(u64 *data, size_t size,
> > + u64 value, size_t bucket_size)
> > +{
> > + size_t index = value / bucket_size;
> > +
> > + if (index >= size)
> > + index = size - 1;
> > + ++data[index];
> > +}
> > +
>
> Please make this function always inline, so that the compiler optimizes
> the division.
Sure.
>
> Also please use array_index_nospec to clamp the index to the size, in
> case value comes from a memory access as well. Likewise for
> kvm_stats_log_hist_update.
Thanks. Will do.
>
> Paolo
>
Jing
^ permalink raw reply [flat|nested] 22+ messages in thread