From: James Morse <james.morse@arm.com>
To: x86@kernel.org, linux-kernel@vger.kernel.org
Cc: Fenghua Yu <fenghua.yu@intel.com>,
Reinette Chatre <reinette.chatre@intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
H Peter Anvin <hpa@zytor.com>, Babu Moger <Babu.Moger@amd.com>,
James Morse <james.morse@arm.com>,
shameerali.kolothum.thodi@huawei.com,
D Scott Phillips OS <scott@os.amperecomputing.com>,
carl@os.amperecomputing.com, lcherian@marvell.com,
bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com,
xingxin.hx@openanolis.org, baolin.wang@linux.alibaba.com,
Jamie Iles <quic_jiles@quicinc.com>,
Xin Hao <xhao@linux.alibaba.com>,
peternewman@google.com, dfustini@baylibre.com
Subject: [PATCH v5 15/24] x86/resctrl: Allow arch to allocate memory needed in resctrl_arch_rmid_read()
Date: Fri, 28 Jul 2023 16:42:45 +0000 [thread overview]
Message-ID: <20230728164254.27562-16-james.morse@arm.com> (raw)
In-Reply-To: <20230728164254.27562-1-james.morse@arm.com>
Depending on the number of monitors available, Arm's MPAM may need to
allocate a monitor prior to reading the counter value. Allocating a
contended resource may involve sleeping.
add_rmid_to_limbo() calls resctrl_arch_rmid_read() for multiple domains,
the allocation should be valid for all domains.
__check_limbo() and mon_event_count() each make multiple calls to
resctrl_arch_rmid_read(), to avoid extra work on contended systems,
the allocation should be valid for multiple invocations of
resctrl_arch_rmid_read().
Add arch hooks for this allocation, which need calling before
resctrl_arch_rmid_read(). The allocated monitor is passed to
resctrl_arch_rmid_read(), then freed again afterwards. The helper
can be called on any CPU, and can sleep.
Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Signed-off-by: James Morse <james.morse@arm.com>
---
Changes since v3:
* Expanded comment.
* Removed stray header include.
* Reworded commit message.
* Made ctx a void * instead of an int.
Changes since v4:
* Used IS_ERR() in more places.
---
arch/x86/include/asm/resctrl.h | 11 ++++++++++
arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 5 +++++
arch/x86/kernel/cpu/resctrl/internal.h | 1 +
arch/x86/kernel/cpu/resctrl/monitor.c | 25 ++++++++++++++++++++---
include/linux/resctrl.h | 5 ++++-
5 files changed, 43 insertions(+), 4 deletions(-)
diff --git a/arch/x86/include/asm/resctrl.h b/arch/x86/include/asm/resctrl.h
index 66d9e18cdc61..0986b5208d76 100644
--- a/arch/x86/include/asm/resctrl.h
+++ b/arch/x86/include/asm/resctrl.h
@@ -136,6 +136,17 @@ static inline u32 resctrl_arch_rmid_idx_encode(u32 ignored, u32 rmid)
return rmid;
}
+/* x86 can always read an rmid, nothing needs allocating */
+struct rdt_resource;
+static inline void *resctrl_arch_mon_ctx_alloc(struct rdt_resource *r, int evtid)
+{
+ might_sleep();
+ return NULL;
+};
+
+static inline void resctrl_arch_mon_ctx_free(struct rdt_resource *r, int evtid,
+ void *ctx) { };
+
void resctrl_cpu_detect(struct cpuinfo_x86 *c);
#else
diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
index bd263b9a0abd..55bad57a7bd5 100644
--- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
+++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
@@ -546,6 +546,9 @@ void mon_event_read(struct rmid_read *rr, struct rdt_resource *r,
rr->d = d;
rr->val = 0;
rr->first = first;
+ rr->arch_mon_ctx = resctrl_arch_mon_ctx_alloc(r, evtid);
+ if (IS_ERR(rr->arch_mon_ctx))
+ return;
cpu = cpumask_any_housekeeping(&d->cpu_mask);
@@ -559,6 +562,8 @@ void mon_event_read(struct rmid_read *rr, struct rdt_resource *r,
smp_call_function_any(&d->cpu_mask, mon_event_count, rr, 1);
else
smp_call_on_cpu(cpu, smp_mon_event_count, rr, false);
+
+ resctrl_arch_mon_ctx_free(r, evtid, rr->arch_mon_ctx);
}
int rdtgroup_mondata_show(struct seq_file *m, void *arg)
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 7012f42a82ee..45db51280ff4 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -136,6 +136,7 @@ struct rmid_read {
bool first;
int err;
u64 val;
+ void *arch_mon_ctx;
};
extern bool rdt_alloc_capable;
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index 08e3307863c3..5eed8d0cbf36 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -275,7 +275,7 @@ static u64 mbm_overflow_count(u64 prev_msr, u64 cur_msr, unsigned int width)
int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain *d,
u32 closid, u32 rmid, enum resctrl_event_id eventid,
- u64 *val)
+ u64 *val, void *ignored)
{
struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(d);
@@ -342,9 +342,14 @@ void __check_limbo(struct rdt_domain *d, bool force_free)
u32 idx_limit = resctrl_arch_system_num_rmid_idx();
struct rmid_entry *entry;
u32 idx, cur_idx = 1;
+ void *arch_mon_ctx;
bool rmid_dirty;
u64 val = 0;
+ arch_mon_ctx = resctrl_arch_mon_ctx_alloc(r, QOS_L3_OCCUP_EVENT_ID);
+ if (IS_ERR(arch_mon_ctx))
+ return;
+
/*
* Skip RMID 0 and start from RMID 1 and check all the RMIDs that
* are marked as busy for occupancy < threshold. If the occupancy
@@ -358,7 +363,8 @@ void __check_limbo(struct rdt_domain *d, bool force_free)
entry = __rmid_entry(idx);
if (resctrl_arch_rmid_read(r, d, entry->closid, entry->rmid,
- QOS_L3_OCCUP_EVENT_ID, &val)) {
+ QOS_L3_OCCUP_EVENT_ID, &val,
+ arch_mon_ctx)) {
rmid_dirty = true;
} else {
rmid_dirty = (val >= resctrl_rmid_realloc_threshold);
@@ -371,6 +377,8 @@ void __check_limbo(struct rdt_domain *d, bool force_free)
}
cur_idx = idx + 1;
}
+
+ resctrl_arch_mon_ctx_free(r, QOS_L3_OCCUP_EVENT_ID, arch_mon_ctx);
}
bool has_busy_rmid(struct rdt_domain *d)
@@ -544,7 +552,7 @@ static int __mon_event_count(u32 closid, u32 rmid, struct rmid_read *rr)
}
rr->err = resctrl_arch_rmid_read(rr->r, rr->d, closid, rmid, rr->evtid,
- &tval);
+ &tval, rr->arch_mon_ctx);
if (rr->err)
return rr->err;
@@ -754,11 +762,21 @@ static void mbm_update(struct rdt_resource *r, struct rdt_domain *d,
if (is_mbm_total_enabled()) {
rr.evtid = QOS_L3_MBM_TOTAL_EVENT_ID;
rr.val = 0;
+ rr.arch_mon_ctx = resctrl_arch_mon_ctx_alloc(rr.r, rr.evtid);
+ if (IS_ERR(rr.arch_mon_ctx))
+ return;
+
__mon_event_count(closid, rmid, &rr);
+
+ resctrl_arch_mon_ctx_free(rr.r, rr.evtid, rr.arch_mon_ctx);
}
if (is_mbm_local_enabled()) {
rr.evtid = QOS_L3_MBM_LOCAL_EVENT_ID;
rr.val = 0;
+ rr.arch_mon_ctx = resctrl_arch_mon_ctx_alloc(rr.r, rr.evtid);
+ if (IS_ERR(rr.arch_mon_ctx))
+ return;
+
__mon_event_count(closid, rmid, &rr);
/*
@@ -768,6 +786,7 @@ static void mbm_update(struct rdt_resource *r, struct rdt_domain *d,
*/
if (is_mba_sc(NULL))
mbm_bw_count(closid, rmid, &rr);
+ resctrl_arch_mon_ctx_free(rr.r, rr.evtid, rr.arch_mon_ctx);
}
}
diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index f7311102e94c..5e4b4df9610b 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -235,6 +235,9 @@ void resctrl_offline_domain(struct rdt_resource *r, struct rdt_domain *d);
* @rmid: rmid of the counter to read.
* @eventid: eventid to read, e.g. L3 occupancy.
* @val: result of the counter read in bytes.
+ * @arch_mon_ctx: An architecture specific value from
+ * resctrl_arch_mon_ctx_alloc(), for MPAM this identifies
+ * the hardware monitor allocated for this read request.
*
* Some architectures need to sleep when first programming some of the counters.
* (specifically: arm64's MPAM cache occupancy counters can return 'not ready'
@@ -248,7 +251,7 @@ void resctrl_offline_domain(struct rdt_resource *r, struct rdt_domain *d);
*/
int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain *d,
u32 closid, u32 rmid, enum resctrl_event_id eventid,
- u64 *val);
+ u64 *val, void *arch_mon_ctx);
/**
* resctrl_arch_rmid_read_context_check() - warn about invalid contexts
--
2.39.2
next prev parent reply other threads:[~2023-07-28 16:46 UTC|newest]
Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-28 16:42 [PATCH v5 00/24] x86/resctrl: monitored closid+rmid together, separate arch/fs locking James Morse
2023-07-28 16:42 ` [PATCH v5 01/24] x86/resctrl: Track the closid with the rmid James Morse
2023-08-09 22:32 ` Reinette Chatre
2023-08-24 16:50 ` James Morse
2023-08-15 0:09 ` Fenghua Yu
2023-07-28 16:42 ` [PATCH v5 02/24] x86/resctrl: Access per-rmid structures by index James Morse
2023-08-09 22:32 ` Reinette Chatre
2023-08-24 16:51 ` James Morse
2023-08-25 0:29 ` Reinette Chatre
2023-07-28 16:42 ` [PATCH v5 03/24] x86/resctrl: Create helper for RMID allocation and mondata dir creation James Morse
2023-08-09 22:32 ` Reinette Chatre
2023-07-28 16:42 ` [PATCH v5 04/24] x86/resctrl: Move rmid allocation out of mkdir_rdt_prepare() James Morse
2023-08-15 0:50 ` Fenghua Yu
2023-08-24 16:52 ` James Morse
2023-07-28 16:42 ` [PATCH v5 05/24] x86/resctrl: Allow RMID allocation to be scoped by CLOSID James Morse
2023-08-09 22:33 ` Reinette Chatre
2023-08-15 1:22 ` Fenghua Yu
2023-07-28 16:42 ` [PATCH v5 06/24] x86/resctrl: Track the number of dirty RMID a CLOSID has James Morse
2023-08-09 22:33 ` Reinette Chatre
2023-08-24 16:53 ` James Morse
2023-08-24 22:58 ` Reinette Chatre
2023-08-30 22:32 ` Tony Luck
2023-08-14 23:58 ` Fenghua Yu
2023-08-15 2:37 ` Fenghua Yu
2023-08-24 16:53 ` James Morse
2023-07-28 16:42 ` [PATCH v5 07/24] x86/resctrl: Use set_bit()/clear_bit() instead of open coding James Morse
2023-07-28 16:42 ` [PATCH v5 08/24] x86/resctrl: Allocate the cleanest CLOSID by searching closid_num_dirty_rmid James Morse
2023-08-15 2:59 ` Fenghua Yu
2023-08-24 16:54 ` James Morse
2023-07-28 16:42 ` [PATCH v5 09/24] x86/resctrl: Move CLOSID/RMID matching and setting to use helpers James Morse
2023-07-28 16:42 ` [PATCH v5 10/24] tick/nohz: Move tick_nohz_full_mask declaration outside the #ifdef James Morse
2023-08-09 22:34 ` Reinette Chatre
2023-08-24 16:55 ` James Morse
2023-08-25 0:43 ` Reinette Chatre
2023-09-08 15:58 ` James Morse
2023-07-28 16:42 ` [PATCH v5 11/24] x86/resctrl: Add cpumask_any_housekeeping() for limbo/overflow James Morse
2023-07-28 16:42 ` [PATCH v5 12/24] x86/resctrl: Make resctrl_arch_rmid_read() retry when it is interrupted James Morse
2023-08-09 22:35 ` Reinette Chatre
2023-08-24 16:55 ` James Morse
2023-08-24 23:01 ` Reinette Chatre
2023-09-08 15:58 ` James Morse
2023-09-08 20:15 ` Reinette Chatre
2023-07-28 16:42 ` [PATCH v5 13/24] x86/resctrl: Queue mon_event_read() instead of sending an IPI James Morse
2023-07-28 16:42 ` [PATCH v5 14/24] x86/resctrl: Allow resctrl_arch_rmid_read() to sleep James Morse
2023-08-09 22:36 ` Reinette Chatre
2023-08-24 16:56 ` James Morse
2023-08-24 23:02 ` Reinette Chatre
2023-09-08 15:58 ` James Morse
2023-09-08 20:15 ` Reinette Chatre
2023-07-28 16:42 ` James Morse [this message]
2023-08-09 22:37 ` [PATCH v5 15/24] x86/resctrl: Allow arch to allocate memory needed in resctrl_arch_rmid_read() Reinette Chatre
2023-08-24 16:56 ` James Morse
2023-08-24 23:04 ` Reinette Chatre
2023-09-15 17:37 ` James Morse
2023-07-28 16:42 ` [PATCH v5 16/24] x86/resctrl: Make resctrl_mounted checks explicit James Morse
2023-07-28 16:42 ` [PATCH v5 17/24] x86/resctrl: Move alloc/mon static keys into helpers James Morse
2023-07-28 16:42 ` [PATCH v5 18/24] x86/resctrl: Make rdt_enable_key the arch's decision to switch James Morse
2023-07-28 16:42 ` [PATCH v5 19/24] x86/resctrl: Add helpers for system wide mon/alloc capable James Morse
2023-08-17 18:34 ` Fenghua Yu
2023-08-24 16:57 ` James Morse
2023-07-28 16:42 ` [PATCH v5 20/24] x86/resctrl: Add cpu online callback for resctrl work James Morse
2023-08-09 22:38 ` Reinette Chatre
2023-07-28 16:42 ` [PATCH v5 21/24] x86/resctrl: Allow overflow/limbo handlers to be scheduled on any-but cpu James Morse
2023-08-09 22:38 ` Reinette Chatre
2023-08-24 16:57 ` James Morse
2023-07-28 16:42 ` [PATCH v5 22/24] x86/resctrl: Add cpu offline callback for resctrl work James Morse
2023-07-28 16:42 ` [PATCH v5 23/24] x86/resctrl: Move domain helper migration into resctrl_offline_cpu() James Morse
2023-08-09 22:39 ` Reinette Chatre
2023-07-28 16:42 ` [PATCH v5 24/24] x86/resctrl: Separate arch and fs resctrl locks James Morse
2023-08-09 22:41 ` Reinette Chatre
2023-08-24 16:57 ` James Morse
2023-08-18 22:05 ` Fenghua Yu
2023-08-24 16:58 ` James Morse
2023-08-03 7:34 ` [PATCH v5 00/24] x86/resctrl: monitored closid+rmid together, separate arch/fs locking Shaopeng Tan (Fujitsu)
2023-08-24 16:58 ` James Morse
2023-08-22 8:42 ` Peter Newman
2023-08-24 16:58 ` James Morse
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