* [Qemu-devel] [PATCH v3 0/3] memory: some little optimizations
@ 2016-05-12 10:07 Gonglei
2016-05-12 10:07 ` [Qemu-devel] [PATCH v3 1/3] memory: drop find_ram_block() Gonglei
` (2 more replies)
0 siblings, 3 replies; 5+ messages in thread
From: Gonglei @ 2016-05-12 10:07 UTC (permalink / raw)
To: qemu-devel; +Cc: pbonzini, famz, peter.huangpeng, Gonglei
Please see the details in each patch.
v3 -> v2:
- rebase on the master
- resend because Delivery has failed to these recipients or groups: qemu-devel@nongnu.org
v2 -> v1:
- rework an argument's name for clearity in patch 1. [Fam]
- fix some typos in patch 2. [Fam]
- touche block->fd directly and remove the wrappers. [Paolo]
Gonglei (3):
memory: drop find_ram_block()
exec: adjust rcu_read_lock requirement
memory: drop some wrappers that waste cpu cycle
Gonglei (3):
memory: drop find_ram_block()
exec: adjust rcu_read_lock requirement
memory: drop some wrappers that waste cpu cycle
exec.c | 71 ++++++-----------------------------------------
hw/misc/ivshmem.c | 8 ++++--
hw/virtio/vhost-user.c | 13 +++++----
include/exec/cpu-common.h | 4 +--
include/exec/ram_addr.h | 6 ++--
memory.c | 4 +--
migration/ram.c | 2 +-
migration/savevm.c | 4 +--
8 files changed, 31 insertions(+), 81 deletions(-)
--
1.7.12.4
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Qemu-devel] [PATCH v3 1/3] memory: drop find_ram_block()
2016-05-12 10:07 [Qemu-devel] [PATCH v3 0/3] memory: some little optimizations Gonglei
@ 2016-05-12 10:07 ` Gonglei
2016-05-12 10:07 ` [Qemu-devel] [PATCH v3 2/3] exec: adjust rcu_read_lock requirement Gonglei
2016-05-12 10:07 ` [Qemu-devel] [PATCH v3 3/3] memory: drop some wrappers that waste cpu cycle Gonglei
2 siblings, 0 replies; 5+ messages in thread
From: Gonglei @ 2016-05-12 10:07 UTC (permalink / raw)
To: qemu-devel; +Cc: pbonzini, famz, peter.huangpeng, Gonglei
On the one hand, we have already qemu_get_ram_block() whose function
is similar. On the other hand, we can directly use mr->ram_block but
searching RAMblock by ram_addr which is a kind of waste.
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
---
exec.c | 34 +++++++---------------------------
include/exec/cpu-common.h | 4 ++--
include/exec/ram_addr.h | 2 +-
memory.c | 2 +-
migration/ram.c | 2 +-
migration/savevm.c | 4 ++--
6 files changed, 14 insertions(+), 34 deletions(-)
diff --git a/exec.c b/exec.c
index c4f9036..c840bc7 100644
--- a/exec.c
+++ b/exec.c
@@ -1407,34 +1407,18 @@ static void qemu_ram_setup_dump(void *addr, ram_addr_t size)
}
}
-/* Called within an RCU critical section, or while the ramlist lock
- * is held.
- */
-static RAMBlock *find_ram_block(ram_addr_t addr)
-{
- RAMBlock *block;
-
- QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
- if (block->offset == addr) {
- return block;
- }
- }
-
- return NULL;
-}
-
const char *qemu_ram_get_idstr(RAMBlock *rb)
{
return rb->idstr;
}
/* Called with iothread lock held. */
-void qemu_ram_set_idstr(ram_addr_t addr, const char *name, DeviceState *dev)
+void qemu_ram_set_idstr(RAMBlock *new_block, const char *name, DeviceState *dev)
{
- RAMBlock *new_block, *block;
+ RAMBlock *block;
rcu_read_lock();
- new_block = find_ram_block(addr);
+
assert(new_block);
assert(!new_block->idstr[0]);
@@ -1448,7 +1432,8 @@ void qemu_ram_set_idstr(ram_addr_t addr, const char *name, DeviceState *dev)
pstrcat(new_block->idstr, sizeof(new_block->idstr), name);
QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
- if (block != new_block && !strcmp(block->idstr, new_block->idstr)) {
+ if (block != new_block &&
+ !strcmp(block->idstr, new_block->idstr)) {
fprintf(stderr, "RAMBlock \"%s\" already registered, abort!\n",
new_block->idstr);
abort();
@@ -1458,17 +1443,14 @@ void qemu_ram_set_idstr(ram_addr_t addr, const char *name, DeviceState *dev)
}
/* Called with iothread lock held. */
-void qemu_ram_unset_idstr(ram_addr_t addr)
+void qemu_ram_unset_idstr(RAMBlock *block)
{
- RAMBlock *block;
-
/* FIXME: arch_init.c assumes that this is not called throughout
* migration. Ignore the problem since hot-unplug during migration
* does not work anyway.
*/
rcu_read_lock();
- block = find_ram_block(addr);
if (block) {
memset(block->idstr, 0, sizeof(block->idstr));
}
@@ -1492,10 +1474,8 @@ static int memory_try_enable_merging(void *addr, size_t len)
* resize callback to update device state and/or add assertions to detect
* misuse, if necessary.
*/
-int qemu_ram_resize(ram_addr_t base, ram_addr_t newsize, Error **errp)
+int qemu_ram_resize(RAMBlock *block, ram_addr_t newsize, Error **errp)
{
- RAMBlock *block = find_ram_block(base);
-
assert(block);
newsize = HOST_PAGE_ALIGN(newsize);
diff --git a/include/exec/cpu-common.h b/include/exec/cpu-common.h
index 9e839e5..187df3b 100644
--- a/include/exec/cpu-common.h
+++ b/include/exec/cpu-common.h
@@ -65,8 +65,8 @@ MemoryRegion *qemu_ram_addr_from_host(void *ptr, ram_addr_t *ram_addr);
RAMBlock *qemu_ram_block_by_name(const char *name);
RAMBlock *qemu_ram_block_from_host(void *ptr, bool round_offset,
ram_addr_t *ram_addr, ram_addr_t *offset);
-void qemu_ram_set_idstr(ram_addr_t addr, const char *name, DeviceState *dev);
-void qemu_ram_unset_idstr(ram_addr_t addr);
+void qemu_ram_set_idstr(RAMBlock *block, const char *name, DeviceState *dev);
+void qemu_ram_unset_idstr(RAMBlock *block);
const char *qemu_ram_get_idstr(RAMBlock *rb);
void cpu_physical_memory_rw(hwaddr addr, uint8_t *buf,
diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index 5adf7a4..5b6e1b8 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -110,7 +110,7 @@ void qemu_set_ram_fd(ram_addr_t addr, int fd);
void *qemu_get_ram_block_host_ptr(ram_addr_t addr);
void qemu_ram_free(RAMBlock *block);
-int qemu_ram_resize(ram_addr_t base, ram_addr_t newsize, Error **errp);
+int qemu_ram_resize(RAMBlock *block, ram_addr_t newsize, Error **errp);
#define DIRTY_CLIENTS_ALL ((1 << DIRTY_MEMORY_NUM) - 1)
#define DIRTY_CLIENTS_NOCODE (DIRTY_CLIENTS_ALL & ~(1 << DIRTY_MEMORY_CODE))
diff --git a/memory.c b/memory.c
index f76f85d..239e6da 100644
--- a/memory.c
+++ b/memory.c
@@ -1671,7 +1671,7 @@ void memory_region_ram_resize(MemoryRegion *mr, ram_addr_t newsize, Error **errp
{
assert(mr->ram_block);
- qemu_ram_resize(memory_region_get_ram_addr(mr), newsize, errp);
+ qemu_ram_resize(mr->ram_block, newsize, errp);
}
static void memory_region_update_coalesced_range_as(MemoryRegion *mr, AddressSpace *as)
diff --git a/migration/ram.c b/migration/ram.c
index 3f05738..28b5dd8 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -2476,7 +2476,7 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
if (length != block->used_length) {
Error *local_err = NULL;
- ret = qemu_ram_resize(block->offset, length,
+ ret = qemu_ram_resize(block, length,
&local_err);
if (local_err) {
error_report_err(local_err);
diff --git a/migration/savevm.c b/migration/savevm.c
index 16ba443..3a2e843 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -2228,13 +2228,13 @@ void hmp_info_snapshots(Monitor *mon, const QDict *qdict)
void vmstate_register_ram(MemoryRegion *mr, DeviceState *dev)
{
- qemu_ram_set_idstr(memory_region_get_ram_addr(mr) & TARGET_PAGE_MASK,
+ qemu_ram_set_idstr(mr->ram_block,
memory_region_name(mr), dev);
}
void vmstate_unregister_ram(MemoryRegion *mr, DeviceState *dev)
{
- qemu_ram_unset_idstr(memory_region_get_ram_addr(mr) & TARGET_PAGE_MASK);
+ qemu_ram_unset_idstr(mr->ram_block);
}
void vmstate_register_ram_global(MemoryRegion *mr)
--
1.7.12.4
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [Qemu-devel] [PATCH v3 2/3] exec: adjust rcu_read_lock requirement
2016-05-12 10:07 [Qemu-devel] [PATCH v3 0/3] memory: some little optimizations Gonglei
2016-05-12 10:07 ` [Qemu-devel] [PATCH v3 1/3] memory: drop find_ram_block() Gonglei
@ 2016-05-12 10:07 ` Gonglei
2016-05-12 10:07 ` [Qemu-devel] [PATCH v3 3/3] memory: drop some wrappers that waste cpu cycle Gonglei
2 siblings, 0 replies; 5+ messages in thread
From: Gonglei @ 2016-05-12 10:07 UTC (permalink / raw)
To: qemu-devel; +Cc: pbonzini, famz, peter.huangpeng, Gonglei
qemu_ram_unset_idstr() doesn't need rcu lock anymore,
meanwhile make the range of rcu lock in
qemu_ram_set_idstr() as small as possible.
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
---
exec.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/exec.c b/exec.c
index c840bc7..117c9a8 100644
--- a/exec.c
+++ b/exec.c
@@ -1417,8 +1417,6 @@ void qemu_ram_set_idstr(RAMBlock *new_block, const char *name, DeviceState *dev)
{
RAMBlock *block;
- rcu_read_lock();
-
assert(new_block);
assert(!new_block->idstr[0]);
@@ -1431,6 +1429,7 @@ void qemu_ram_set_idstr(RAMBlock *new_block, const char *name, DeviceState *dev)
}
pstrcat(new_block->idstr, sizeof(new_block->idstr), name);
+ rcu_read_lock();
QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
if (block != new_block &&
!strcmp(block->idstr, new_block->idstr)) {
@@ -1449,12 +1448,9 @@ void qemu_ram_unset_idstr(RAMBlock *block)
* migration. Ignore the problem since hot-unplug during migration
* does not work anyway.
*/
-
- rcu_read_lock();
if (block) {
memset(block->idstr, 0, sizeof(block->idstr));
}
- rcu_read_unlock();
}
static int memory_try_enable_merging(void *addr, size_t len)
--
1.7.12.4
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [Qemu-devel] [PATCH v3 3/3] memory: drop some wrappers that waste cpu cycle
2016-05-12 10:07 [Qemu-devel] [PATCH v3 0/3] memory: some little optimizations Gonglei
2016-05-12 10:07 ` [Qemu-devel] [PATCH v3 1/3] memory: drop find_ram_block() Gonglei
2016-05-12 10:07 ` [Qemu-devel] [PATCH v3 2/3] exec: adjust rcu_read_lock requirement Gonglei
@ 2016-05-12 10:07 ` Gonglei
2016-05-17 1:50 ` Fam Zheng
2 siblings, 1 reply; 5+ messages in thread
From: Gonglei @ 2016-05-12 10:07 UTC (permalink / raw)
To: qemu-devel; +Cc: pbonzini, famz, peter.huangpeng, Gonglei
For better performance, we can use RAMblock
directly stored in memory_region at present.
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
---
exec.c | 33 ++-------------------------------
hw/misc/ivshmem.c | 8 +++++---
hw/virtio/vhost-user.c | 13 ++++++++-----
include/exec/ram_addr.h | 4 +---
memory.c | 2 +-
5 files changed, 17 insertions(+), 43 deletions(-)
diff --git a/exec.c b/exec.c
index 117c9a8..f8de928 100644
--- a/exec.c
+++ b/exec.c
@@ -1812,38 +1812,9 @@ void qemu_ram_remap(ram_addr_t addr, ram_addr_t length)
}
#endif /* !_WIN32 */
-int qemu_get_ram_fd(ram_addr_t addr)
+void *qemu_get_ram_block_host_ptr(RAMBlock *ram_block)
{
- RAMBlock *block;
- int fd;
-
- rcu_read_lock();
- block = qemu_get_ram_block(addr);
- fd = block->fd;
- rcu_read_unlock();
- return fd;
-}
-
-void qemu_set_ram_fd(ram_addr_t addr, int fd)
-{
- RAMBlock *block;
-
- rcu_read_lock();
- block = qemu_get_ram_block(addr);
- block->fd = fd;
- rcu_read_unlock();
-}
-
-void *qemu_get_ram_block_host_ptr(ram_addr_t addr)
-{
- RAMBlock *block;
- void *ptr;
-
- rcu_read_lock();
- block = qemu_get_ram_block(addr);
- ptr = ramblock_ptr(block, 0);
- rcu_read_unlock();
- return ptr;
+ return ramblock_ptr(ram_block, 0);
}
/* Return a host pointer to ram allocated with qemu_ram_alloc.
diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
index e40f23b..1e930fa 100644
--- a/hw/misc/ivshmem.c
+++ b/hw/misc/ivshmem.c
@@ -533,7 +533,9 @@ static void process_msg_shmem(IVShmemState *s, int fd, Error **errp)
}
memory_region_init_ram_ptr(&s->server_bar2, OBJECT(s),
"ivshmem.bar2", size, ptr);
- qemu_set_ram_fd(memory_region_get_ram_addr(&s->server_bar2), fd);
+ assert(s->server_bar2.ram_block);
+ s->server_bar2.ram_block->fd = fd;
+
s->ivshmem_bar2 = &s->server_bar2;
}
@@ -939,8 +941,8 @@ static void ivshmem_exit(PCIDevice *dev)
error_report("Failed to munmap shared memory %s",
strerror(errno));
}
-
- fd = qemu_get_ram_fd(memory_region_get_ram_addr(s->ivshmem_bar2));
+ assert(s->ivshmem_bar2->ram_block);
+ fd = s->ivshmem_bar2->ram_block->fd;
close(fd);
}
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index 5914e85..5082e04 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -248,17 +248,18 @@ static int vhost_user_set_mem_table(struct vhost_dev *dev,
for (i = 0; i < dev->mem->nregions; ++i) {
struct vhost_memory_region *reg = dev->mem->regions + i;
ram_addr_t ram_addr;
+ MemoryRegion *mr;
assert((uintptr_t)reg->userspace_addr == reg->userspace_addr);
- qemu_ram_addr_from_host((void *)(uintptr_t)reg->userspace_addr,
+ mr = qemu_ram_addr_from_host((void *)(uintptr_t)reg->userspace_addr,
&ram_addr);
- fd = qemu_get_ram_fd(ram_addr);
+ fd = mr->ram_block->fd;
if (fd > 0) {
msg.payload.memory.regions[fd_num].userspace_addr = reg->userspace_addr;
msg.payload.memory.regions[fd_num].memory_size = reg->memory_size;
msg.payload.memory.regions[fd_num].guest_phys_addr = reg->guest_phys_addr;
msg.payload.memory.regions[fd_num].mmap_offset = reg->userspace_addr -
- (uintptr_t) qemu_get_ram_block_host_ptr(ram_addr);
+ (uintptr_t) qemu_get_ram_block_host_ptr(mr->ram_block);
assert(fd_num < VHOST_MEMORY_MAX_NREGIONS);
fds[fd_num++] = fd;
}
@@ -622,11 +623,13 @@ static bool vhost_user_can_merge(struct vhost_dev *dev,
mr = qemu_ram_addr_from_host((void *)(uintptr_t)start1, &ram_addr);
assert(mr);
- mfd = qemu_get_ram_fd(ram_addr);
+ assert(mr->ram_block);
+ mfd = mr->ram_block->fd;
mr = qemu_ram_addr_from_host((void *)(uintptr_t)start2, &ram_addr);
assert(mr);
- rfd = qemu_get_ram_fd(ram_addr);
+ assert(mr->ram_block);
+ rfd = mr->ram_block->fd;
return mfd == rfd;
}
diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index 5b6e1b8..9a01d4a 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -105,9 +105,7 @@ RAMBlock *qemu_ram_alloc_resizeable(ram_addr_t size, ram_addr_t max_size,
uint64_t length,
void *host),
MemoryRegion *mr, Error **errp);
-int qemu_get_ram_fd(ram_addr_t addr);
-void qemu_set_ram_fd(ram_addr_t addr, int fd);
-void *qemu_get_ram_block_host_ptr(ram_addr_t addr);
+void *qemu_get_ram_block_host_ptr(RAMBlock *ram_block);
void qemu_ram_free(RAMBlock *block);
int qemu_ram_resize(RAMBlock *block, ram_addr_t newsize, Error **errp);
diff --git a/memory.c b/memory.c
index 239e6da..9cff7e2 100644
--- a/memory.c
+++ b/memory.c
@@ -1641,7 +1641,7 @@ int memory_region_get_fd(MemoryRegion *mr)
assert(mr->ram_block);
- return qemu_get_ram_fd(memory_region_get_ram_addr(mr) & TARGET_PAGE_MASK);
+ return mr->ram_block->fd;
}
void *memory_region_get_ram_ptr(MemoryRegion *mr)
--
1.7.12.4
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [PATCH v3 3/3] memory: drop some wrappers that waste cpu cycle
2016-05-12 10:07 ` [Qemu-devel] [PATCH v3 3/3] memory: drop some wrappers that waste cpu cycle Gonglei
@ 2016-05-17 1:50 ` Fam Zheng
0 siblings, 0 replies; 5+ messages in thread
From: Fam Zheng @ 2016-05-17 1:50 UTC (permalink / raw)
To: Gonglei; +Cc: qemu-devel, pbonzini, peter.huangpeng
On Thu, 05/12 18:07, Gonglei wrote:
> For better performance, we can use RAMblock
> directly stored in memory_region at present.
>
> Signed-off-by: Gonglei <arei.gonglei@huawei.com>
> ---
> exec.c | 33 ++-------------------------------
> hw/misc/ivshmem.c | 8 +++++---
> hw/virtio/vhost-user.c | 13 ++++++++-----
> include/exec/ram_addr.h | 4 +---
> memory.c | 2 +-
> 5 files changed, 17 insertions(+), 43 deletions(-)
>
> diff --git a/exec.c b/exec.c
> index 117c9a8..f8de928 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -1812,38 +1812,9 @@ void qemu_ram_remap(ram_addr_t addr, ram_addr_t length)
> }
> #endif /* !_WIN32 */
>
> -int qemu_get_ram_fd(ram_addr_t addr)
> +void *qemu_get_ram_block_host_ptr(RAMBlock *ram_block)
> {
> - RAMBlock *block;
> - int fd;
> -
> - rcu_read_lock();
> - block = qemu_get_ram_block(addr);
> - fd = block->fd;
> - rcu_read_unlock();
> - return fd;
> -}
> -
> -void qemu_set_ram_fd(ram_addr_t addr, int fd)
> -{
> - RAMBlock *block;
> -
> - rcu_read_lock();
> - block = qemu_get_ram_block(addr);
> - block->fd = fd;
> - rcu_read_unlock();
> -}
> -
> -void *qemu_get_ram_block_host_ptr(ram_addr_t addr)
> -{
> - RAMBlock *block;
> - void *ptr;
> -
> - rcu_read_lock();
> - block = qemu_get_ram_block(addr);
> - ptr = ramblock_ptr(block, 0);
> - rcu_read_unlock();
> - return ptr;
> + return ramblock_ptr(ram_block, 0);
> }
>
> /* Return a host pointer to ram allocated with qemu_ram_alloc.
> diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
> index e40f23b..1e930fa 100644
> --- a/hw/misc/ivshmem.c
> +++ b/hw/misc/ivshmem.c
> @@ -533,7 +533,9 @@ static void process_msg_shmem(IVShmemState *s, int fd, Error **errp)
> }
> memory_region_init_ram_ptr(&s->server_bar2, OBJECT(s),
> "ivshmem.bar2", size, ptr);
> - qemu_set_ram_fd(memory_region_get_ram_addr(&s->server_bar2), fd);
> + assert(s->server_bar2.ram_block);
> + s->server_bar2.ram_block->fd = fd;
> +
> s->ivshmem_bar2 = &s->server_bar2;
> }
>
> @@ -939,8 +941,8 @@ static void ivshmem_exit(PCIDevice *dev)
> error_report("Failed to munmap shared memory %s",
> strerror(errno));
> }
> -
> - fd = qemu_get_ram_fd(memory_region_get_ram_addr(s->ivshmem_bar2));
Maybe this is okay but personally I think it is cleaner to add a
qemu_{set,get}_ramblock_fd pair.
Fam
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2016-05-17 1:50 UTC | newest]
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2016-05-12 10:07 [Qemu-devel] [PATCH v3 0/3] memory: some little optimizations Gonglei
2016-05-12 10:07 ` [Qemu-devel] [PATCH v3 1/3] memory: drop find_ram_block() Gonglei
2016-05-12 10:07 ` [Qemu-devel] [PATCH v3 2/3] exec: adjust rcu_read_lock requirement Gonglei
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