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ANDROID: GKI: add percpu_rwsem vendor hooks

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When a writer has set sem->block and is waiting for active readers
to complete, we still allow some specific new readers to entry
the critical section, which can help prevent priority inversion
from impacting system responsiveness and performance.

Bug: 334851707

Change-Id: I9e2a7df1efb326763487423d64bcf74d8dec23f8
Signed-off-by: zhujingpeng <zhujingpeng@vivo.com>
(cherry picked from commit 458cdb59f7719f81504d392daa95a8c99c30c276)
This commit is contained in:
zhujingpeng
2024-04-15 21:22:50 +08:00
committed by Treehugger Robot
parent 713c541144
commit be7f2eb0e8
3 changed files with 24 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files
drivers/android/vendor_hooks.c
+3
View File
@@ -488,3 +488,6 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_lock_folio_drop_mmap_end);
EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_filemap_update_page);
EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_hibernated_do_mem_alloc);
EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_hibernate_save_cmp_len);
EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_percpu_rwsem_down_read);
EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_percpu_rwsem_up_write);
EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_percpu_rwsem_wait_complete);
include/trace/hooks/dtask.h
+9
View File
@@ -106,6 +106,15 @@ DECLARE_HOOK(android_vh_sched_show_task,
DECLARE_HOOK(android_vh_percpu_rwsem_wq_add,
TP_PROTO(struct percpu_rw_semaphore *sem, bool reader),
TP_ARGS(sem, reader));
DECLARE_HOOK(android_vh_percpu_rwsem_down_read,
TP_PROTO(struct percpu_rw_semaphore *sem, bool try, bool *ret),
TP_ARGS(sem, try, ret));
DECLARE_HOOK(android_vh_percpu_rwsem_up_write,
TP_PROTO(struct percpu_rw_semaphore *sem),
TP_ARGS(sem));
DECLARE_RESTRICTED_HOOK(android_rvh_percpu_rwsem_wait_complete,
TP_PROTO(struct percpu_rw_semaphore *sem, long state, bool *complete),
TP_ARGS(sem, state, complete), 1);
struct mutex_waiter;
DECLARE_HOOK(android_vh_alter_mutex_list_add,
kernel/locking/percpu-rwsem.c
+12 -1
View File
@@ -182,9 +182,15 @@ static void percpu_rwsem_wait(struct percpu_rw_semaphore *sem, bool reader)
bool __sched __percpu_down_read(struct percpu_rw_semaphore *sem, bool try)
{
bool ret = false;
if (__percpu_down_read_trylock(sem))
return true;
trace_android_vh_percpu_rwsem_down_read(sem, try, &ret);
if (ret)
return true;
if (try)
return false;
@@ -240,6 +246,7 @@ static bool readers_active_check(struct percpu_rw_semaphore *sem)
void __sched percpu_down_write(struct percpu_rw_semaphore *sem)
{
bool contended = false;
bool complete = false;
might_sleep();
rwsem_acquire(&sem->dep_map, 0, 0, _RET_IP_);
@@ -266,7 +273,9 @@ void __sched percpu_down_write(struct percpu_rw_semaphore *sem)
*/
/* Wait for all active readers to complete. */
rcuwait_wait_event(&sem->writer, readers_active_check(sem), TASK_UNINTERRUPTIBLE);
trace_android_rvh_percpu_rwsem_wait_complete(sem, TASK_UNINTERRUPTIBLE, &complete);
if (!complete)
rcuwait_wait_event(&sem->writer, readers_active_check(sem), TASK_UNINTERRUPTIBLE);
if (contended)
trace_contention_end(sem, 0);
trace_android_vh_record_pcpu_rwsem_starttime(sem, jiffies);
@@ -277,6 +286,8 @@ void percpu_up_write(struct percpu_rw_semaphore *sem)
{
rwsem_release(&sem->dep_map, _RET_IP_);
trace_android_vh_percpu_rwsem_up_write(sem);
/*
* Signal the writer is done, no fast path yet.
*