hollalinux
/
linux-sg2042
mirror of https://github.com/sophgo/linux-riscv.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

percpu-rwsem: use synchronize_sched_expedited 

Use synchronize_sched_expedited() instead of synchronize_sched()
to improve mount speed.

This patch improves mount time from 0.500s to 0.013s for Jeff's
test-case.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reported-and-tested-by: Jeff Chua <jeff.chua.linux@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Mikulas Patocka 2012-11-27 22:59:52 -05:00 committed by Linus Torvalds
parent e23739b4ad
commit 4b05a1c74d
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
include/linux/percpu-rwsem.h
View File

@ -13,7 +13,7 @@ struct percpu_rw_semaphore {
}; };
#define light_mb() barrier() #define light_mb() barrier()
#define heavy_mb() synchronize_sched() #define heavy_mb() synchronize_sched_expedited()
static inline void percpu_down_read(struct percpu_rw_semaphore *p) static inline void percpu_down_read(struct percpu_rw_semaphore *p)
{ {
@ -51,7 +51,7 @@ static inline void percpu_down_write(struct percpu_rw_semaphore *p)
{ {
mutex_lock(&p->mtx); mutex_lock(&p->mtx);
p->locked = true; p->locked = true;
synchronize_sched(); /* make sure that all readers exit the rcu_read_lock_sched region */ synchronize_sched_expedited(); /* make sure that all readers exit the rcu_read_lock_sched region */
while (__percpu_count(p->counters)) while (__percpu_count(p->counters))
msleep(1); msleep(1);
heavy_mb(); /* C, between read of p->counter and write to data, paired with B */ heavy_mb(); /* C, between read of p->counter and write to data, paired with B */