android_kernel_xiaomi_sm8350/arch/s390/lib
Martin Schwidefsky 951f22d5b1 [PATCH] s390: spin lock retry
Split spin lock and r/w lock implementation into a single try which is done
inline and an out of line function that repeatedly tries to get the lock
before doing the cpu_relax().  Add a system control to set the number of
retries before a cpu is yielded.

The reason for the spin lock retry is that the diagnose 0x44 that is used to
give up the virtual cpu is quite expensive.  For spin locks that are held only
for a short period of time the costs of the diagnoses outweights the savings
for spin locks that are held for a longer timer.  The default retry count is
1000.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-27 16:26:04 -07:00
..
delay.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
Makefile [PATCH] s390: spin lock retry 2005-07-27 16:26:04 -07:00
spinlock.c [PATCH] s390: spin lock retry 2005-07-27 16:26:04 -07:00
string.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
uaccess64.S Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
uaccess.S Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00