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| author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2009-07-21 20:25:05 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-08-04 20:28:25 +0200 |
| commit | 97fd9ed48ce2b807edc363bef3e817aeeb5cd5e6 (patch) | |
| tree | ffb221aba4444bd3a1f84affd2aba7aa0784484e /drivers/usb/gadget/rndis.c | |
| parent | fbd90375d7531927d312766b548376d909811b4d (diff) | |
| download | lwn-97fd9ed48ce2b807edc363bef3e817aeeb5cd5e6.tar.gz lwn-97fd9ed48ce2b807edc363bef3e817aeeb5cd5e6.zip | |
timers: Cache __next_timer_interrupt result
Each time a cpu goes to sleep on a NOHZ=y system the timer
wheel is searched for the next timer interrupt. It can take
quite a few cycles to find the next pending timer.
This patch adds a field to tvec_base that caches the result of
__next_timer_interrupt.
The hit ratio is around 80% on my thinkpad under normal use, on
a server I've seen hit ratios from 5% to 95% dependent on the
workload.
-v2: jiffies wrap fixes
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Venki Pallipadi <venkatesh.pallipadi@intel.com>
LKML-Reference: <20090721202505.7d56a079@skybase>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'drivers/usb/gadget/rndis.c')
0 files changed, 0 insertions, 0 deletions