forked from luck/tmp_suning_uos_patched
be2c6b1990
o Jeff Moyer was doing some testing on a RAM backed disk and blkiocg_lookup_group() showed up high overhead after memcpy(). Similarly somebody else reported that blkiocg_lookup_group() is eating 6% extra cpu. Though looking at the code I can't think why the overhead of this function is so high. One thing is that it is called with very high frequency (once for every IO). o For lot of folks blkio controller will be compiled in but they might not have actually created cgroups. Hence optimize the case of root cgroup where we can avoid calling blkiocg_lookup_group() if IO is happening in root group (common case). Reported-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com> |
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| .. | ||
| blk-cgroup.c | ||
| blk-cgroup.h | ||
| blk-core.c | ||
| blk-exec.c | ||
| blk-flush.c | ||
| blk-integrity.c | ||
| blk-ioc.c | ||
| blk-iopoll.c | ||
| blk-lib.c | ||
| blk-map.c | ||
| blk-merge.c | ||
| blk-settings.c | ||
| blk-softirq.c | ||
| blk-sysfs.c | ||
| blk-tag.c | ||
| blk-throttle.c | ||
| blk-timeout.c | ||
| blk.h | ||
| bsg.c | ||
| cfq-iosched.c | ||
| cfq.h | ||
| compat_ioctl.c | ||
| deadline-iosched.c | ||
| elevator.c | ||
| genhd.c | ||
| ioctl.c | ||
| Kconfig | ||
| Kconfig.iosched | ||
| Makefile | ||
| noop-iosched.c | ||
| scsi_ioctl.c | ||