Date: Thu, 22 Feb 2018 05:43:50 +0000 (UTC) From: Warner Losh <imp@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r329814 - head/sys/cam Message-ID: <201802220543.w1M5hobv068907@repo.freebsd.org>
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Author: imp Date: Thu Feb 22 05:43:50 2018 New Revision: 329814 URL: https://svnweb.freebsd.org/changeset/base/329814 Log: Note when we tick. To help implement a policy of 'queue all trims until next I/O sched tick' policy to help coalesce them, note when we tick so we can do something special on the first call after the tick to get more work. Sponsored by: Netflix Modified: head/sys/cam/cam_iosched.c Modified: head/sys/cam/cam_iosched.c ============================================================================== --- head/sys/cam/cam_iosched.c Thu Feb 22 05:43:45 2018 (r329813) +++ head/sys/cam/cam_iosched.c Thu Feb 22 05:43:50 2018 (r329814) @@ -60,6 +60,19 @@ static MALLOC_DEFINE(M_CAMSCHED, "CAM I/O Scheduler", "CAM I/O Scheduler buffers"); /* + * Trim or similar currently pending completion. Should only be set for + * those drivers wishing only one Trim active at a time. + */ +#define CAM_IOSCHED_FLAG_TRIM_ACTIVE (1ul << 0) + /* Callout active, and needs to be torn down */ +#define CAM_IOSCHED_FLAG_CALLOUT_ACTIVE (1ul << 1) + /* Timer has just ticked */ +#define CAM_IOSCHED_FLAG_TICK (1ul << 2) + + /* Periph drivers set these flags to indicate work */ +#define CAM_IOSCHED_FLAG_WORK_FLAGS ((0xffffu) << 16) + +/* * Default I/O scheduler for FreeBSD. This implementation is just a thin-vineer * over the bioq_* interface, with notions of separate calls for normal I/O and * for trims. @@ -574,6 +587,7 @@ cam_iosched_ticker(void *arg) cam_iosched_limiter_tick(&isc->write_stats); cam_iosched_limiter_tick(&isc->trim_stats); + isc->flags |= CAM_IOSCHED_FLAGS_TICK; cam_iosched_schedule(isc, isc->periph); /* @@ -701,17 +715,6 @@ cam_iosched_cl_maybe_steer(struct control_loop *clp) } #endif -/* - * Trim or similar currently pending completion. Should only be set for - * those drivers wishing only one Trim active at a time. - */ -#define CAM_IOSCHED_FLAG_TRIM_ACTIVE (1ul << 0) - /* Callout active, and needs to be torn down */ -#define CAM_IOSCHED_FLAG_CALLOUT_ACTIVE (1ul << 1) - - /* Periph drivers set these flags to indicate work */ -#define CAM_IOSCHED_FLAG_WORK_FLAGS ((0xffffu) << 16) - #ifdef CAM_IOSCHED_DYNAMIC static void cam_iosched_io_metric_update(struct cam_iosched_softc *isc, @@ -1322,6 +1325,10 @@ struct bio * cam_iosched_next_bio(struct cam_iosched_softc *isc) { struct bio *bp; + bool wastick; + + wastick = !!(isc->flags & CAM_IOSCHED_FLAGS_TICK); + isc->flags &= ~CAM_IOSCHED_FLAGS_TICK; /* * See if we have a trim that can be scheduled. We can only send one
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