Date: Fri, 15 Sep 2017 20:16:06 +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: r323625 - head/sys/cam/nvme Message-ID: <201709152016.v8FKG675050922@repo.freebsd.org>
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Author: imp Date: Fri Sep 15 20:16:06 2017 New Revision: 323625 URL: https://svnweb.freebsd.org/changeset/base/323625 Log: Allow multiple TRIMs to be done for nda Don't call cam_iosched_trim_done or cam_iosched_submit_trim for nda since its hardware can handle almost an arbitrary number of TRIMs and we don't have to be careful to only ever do one. Sponsored by: Netflix Modified: head/sys/cam/nvme/nvme_da.c Modified: head/sys/cam/nvme/nvme_da.c ============================================================================== --- head/sys/cam/nvme/nvme_da.c Fri Sep 15 20:15:55 2017 (r323624) +++ head/sys/cam/nvme/nvme_da.c Fri Sep 15 20:16:06 2017 (r323625) @@ -920,7 +920,12 @@ ndastart(struct cam_periph *periph, union ccb *start_c nda_nvme_trim(softc, &start_ccb->nvmeio, dsm_range, 1); start_ccb->ccb_h.ccb_state = NDA_CCB_TRIM; start_ccb->ccb_h.flags |= CAM_UNLOCKED; - cam_iosched_submit_trim(softc->cam_iosched); /* XXX */ + /* + * Note: We can have multiple TRIMs in flight, so we don't call + * cam_iosched_submit_trim(softc->cam_iosched); + * since that forces the I/O scheduler to only schedule one at a time. + * On NVMe drives, this is a performance disaster. + */ goto out; } case BIO_FLUSH: @@ -1013,7 +1018,11 @@ ndadone(struct cam_periph *periph, union ccb *done_ccb TAILQ_INIT(&queue); TAILQ_CONCAT(&queue, &softc->trim_req.bps, bio_queue); #endif - cam_iosched_trim_done(softc->cam_iosched); + /* + * Since we can have multiple trims in flight, we don't + * need to call this here. + * cam_iosched_trim_done(softc->cam_iosched); + */ ndaschedule(periph); cam_periph_unlock(periph); #ifdef notyet
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