From bde8b6e3ee817b9a3e6893056750fb04480cf86c Mon Sep 17 00:00:00 2001 From: mav Date: Thu, 19 Feb 2015 13:06:38 +0000 Subject: [PATCH] MFC r278619: Make WRITE SAME commands respect physical block size. This change by 2-3 times improves performance of misaligned WRITE SAME commands by avoiding unneeded read-modify-write cycles inside ZFS. git-svn-id: svn://svn.freebsd.org/base/stable/10@278999 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f --- sys/cam/ctl/ctl_backend_block.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/sys/cam/ctl/ctl_backend_block.c b/sys/cam/ctl/ctl_backend_block.c index 3f344bd71..1c126e863 100644 --- a/sys/cam/ctl/ctl_backend_block.c +++ b/sys/cam/ctl/ctl_backend_block.c @@ -1190,7 +1190,7 @@ ctl_be_block_cw_dispatch_ws(struct ctl_be_block_lun *be_lun, struct ctl_be_block_io *beio; struct ctl_be_block_softc *softc; struct ctl_lba_len_flags *lbalen; - uint64_t len_left, lba; + uint64_t len_left, lba, pb, pbo, adj; int i, seglen; uint8_t *buf, *end; @@ -1244,6 +1244,8 @@ ctl_be_block_cw_dispatch_ws(struct ctl_be_block_lun *be_lun, DPRINTF("WRITE SAME at LBA %jx len %u\n", (uintmax_t)lbalen->lba, lbalen->len); + pb = (uint64_t)be_lun->blocksize << be_lun->pblockexp; + pbo = pb - (uint64_t)be_lun->blocksize * be_lun->pblockoff; len_left = (uint64_t)lbalen->len * be_lun->blocksize; for (i = 0, lba = 0; i < CTLBLK_MAX_SEGS && len_left > 0; i++) { @@ -1251,7 +1253,15 @@ ctl_be_block_cw_dispatch_ws(struct ctl_be_block_lun *be_lun, * Setup the S/G entry for this chunk. */ seglen = MIN(CTLBLK_MAX_SEG, len_left); - seglen -= seglen % be_lun->blocksize; + if (pb > be_lun->blocksize) { + adj = ((lbalen->lba + lba) * be_lun->blocksize + + seglen - pbo) % pb; + if (seglen > adj) + seglen -= adj; + else + seglen -= seglen % be_lun->blocksize; + } else + seglen -= seglen % be_lun->blocksize; beio->sg_segs[i].len = seglen; beio->sg_segs[i].addr = uma_zalloc(be_lun->lun_zone, M_WAITOK); -- 2.45.0