From: Christoph Hellwig <hch@lst.de>
To: tj@kernel.org, martin.petersen@oracle.com, axboe@kernel.dk
Cc: linux-ide@vger.kernel.org, linux-scsi@vger.kernel.org,
linux-block@vger.kernel.org
Subject: [PATCH 7/7] sd: use ZERO_PAGE for WRITE_SAME payloads
Date: Mon, 20 Mar 2017 16:43:19 -0400 [thread overview]
Message-ID: <20170320204319.12628-8-hch@lst.de> (raw)
In-Reply-To: <20170320204319.12628-1-hch@lst.de>
We're never touching the contents of the page, so save a memory
allocation for these cases.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/scsi/sd.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index c18fe9ff1f8f..af632e350ab4 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -756,7 +756,7 @@ static int sd_setup_write_same16_cmnd(struct scsi_cmnd *cmd)
u32 nr_sectors = blk_rq_sectors(rq) >> (ilog2(sdp->sector_size) - 9);
u32 data_len = sdp->sector_size;
- rq->special_vec.bv_page = alloc_page(GFP_ATOMIC | __GFP_ZERO);
+ rq->special_vec.bv_page = ZERO_PAGE(0);
if (!rq->special_vec.bv_page)
return BLKPREP_DEFER;
rq->special_vec.bv_offset = 0;
@@ -785,7 +785,7 @@ static int sd_setup_write_same10_cmnd(struct scsi_cmnd *cmd, bool unmap)
u32 nr_sectors = blk_rq_sectors(rq) >> (ilog2(sdp->sector_size) - 9);
u32 data_len = sdp->sector_size;
- rq->special_vec.bv_page = alloc_page(GFP_ATOMIC | __GFP_ZERO);
+ rq->special_vec.bv_page = ZERO_PAGE(0);
if (!rq->special_vec.bv_page)
return BLKPREP_DEFER;
rq->special_vec.bv_offset = 0;
@@ -1256,7 +1256,8 @@ static void sd_uninit_command(struct scsi_cmnd *SCpnt)
{
struct request *rq = SCpnt->request;
- if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
+ if ((rq->rq_flags & RQF_SPECIAL_PAYLOAD) &&
+ rq->special_vec.bv_page != ZERO_PAGE(0))
__free_page(rq->special_vec.bv_page);
if (SCpnt->cmnd != scsi_req(rq)->cmd) {
--
2.11.0
next prev parent reply other threads:[~2017-03-20 20:43 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-20 20:43 support ranges TRIM for libata Christoph Hellwig
2017-03-20 20:43 ` [PATCH 1/7] ѕd: split sd_setup_discard_cmnd Christoph Hellwig
2017-03-27 22:24 ` Bart Van Assche
2017-03-28 14:05 ` axboe
2017-03-30 8:49 ` hch
2017-03-20 20:43 ` [PATCH 2/7] sd: provide a new ata trim provisioning mode Christoph Hellwig
2017-03-27 22:40 ` Bart Van Assche
2017-03-20 20:43 ` [PATCH 3/7] libata: remove SCT WRITE SAME support Christoph Hellwig
2017-03-20 20:43 ` [PATCH 4/7] libata: simplify the trim implementation Christoph Hellwig
2017-03-20 20:43 ` [PATCH 5/7] block: add a max_discard_segment_size queue limit Christoph Hellwig
2017-03-27 23:09 ` Bart Van Assche
2017-03-20 20:43 ` [PATCH 6/7] sd: support multi-range TRIM for ATA disks Christoph Hellwig
2017-03-27 23:38 ` Bart Van Assche
2017-03-20 20:43 ` Christoph Hellwig [this message]
2017-03-27 23:40 ` [PATCH 7/7] sd: use ZERO_PAGE for WRITE_SAME payloads Bart Van Assche
2017-03-21 18:59 ` support ranges TRIM for libata Tejun Heo
2017-03-22 18:19 ` Christoph Hellwig
2017-03-23 13:47 ` James Bottomley
2017-03-23 13:55 ` Christoph Hellwig
2017-03-23 14:35 ` James Bottomley
2017-03-23 14:43 ` Christoph Hellwig
2017-03-23 15:04 ` Tejun Heo
2017-03-23 15:27 ` Christoph Hellwig
2017-03-23 15:30 ` Christoph Hellwig
2017-03-23 15:39 ` Martin K. Petersen
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