From: martin.petersen@oracle.com (Martin K. Petersen)
Subject: [PATCH V4 0/3] scsi: core: avoid big pre-allocation for sg list
Date: Mon, 13 May 2019 22:06:13 -0400 [thread overview]
Message-ID: <yq1a7fpg57u.fsf@oracle.com> (raw)
In-Reply-To: <20190428073932.9898-1-ming.lei@redhat.com> (Ming Lei's message of "Sun, 28 Apr 2019 15:39:29 +0800")
Ming,
> Since supporting to blk-mq, big pre-allocation for sg list is
> introduced, this way is very unfriendly wrt. memory consumption.
Applied to 5.3/scsi-queue with some clarifications to the commit
descriptions.
I am not entirely sold on 1 for the inline protection SGL size. NVMe
over PCIe is pretty constrained thanks to the metadata pointer whereas
SCSI DIX uses a real SGL for the PI. Consequently, straddling a page is
not that uncommon for large, sequential I/Os.
But let's try it out. If performance suffers substantially, we may want
to bump it to 2.
--
Martin K. Petersen Oracle Linux Engineering
prev parent reply other threads:[~2019-05-14 2:06 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-28 7:39 [PATCH V4 0/3] scsi: core: avoid big pre-allocation for sg list Ming Lei
2019-04-28 7:39 ` [PATCH V4 1/3] lib/sg_pool.c: improve APIs for allocating sg pool Ming Lei
2019-04-28 12:04 ` Christoph Hellwig
2019-05-05 1:10 ` [PATCH V4 0/3] scsi: core: avoid big pre-allocation for sg list Ming Lei
2019-05-14 2:06 ` Martin K. Petersen [this message]
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