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authorMing Lei <ming.lei@redhat.com>2019-06-18 03:37:55 +0200
committerMartin K. Petersen <martin.petersen@oracle.com>2019-06-20 21:21:33 +0200
commit57ef4e510939e305ad905cc54b8031401ff5450e (patch)
tree3238204aac5cace7ffda1f7eb2d1b4dce8b49152 /drivers/scsi/ppa.c
parentscsi: pcmcia: nsp_cs: use sg helper to iterate over scatterlist (diff)
downloadlinux-57ef4e510939e305ad905cc54b8031401ff5450e.tar.xz
linux-57ef4e510939e305ad905cc54b8031401ff5450e.zip
scsi: ppa: use sg helper to iterate over scatterlist
Unlike the legacy I/O path, scsi-mq preallocates a large array to hold the scatterlist for each request. This static allocation can consume substantial amounts of memory on modern controllers which support a large number of concurrently outstanding requests. To facilitate a switch to a smaller static allocation combined with a dynamic allocation for requests that need it, we need to make sure all SCSI drivers handle chained scatterlists correctly. Convert remaining drivers that directly dereference the scatterlist array to using the iterator functions. [mkp: clarified commit message] Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi/ppa.c')
-rw-r--r--drivers/scsi/ppa.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/scsi/ppa.c b/drivers/scsi/ppa.c
index 35213082e933..a406cc825426 100644
--- a/drivers/scsi/ppa.c
+++ b/drivers/scsi/ppa.c
@@ -590,7 +590,7 @@ static int ppa_completion(struct scsi_cmnd *cmd)
if (cmd->SCp.buffer && !cmd->SCp.this_residual) {
/* if scatter/gather, advance to the next segment */
if (cmd->SCp.buffers_residual--) {
- cmd->SCp.buffer++;
+ cmd->SCp.buffer = sg_next(cmd->SCp.buffer);
cmd->SCp.this_residual =
cmd->SCp.buffer->length;
cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);