From: Dmitry Bogdanov <d.bogdanov@yadro.com>
To: Martin Petersen <martin.petersen@oracle.com>,
<target-devel@vger.kernel.org>
Cc: <linux-scsi@vger.kernel.org>, <linux@yadro.com>,
James Smart <james.smart@broadcom.com>,
Dmitry Bogdanov <d.bogdanov@yadro.com>,
Roman Bolshakov <r.bolshakov@yadro.com>
Subject: [PATCH 3/3] scsi: efct: decrease area under spinlock
Date: Tue, 14 Sep 2021 13:55:39 +0300 [thread overview]
Message-ID: <20210914105539.6942-4-d.bogdanov@yadro.com> (raw)
In-Reply-To: <20210914105539.6942-1-d.bogdanov@yadro.com>
Under session level spinlock node->active_ios_lock in
efct_scsi_io_alloc() there is a getting other spinlock of port level.
That lead to competition between sessions and even between IOs in the
same session due too much instructions under spinlock.
This change reduces spinlock area just to active_ios list for which
active_ios_lock is intended.
Spinlock CPU usage is decreased from 18% down to 13% in efct driver.
IOPS are increased from 220 kIOPS upto 264 kIOPS for one lun on my setup.
Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Signed-off-by: Dmitry Bogdanov <d.bogdanov@yadro.com>
---
drivers/scsi/elx/efct/efct_scsi.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/scsi/elx/efct/efct_scsi.c b/drivers/scsi/elx/efct/efct_scsi.c
index 40fb3a724c76..8535bb7eabd8 100644
--- a/drivers/scsi/elx/efct/efct_scsi.c
+++ b/drivers/scsi/elx/efct/efct_scsi.c
@@ -38,8 +38,6 @@ efct_scsi_io_alloc(struct efct_node *node)
xport = efct->xport;
- spin_lock_irqsave(&node->active_ios_lock, flags);
-
io = efct_io_pool_io_alloc(efct->xport->io_pool);
if (!io) {
efc_log_err(efct, "IO alloc Failed\n");
@@ -66,6 +64,7 @@ efct_scsi_io_alloc(struct efct_node *node)
/* Add to node's active_ios list */
INIT_LIST_HEAD(&io->list_entry);
+ spin_lock_irqsave(&node->active_ios_lock, flags);
list_add(&io->list_entry, &node->active_ios);
spin_unlock_irqrestore(&node->active_ios_lock, flags);
--
2.25.1
next prev parent reply other threads:[~2021-09-14 10:55 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-14 10:55 [PATCH 0/3] efct fixes & improvements Dmitry Bogdanov
2021-09-14 10:55 ` [PATCH 1/3] scsi: efct: add state in nport sm trace printout Dmitry Bogdanov
2021-09-15 12:45 ` Ram Kishore Vegesna
2021-09-14 10:55 ` [PATCH 2/3] scsi: efct: fix nport free Dmitry Bogdanov
2021-09-15 12:51 ` Ram Kishore Vegesna
2021-09-14 10:55 ` Dmitry Bogdanov [this message]
2021-09-15 12:51 ` [PATCH 3/3] scsi: efct: decrease area under spinlock Ram Kishore Vegesna
2021-09-22 4:05 ` [PATCH 0/3] efct fixes & improvements Martin K. Petersen
2021-09-29 4:20 ` Martin K. Petersen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210914105539.6942-4-d.bogdanov@yadro.com \
--to=d.bogdanov@yadro.com \
--cc=james.smart@broadcom.com \
--cc=linux-scsi@vger.kernel.org \
--cc=linux@yadro.com \
--cc=martin.petersen@oracle.com \
--cc=r.bolshakov@yadro.com \
--cc=target-devel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).