linux-hyperv.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Dexuan Cui <decui@microsoft.com>
To: Ming Lei <ming.lei@redhat.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>,
	Josh Triplett <josh@joshtriplett.org>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	"jejb@linux.ibm.com" <jejb@linux.ibm.com>,
	"martin.petersen@oracle.com" <martin.petersen@oracle.com>,
	"linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"hch@lst.de" <hch@lst.de>,
	"bvanassche@acm.org" <bvanassche@acm.org>,
	"hare@suse.de" <hare@suse.de>,
	Michael Kelley <mikelley@microsoft.com>,
	Long Li <longli@microsoft.com>,
	"linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>,
	"wei.liu@kernel.org" <wei.liu@kernel.org>,
	Stephen Hemminger <sthemmin@microsoft.com>,
	Haiyang Zhang <haiyangz@microsoft.com>,
	KY Srinivasan <kys@microsoft.com>,
	"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>
Subject: RE: [PATCH] scsi: storvsc: Fix a panic in the hibernation procedure
Date: Wed, 22 Apr 2020 18:01:36 +0000	[thread overview]
Message-ID: <HK0P153MB027315BB6DD813888E073664BFD20@HK0P153MB0273.APCP153.PROD.OUTLOOK.COM> (raw)
In-Reply-To: <20200422092351.GF299948@T590>

> From: Ming Lei <ming.lei@redhat.com>
> Sent: Wednesday, April 22, 2020 2:24 AM
> > ...
> > storvsc_suspend() -> scsi_host_block() is only called in the hibernation
> > path, which is not a hot path at all, so IMHO we don't really care if it
> > takes 10ms or 100ms or even 1s. :-)  BTW, in my test, typically the
> 
> Are you sure the 'we' can cover all users?

I actully only meant I don't have any performance concern in this path
storvsc_suspend() -> scsi_host_block()  :-)

Thanks for your effort to improve the scsi_host_block() API in the patch
[PATCH] scsi: avoid to run synchronize_rcu for each device in scsi_host_block.
 
> > scsi_host_block() here takes about 3ms in my 40-vCPU VM.
> 
> If more LUNs are added, the time should be increased proportionallly,
> that is why I think scsi_host_block() is bad.
> 
> Thanks,
> Ming

FWIW, if the time increases linearly against the number of the LUNs, it
looks typically it's still fast enough for storvsc_suspend().

Thanks,
-- Dexuan

  parent reply	other threads:[~2020-04-22 18:01 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-22  0:17 [PATCH] scsi: storvsc: Fix a panic in the hibernation procedure Dexuan Cui
2020-04-22  1:28 ` Ming Lei
2020-04-22  1:48   ` Dexuan Cui
2020-04-22  2:01     ` Ming Lei
2020-04-22  3:08       ` Paul E. McKenney
2020-04-22  4:16         ` Ming Lei
2020-04-22  4:58           ` Dexuan Cui
2020-04-22  9:23             ` Ming Lei
2020-04-22 16:19               ` Paul E. McKenney
2020-04-22 18:01               ` Dexuan Cui [this message]
2020-04-22  2:06     ` Ming Lei
2020-04-22  5:02 ` Bart Van Assche
2020-04-22  6:24   ` Dexuan Cui
2020-04-22 19:56     ` Bart Van Assche
2020-04-23  7:04       ` Dexuan Cui
2020-04-23 16:37         ` Bart Van Assche
2020-04-23 18:29           ` Dexuan Cui
2020-04-23 23:25             ` Bart Van Assche
2020-04-24  2:40               ` Dexuan Cui
2020-04-24  3:45               ` Dexuan Cui

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=HK0P153MB027315BB6DD813888E073664BFD20@HK0P153MB0273.APCP153.PROD.OUTLOOK.COM \
    --to=decui@microsoft.com \
    --cc=bvanassche@acm.org \
    --cc=haiyangz@microsoft.com \
    --cc=hare@suse.de \
    --cc=hch@lst.de \
    --cc=jejb@linux.ibm.com \
    --cc=josh@joshtriplett.org \
    --cc=kys@microsoft.com \
    --cc=linux-hyperv@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pm@vger.kernel.org \
    --cc=linux-scsi@vger.kernel.org \
    --cc=longli@microsoft.com \
    --cc=martin.petersen@oracle.com \
    --cc=mikelley@microsoft.com \
    --cc=ming.lei@redhat.com \
    --cc=paulmck@kernel.org \
    --cc=rjw@rjwysocki.net \
    --cc=sthemmin@microsoft.com \
    --cc=wei.liu@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).