Messages in this thread |  | | Date | Sat, 21 Mar 2009 03:03:09 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH] block: forbid to re-enable I/O stat accounting |
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Please fix your email headers - what I received was
From: Jerome Marchand <jmarchan@redhat.com> To: unlisted-recipients:;;@imap1.linux-foundation.org (no To-header on input) Cc: Jens Axboe <axboe@kernel.dk>
On Thu, 19 Mar 2009 11:36:50 +0100 Jerome Marchand <jmarchan@redhat.com> wrote:
> When we stop I/O stat accounting we stop to update the in-flight > requests counter and we need this counter to be reliable for > accounting I/O stats. Unfortunately updating in_flight field may > affect performance. So, until we have a better solution, just forbid > to re-enable I/O stat accounting after it has been disabled.
hm. Is it really so hard to just quiesce the device until all in-flight requests have drained? freeze_bdev() might be a suitable starting point?
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