From: Josef Bacik <josef@toxicpanda.com>
To: Liu Bo <bo.li.liu@oracle.com>
Cc: linux-btrfs@vger.kernel.org
Subject: Re: [PATCH] Btrfs: make plug in writing meta blocks really work
Date: Mon, 21 Aug 2017 13:48:01 -0400 [thread overview]
Message-ID: <20170821174800.GF23807@destiny> (raw)
In-Reply-To: <20170818174207.21613-1-bo.li.liu@oracle.com>
On Fri, Aug 18, 2017 at 11:42:07AM -0600, Liu Bo wrote:
> We have started plug in btrfs_write_and_wait_marked_extents() but the
> generated IOs actually go to device's schedule IO list where the work
> is doing in another task, thus the started plug doesn't make any
> sense.
>
> And since we wait for IOs immediately after writing meta blocks, it's
> the same case as writing log tree, doing sync submit can merge more
> IOs.
>
We're plugging when we do the per-device scheduled IO right? So we aren't
really gaining anything by it being async. Also we do a lot of work between the
time that we start writing the marked extents for the tree-log and when we
actually wait for them, so we really don't want to do a synchronous write out in
that case. Instead move the sync_writers into write_and_wait_marked_extents.
Thanks,
Josef
next prev parent reply other threads:[~2017-08-21 17:48 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-18 17:42 [PATCH] Btrfs: make plug in writing meta blocks really work Liu Bo
2017-08-21 17:48 ` Josef Bacik [this message]
2017-08-21 19:14 ` Liu Bo
2017-08-21 19:23 ` Josef Bacik
2017-08-21 19:54 ` Liu Bo
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