From: Zach Brown <zab-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
To: Kent Overstreet <koverstreet-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
Cc: linux-bcache-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
dm-devel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org,
tytso-3s7WtUTddSA@public.gmane.org
Subject: Re: [PATCH 4/5] aio: vmap ringbuffer
Date: Tue, 9 Oct 2012 15:58:36 -0700 [thread overview]
Message-ID: <20121009225836.GU26187@lenny.home.zabbo.net> (raw)
In-Reply-To: <20121009224428.GH29494-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
> Not if we decouple the ringbuffer size from max_requests.
Hmm, interesting.
> This would be useful to do anyways because right now, allocating a kiocb
> has to take a global refcount and check head and tail in the ringbuffer
> just so it can avoid overflowing the ringbuffer.
I'm not sure what you mean by a 'global refcount'.. do you mean the
per-mm ctx_lock?
> If we change aio_complete() so that if the ringbuffer is full then the
> kiocb just goes on a linked list - we can size the ringbuffer so this
> doesn't happen normally and avoid the global synchronization in the fast
> path.
How would completion events make their way from the list to the ring if
an app is only checking the ring for completions from userspace?
- z
next prev parent reply other threads:[~2012-10-09 22:58 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-09 6:39 [PATCH 1/5] aio: Kill return value of aio_complete() Kent Overstreet
[not found] ` <1349764760-21093-1-git-send-email-koverstreet-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-10-09 6:39 ` [PATCH 2/5] aio: kiocb_cancel() Kent Overstreet
[not found] ` <1349764760-21093-2-git-send-email-koverstreet-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-10-09 18:26 ` Zach Brown
[not found] ` <20121009182625.GM26187-fypN+1c5dIyjpB87vu3CluTW4wlIGRCZ@public.gmane.org>
2012-10-09 21:37 ` Kent Overstreet
[not found] ` <20121009213700.GF29494-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-10-10 11:03 ` Theodore Ts'o
[not found] ` <20121010110356.GA11468-AKGzg7BKzIDYtjvyW6yDsg@public.gmane.org>
2012-10-10 21:20 ` Zach Brown
[not found] ` <20121010212051.GD6371-fypN+1c5dIyjpB87vu3CluTW4wlIGRCZ@public.gmane.org>
2012-10-10 23:21 ` Theodore Ts'o
2012-10-11 2:41 ` Kent Overstreet
2012-10-09 6:39 ` [PATCH 5/5] aio: Refactor aio_read_evt, use cmxchg(), fix bug Kent Overstreet
[not found] ` <1349764760-21093-5-git-send-email-koverstreet-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-10-09 18:37 ` Zach Brown
[not found] ` <20121009183753.GP26187-fypN+1c5dIyjpB87vu3CluTW4wlIGRCZ@public.gmane.org>
2012-10-09 21:27 ` Kent Overstreet
[not found] ` <20121009212724.GD29494-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-10-09 22:47 ` Zach Brown
[not found] ` <20121009224703.GT26187-fypN+1c5dIyjpB87vu3CluTW4wlIGRCZ@public.gmane.org>
2012-10-09 22:55 ` Kent Overstreet
[not found] ` <20121009225509.GA26835-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-10-09 23:10 ` Zach Brown
[not found] ` <20121009231059.GV26187-fypN+1c5dIyjpB87vu3CluTW4wlIGRCZ@public.gmane.org>
2012-10-10 0:06 ` Kent Overstreet
[not found] ` <20121010000600.GB26835-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-10-10 0:26 ` Zach Brown
[not found] ` <20121010002634.GX26187-fypN+1c5dIyjpB87vu3CluTW4wlIGRCZ@public.gmane.org>
2012-10-10 0:47 ` Kent Overstreet
[not found] ` <20121010004746.GF26835-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-10-10 21:43 ` Zach Brown
[not found] ` <20121010214315.GE6371-fypN+1c5dIyjpB87vu3CluTW4wlIGRCZ@public.gmane.org>
2012-10-11 2:51 ` Kent Overstreet
[not found] ` <20121011025102.GE24174-jC9Py7bek1znysI04z7BkA@public.gmane.org>
2012-10-11 16:43 ` Zach Brown
2012-10-09 18:25 ` [PATCH 1/5] aio: Kill return value of aio_complete() Zach Brown
2012-10-09 6:39 ` [PATCH 3/5] aio: Rewrite refcounting Kent Overstreet
[not found] ` <1349764760-21093-3-git-send-email-koverstreet-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-10-09 18:27 ` Zach Brown
[not found] ` <20121009182755.GN26187-fypN+1c5dIyjpB87vu3CluTW4wlIGRCZ@public.gmane.org>
2012-10-09 22:21 ` Kent Overstreet
[not found] ` <20121009222153.GG29494-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-10-09 22:35 ` Zach Brown
[not found] ` <20121009223504.GS26187-fypN+1c5dIyjpB87vu3CluTW4wlIGRCZ@public.gmane.org>
2012-10-10 0:17 ` Kent Overstreet
2012-10-09 6:39 ` [PATCH 4/5] aio: vmap ringbuffer Kent Overstreet
[not found] ` <1349764760-21093-4-git-send-email-koverstreet-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-10-09 18:29 ` Zach Brown
2012-10-09 21:31 ` Kent Overstreet
[not found] ` <20121009213111.GE29494-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-10-09 22:32 ` Zach Brown
2012-10-09 22:44 ` Kent Overstreet
[not found] ` <20121009224428.GH29494-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-10-09 22:58 ` Zach Brown [this message]
[not found] ` <20121009225836.GU26187-fypN+1c5dIyjpB87vu3CluTW4wlIGRCZ@public.gmane.org>
2012-10-10 0:16 ` Kent Overstreet
[not found] ` <20121010001630.GC26835-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-10-10 0:36 ` Zach Brown
[not found] ` <20121010003626.GY26187-fypN+1c5dIyjpB87vu3CluTW4wlIGRCZ@public.gmane.org>
2012-10-10 1:09 ` Kent Overstreet
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