From: Mike Snitzer <snitzer@redhat.com>
To: Frank Mayhar <fmayhar@google.com>
Cc: device-mapper development <dm-devel@redhat.com>,
linux-kernel@vger.kernel.org
Subject: Re: dm: Make MIN_IOS, et al, tunable via sysctl.
Date: Mon, 19 Aug 2013 14:15:25 -0400 [thread overview]
Message-ID: <20130819181524.GA28765@redhat.com> (raw)
In-Reply-To: <1376934845.24869.43.camel@bobble.lax.corp.google.com>
On Mon, Aug 19 2013 at 1:54pm -0400,
Frank Mayhar <fmayhar@google.com> wrote:
> On Mon, 2013-08-19 at 10:00 -0400, Mike Snitzer wrote:
> > Performance isn't the concern. The concern is: does DM allow for
> > forward progress if the system's memory is completely exhausted?
> >
> > This is why request-based has such an extensive reserve, because it
> > needs to account for cloning the largest possible request that comes in
> > (with multiple bios).
>
> Thanks for the response. In our particular case, I/O will be file
> system based and over a network, which makes it pretty easy for us to be
> sure that large I/Os never happen. That notwithstanding, however, as
> you said it just seems reasonable to make these values configurable.
>
> I'm also looking at making some similar constants in dm-verity and
> dm-bufio configurable in the same way and for similar reasons.
OK, would be helpful if you were to split each patch out, e.g. separate
patches for DM core, verity, bufio, etc. Reserve the background context
to the 0th patch header (or DM core patch). With more precise patch
headers that document the new tunable that is exposed by each patch.
It would also be nice to see these tunables get documented in the
appropriate Documentation/device-mapper/ file too.
Thanks for working on this. I'll have time to review/assist these
changes in the near term.
next prev parent reply other threads:[~2013-08-19 18:15 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-09 17:48 [PATCH] dm: Make MIN_IOS, et al, tunable via sysctl Frank Mayhar
2013-08-13 16:41 ` Frank Mayhar
2013-08-16 22:58 ` Frank Mayhar
2013-08-17 12:30 ` [dm-devel] " Alasdair G Kergon
2013-08-19 13:40 ` Mike Snitzer
2013-08-19 15:04 ` Frank Mayhar
2013-08-19 14:00 ` Mike Snitzer
2013-08-19 14:00 ` Mike Snitzer
2013-08-19 17:54 ` [dm-devel] " Frank Mayhar
2013-08-19 18:15 ` Mike Snitzer [this message]
2013-08-20 21:44 ` Mikulas Patocka
2013-08-20 21:52 ` Frank Mayhar
2013-08-20 21:41 ` Mikulas Patocka
2013-08-20 21:22 ` [dm-devel] [PATCH] " Mikulas Patocka
2013-08-20 21:28 ` Frank Mayhar
2013-08-20 21:47 ` Mikulas Patocka
2013-08-20 21:57 ` Frank Mayhar
2013-08-20 22:24 ` Mike Snitzer
2013-08-20 22:52 ` Mikulas Patocka
2013-08-20 23:14 ` Frank Mayhar
2013-08-22 17:26 ` Frank Mayhar
2013-08-26 14:28 ` Mikulas Patocka
2013-09-12 22:24 ` [PATCH 0/7] dm: allow mempool and bioset reserves to be tuned Mike Snitzer
2013-09-12 22:24 ` [PATCH 1/7] dm: lower bio-based mempool reservation Mike Snitzer
2013-09-12 22:40 ` Mikulas Patocka
2013-09-12 22:24 ` [PATCH 2/7] dm: add reserved_rq_based_ios module parameter Mike Snitzer
2013-09-12 22:45 ` Mikulas Patocka
2013-09-12 23:15 ` Mike Snitzer
2013-09-12 23:27 ` Mikulas Patocka
2013-09-12 23:32 ` Mike Snitzer
2013-09-12 22:24 ` [PATCH 3/7] dm: add reserved_bio_based_ios " Mike Snitzer
2013-09-12 22:47 ` Mikulas Patocka
2013-09-12 23:11 ` Mike Snitzer
2013-09-12 23:17 ` Mikulas Patocka
2013-09-18 15:17 ` Frank Mayhar
2013-09-12 22:24 ` [PATCH 4/7] dm io: use dm_get_reserved_bio_based_ios to size reserves Mike Snitzer
2013-09-12 22:48 ` Mikulas Patocka
2013-09-12 22:24 ` [PATCH 5/7] dm mpath: use dm_get_reserved_rq_based_ios to size mempool Mike Snitzer
2013-09-12 22:48 ` Mikulas Patocka
2013-09-12 22:24 ` [PATCH 6/7] dm: track the maximum number of bios in a cloned request Mike Snitzer
2013-09-12 22:55 ` Mikulas Patocka
2013-09-12 23:09 ` Mike Snitzer
2013-09-12 22:24 ` [PATCH 7/7] dm: optimize clone_rq() when track_peak_rq_based_ios is disabled Mike Snitzer
2013-09-12 23:00 ` Mikulas Patocka
2013-09-12 23:06 ` Mike Snitzer
2013-09-12 23:30 ` Mikulas Patocka
2013-09-12 23:53 ` Mike Snitzer
2013-09-13 4:46 ` Jun'ichi Nomura
2013-09-13 13:04 ` Mike Snitzer
2013-09-13 14:34 ` Mikulas Patocka
2013-09-13 18:59 ` [PATCH v2 0/3] dm: allow mempool and bioset reserves to be tuned Mike Snitzer
2013-09-13 18:59 ` [PATCH v2 1/3] dm: lower bio-based mempool reservation Mike Snitzer
2013-09-13 18:59 ` [PATCH v2 2/3] dm: add reserved_rq_based_ios module parameter Mike Snitzer
2013-09-13 18:59 ` [PATCH v2 3/3] dm: add reserved_bio_based_ios " Mike Snitzer
2013-09-13 19:22 ` [PATCH v2 0/3] dm: allow mempool and bioset reserves to be tuned Mike Snitzer
2013-09-13 20:30 ` Mike Snitzer
2013-09-13 21:08 ` [PATCH v3 " Mike Snitzer
2013-09-13 21:08 ` [PATCH v3 1/3] dm: lower bio-based mempool reservation Mike Snitzer
2013-09-13 21:08 ` [PATCH v3 2/3] dm: add reserved_rq_based_ios module parameter Mike Snitzer
2013-09-13 21:08 ` [PATCH v3 3/3] dm: add reserved_bio_based_ios " Mike Snitzer
2013-09-18 15:10 ` [PATCH v3 0/3] dm: allow mempool and bioset reserves to be tuned Frank Mayhar
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