linux-kernel - Re: [PATCH] hpsa: SCSI driver for HP Smart Array controllers

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20090306182705P.fujita.tomonori@lab.ntt.co.jp>
Date:	Fri, 6 Mar 2009 18:27:21 +0900
From:	FUJITA Tomonori <fujita.tomonori@....ntt.co.jp>
To:	jens.axboe@...cle.com
Cc:	fujita.tomonori@....ntt.co.jp, scameron@...rdog.cca.cpqcorp.net,
	linux-kernel@...r.kernel.org, mike.miller@...com,
	akpm@...ux-foundation.org, linux-scsi@...r.kernel.org,
	coldwell@...hat.com, hare@...ell.com, iss_storagedev@...com
Subject: Re: [PATCH] hpsa: SCSI driver for HP Smart Array controllers

On Fri, 6 Mar 2009 10:21:14 +0100
Jens Axboe <jens.axboe@...cle.com> wrote:

> On Fri, Mar 06 2009, FUJITA Tomonori wrote:
> > On Fri, 6 Mar 2009 09:55:29 +0100
> > Jens Axboe <jens.axboe@...cle.com> wrote:
> > 
> > > > If it's settable at init time, that would probably be enough for
> > > > the vast majority of uses (and more flexible than what we have now)
> > > > and a lot easier to implement.
> > > 
> > > Completely agree, don't waste time implementing something that nobody
> > > will ever touch. The only reason to fiddle with such a setting would be
> > > to increase it, because ios are too small. And even finding out that the
> > > segment limit is the one killing you would take some insight and work
> > > from the user.
> > > 
> > > Just make it Big Enough to cover most cases. 32 is definitely small, 256
> > > entries would get you 1MB ios which I guess is more appropriate.
> > 
> > I guess that the dynamic scheme is overdoing but seems that vendors
> > like some way to configure the sg entry size. The new MPT2SAS driver
> > has SCSI_MPT2SAS_MAX_SGE kernel config option:
> > 
> > http://marc.info/?l=linux-scsi&m=123619290803547&w=2
> > 
> > 
> > The kernel module option for this might be appropriate.
> 
> Dunno, still seems pretty pointless to me. The config option there
> quotes memory consumption as the reason to reduce the number of sg
> entries, however I think that's pretty silly. Additionally, a kernel
> config entry just means that customers will be stuck with a fixed value
> anyway. So I just don't see any merit to doing it that way either.

Yeah, agreed. the kernel config option is pretty pointless. But I'm
not sure that reducing memory consumption is completely pointless.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/