linux-kernel - Re: [00/17] Large Blocksize Support V3

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]

Date:	Sat, 28 Apr 2007 02:58:01 -0700
From:	Andrew Morton <akpm@...ux-foundation.org>
To:	Alan Cox <alan@...rguk.ukuu.org.uk>
Cc:	David Chinner <dgc@....com>, Christoph Lameter <clameter@....com>,
	linux-kernel@...r.kernel.org, Mel Gorman <mel@...net.ie>,
	William Lee Irwin III <wli@...omorphy.com>,
	Jens Axboe <jens.axboe@...cle.com>,
	Badari Pulavarty <pbadari@...il.com>,
	Maxim Levitsky <maximlevitsky@...il.com>,
	Nick Piggin <nickpiggin@...oo.com.au>
Subject: Re: [00/17] Large Blocksize Support V3

On Sat, 28 Apr 2007 10:43:28 +0100 Alan Cox <alan@...rguk.ukuu.org.uk> wrote:

> On Fri, 27 Apr 2007 21:56:34 -0700
> Andrew Morton <akpm@...ux-foundation.org> wrote:
> 
> > On Sat, 28 Apr 2007 13:17:40 +1000 David Chinner <dgc@....com> wrote:
> > 
> > > > Fix up your lameo HBA for reads.
> > > 
> > > Where did that come from? You spend 20 lines described the inefficiencies
> > > of the readahead in the page cache and it should be fixed but then you
> > > turn around and say fix the HBA? 
> > 
> > My (repeated) point is that if we populate pagecache with physically-contiguous 4k
> > pages in this manner then bio+block will be able to create much larger SG lists.
> 
> Also remember that even if you do larger pages by using virtual pairs or
> quads of real pages because it helps on some systems you end up needing
> the same sized sglist as before so you don't make anything worse for
> half-assed controllers as you get the same I/O size providing they have
> the minimal 2 or 4 sg list entries (and those that don't are genuinely
> beyond saving and nowdays very rare)
> 

Could you expand on that a bit please?  I don't get it.
-
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/