linux-mtd.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: Stefani Seibold <stefani@seibold.net>
To: Jamie Lokier <jamie@shareable.org>
Cc: linux-mtd@lists.infradead.org,
	Andrew Morton <akpm@linux-foundation.org>,
	David Woodhouse <dwmw2@infradead.org>,
	"Kreuzer, Michael \(NSN - DE/Ulm\)" <michael.kreuzer@nsn.com>,
	linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [Patch] fix MTD CFI/LPDDR flash driver huge latency bug
Date: Sat, 13 Mar 2010 13:35:44 +0100	[thread overview]
Message-ID: <1268483744.6339.25.camel@wall-e> (raw)
In-Reply-To: <20100312233820.GH6491@shareable.org>

Am Freitag, den 12.03.2010, 23:38 +0000 schrieb Jamie Lokier:
> Andrew Morton wrote:
> > On Sat, 06 Mar 2010 17:48:57 +0100
> > Stefani Seibold <stefani@seibold.net> wrote:
> > 


> > > The patch change all the use of spin_lock operations for xxxx->mutex
> > > into mutex operations, which is exact what the name says and means.
> 
> It would be even better if it also split the critical sections into
> smaller ones with cond_resched() between, so that non-preemptible
> kernels benefit too.
> 

The problem is the memcpy operation which is very slow. A cond_resched
wouldn't help, since the cpu bus is blocked during the transfer of the
word.

  reply	other threads:[~2010-03-13 12:35 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-03-06 16:48 [Patch] fix MTD CFI/LPDDR flash driver huge latency bug Stefani Seibold
2010-03-12 22:23 ` Andrew Morton
2010-03-12 23:38   ` Jamie Lokier
2010-03-13 12:35     ` Stefani Seibold [this message]
2010-03-15  3:03       ` Jamie Lokier
2010-03-15  6:15         ` Stefani Seibold
2010-03-15 14:24           ` Jamie Lokier
2010-03-19  8:29             ` David Woodhouse
2010-03-19  8:40               ` Jamie Lokier
2010-03-13 12:31   ` Stefani Seibold
2010-03-13 11:25     ` Andrew Morton
2010-03-13 17:00       ` Stefani Seibold
  -- strict thread matches above, loose matches on Subject: below --
2010-02-28 17:00 Stefani Seibold

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1268483744.6339.25.camel@wall-e \
    --to=stefani@seibold.net \
    --cc=akpm@linux-foundation.org \
    --cc=dwmw2@infradead.org \
    --cc=jamie@shareable.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mtd@lists.infradead.org \
    --cc=michael.kreuzer@nsn.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).