From: Andrew Morton <akpm@linux-foundation.org>
To: Anton Vorontsov <avorontsov@mvista.com>
Cc: Wolfram Sang <w.sang@pengutronix.de>,
Albert Herranz <albert_herranz@yahoo.es>,
Matt Fleming <matt@console-pimps.org>,
Ben Dooks <ben-linux@fluff.org>, Pierre Ossman <pierre@ossman.eu>,
linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org,
linuxppc-dev@ozlabs.org
Subject: Re: [PATCH 0/8] sdhci: Move real work out of an atomic context
Date: Wed, 21 Jul 2010 14:13:52 -0700 [thread overview]
Message-ID: <20100721141352.d7993493.akpm@linux-foundation.org> (raw)
In-Reply-To: <20100714130728.GA27339@oksana.dev.rtsoft.ru>
On Wed, 14 Jul 2010 17:07:28 +0400
Anton Vorontsov <avorontsov@mvista.com> wrote:
> Hi all,
>
> Currently the sdhci driver does everything in the atomic context.
> And what is worse, PIO transfers are made from the IRQ handler.
>
> This causes huge latencies (up to 120 ms). On some P2020 SOCs,
> DMA and card detection is broken, which means that kernel polls
> for the card via PIO transfers every second. Needless to say
> that this is quite bad.
>
> So, this patch set reworks sdhci code to avoid atomic context,
> almost completely. We only do two device memory operations
> in the atomic context, and all the rest is threaded.
>
> I noticed no throughput drop neither with PIO transfers nor
> with DMA (tested on MPC8569E CPU), while latencies should be
> greatly improved.
>
The patchset looks good to me, but it'd be nice to hear from the other
people who work on this code, please?
WARNING: multiple messages have this Message-ID (diff)
From: Andrew Morton <akpm@linux-foundation.org>
To: Anton Vorontsov <avorontsov@mvista.com>
Cc: Matt Fleming <matt@console-pimps.org>,
Albert Herranz <albert_herranz@yahoo.es>,
linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org,
linuxppc-dev@ozlabs.org, Ben Dooks <ben-linux@fluff.org>,
Pierre Ossman <pierre@ossman.eu>
Subject: Re: [PATCH 0/8] sdhci: Move real work out of an atomic context
Date: Wed, 21 Jul 2010 14:13:52 -0700 [thread overview]
Message-ID: <20100721141352.d7993493.akpm@linux-foundation.org> (raw)
In-Reply-To: <20100714130728.GA27339@oksana.dev.rtsoft.ru>
On Wed, 14 Jul 2010 17:07:28 +0400
Anton Vorontsov <avorontsov@mvista.com> wrote:
> Hi all,
>
> Currently the sdhci driver does everything in the atomic context.
> And what is worse, PIO transfers are made from the IRQ handler.
>
> This causes huge latencies (up to 120 ms). On some P2020 SOCs,
> DMA and card detection is broken, which means that kernel polls
> for the card via PIO transfers every second. Needless to say
> that this is quite bad.
>
> So, this patch set reworks sdhci code to avoid atomic context,
> almost completely. We only do two device memory operations
> in the atomic context, and all the rest is threaded.
>
> I noticed no throughput drop neither with PIO transfers nor
> with DMA (tested on MPC8569E CPU), while latencies should be
> greatly improved.
>
The patchset looks good to me, but it'd be nice to hear from the other
people who work on this code, please?
next prev parent reply other threads:[~2010-07-21 21:14 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-14 13:07 [PATCH 0/8] sdhci: Move real work out of an atomic context Anton Vorontsov
2010-07-14 13:07 ` Anton Vorontsov
2010-07-14 13:07 ` [PATCH 1/8] sdhci: Turn timeout timer into delayed work Anton Vorontsov
2010-07-14 13:07 ` Anton Vorontsov
2010-07-14 13:07 ` [PATCH 2/8] sdhci: Use work structs instead of tasklets Anton Vorontsov
2010-07-14 13:07 ` Anton Vorontsov
2010-07-14 13:08 ` [PATCH 3/8] sdhci: Clear interrupt status register just once Anton Vorontsov
2010-07-14 13:08 ` Anton Vorontsov
2010-07-14 13:08 ` [PATCH 4/8] sdhci: Use threaded IRQ handler Anton Vorontsov
2010-07-14 13:08 ` Anton Vorontsov
2010-07-14 13:08 ` [PATCH 5/8] sdhci: Turn host->lock into a mutex Anton Vorontsov
2010-07-14 13:08 ` Anton Vorontsov
2010-07-14 13:08 ` [PATCH 6/8] sdhci: Get rid of card detect work Anton Vorontsov
2010-07-14 13:08 ` Anton Vorontsov
2010-07-14 13:08 ` [PATCH 7/8] sdhci: Get rid of mdelay()s where it is safe and makes sense Anton Vorontsov
2010-07-14 13:08 ` Anton Vorontsov
2010-07-14 13:08 ` [PATCH 8/8] sdhci: Use jiffies instead of a timeout counter Anton Vorontsov
2010-07-14 13:08 ` Anton Vorontsov
2010-07-15 6:02 ` [PATCH 0/8] sdhci: Move real work out of an atomic context Matt Fleming
2010-07-15 6:02 ` Matt Fleming
2010-07-21 21:13 ` Andrew Morton [this message]
2010-07-21 21:13 ` Andrew Morton
2010-09-07 22:38 ` Andrew Morton
2010-09-07 22:38 ` Andrew Morton
2010-09-08 21:37 ` Chris Ball
2010-09-08 21:37 ` Chris Ball
2010-09-08 21:57 ` Anton Vorontsov
2010-09-08 21:57 ` Anton Vorontsov
2010-09-08 22:05 ` Chris Ball
2010-09-08 22:05 ` Chris Ball
2010-09-08 22:27 ` Anton Vorontsov
2010-09-08 22:27 ` Anton Vorontsov
2010-09-09 2:28 ` Chris Ball
2010-09-09 2:28 ` Chris Ball
2010-09-09 7:15 ` Anton Vorontsov
2010-09-09 7:15 ` Anton Vorontsov
2013-05-24 16:00 Jeremie Samuel
2013-06-13 14:23 ` Jeremie Samuel
2013-06-27 14:46 ` Chris Ball
2013-07-09 15:44 Jeremie Samuel
2013-07-09 15:52 ` Philip Rakity
2013-07-11 8:28 ` Jeremie Samuel
2013-10-16 16:20 Jeremie Samuel
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