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From: Mike Frysinger <vapier@gentoo.org>
To: Pavel Machek <pavel@ucw.cz>, "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: linux-kernel@vger.kernel.org,
	uclinux-dist-devel@blackfin.uclinux.org,
	linux-pm@lists.linux-foundation.org
Subject: freezer: should barriers be smp ?
Date: Wed, 13 Apr 2011 02:14:39 -0400	[thread overview]
Message-ID: <BANLkTi=F-C-vwX4PGGfbkdTBw3OWL-twfg@mail.gmail.com> (raw)

when we suspend/resume Blackfin SMP systems, we notice that the
freezer code runs on multiple cores.  this is of course what you want
-- freeze processes in parallel.  however, the code only uses non-smp
based barriers which causes us problems ... our cores need software
support to keep caches in sync, so our smp barriers do just that.  but
the non-smp barriers do not, and so the frozen/thawed processes
randomly get stuck in the wrong task state.

thinking about it, shouldnt the freezer code be using smp barriers ?
the point is to make sure that the updates are seen across all cores
are not just the current one ?
-mike

             reply	other threads:[~2011-04-13  6:15 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-04-13  6:14 Mike Frysinger [this message]
2011-04-13 20:58 ` freezer: should barriers be smp ? Rafael J. Wysocki
2011-04-13 21:02   ` Mike Frysinger
2011-04-13 21:05     ` Pavel Machek
2011-04-13 21:11       ` [uclinux-dist-devel] " Mike Frysinger
2011-04-13 21:53         ` Rafael J. Wysocki
2011-04-13 22:11           ` [linux-pm] " Alan Stern
2011-04-13 22:34             ` [linux-pm] [uclinux-dist-devel] freezer: should barriers be smp? Rafael J. Wysocki
2011-04-14 14:55               ` Alan Stern
2011-04-14 22:34                 ` Rafael J. Wysocki
2011-04-15 14:32                   ` Alan Stern
2011-04-13 22:22           ` [uclinux-dist-devel] freezer: should barriers be smp ? Mike Frysinger
2011-04-13 22:49             ` Rafael J. Wysocki
2011-04-13 22:53               ` Rafael J. Wysocki
2011-04-13 22:57               ` Mike Frysinger
2011-04-13 23:12                 ` Rafael J. Wysocki
2011-04-14 15:13                 ` [linux-pm] " Alan Stern
2011-04-14 22:40                   ` Rafael J. Wysocki
2011-04-13 22:04         ` [linux-pm] [uclinux-dist-devel] " Alan Stern
2011-04-15 16:29           ` Pavel Machek
2011-04-15 16:33             ` [uclinux-dist-devel] [linux-pm] " Mike Frysinger
2011-04-15 16:57               ` Pavel Machek
2011-04-15 23:11               ` Rafael J. Wysocki
2011-04-15 23:24                 ` Mike Frysinger
2011-04-15 23:30                   ` Rafael J. Wysocki

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