Re: [PATCH] swsusp: Disable nonboot CPUs before entering platform suspend

[Dave Jones <davej@redhat.com>]

On Thu, Mar 08, 2007 at 12:13:05AM +0100, Rafael J. Wysocki wrote:

 > > > Well, the WARN_ON() in arch/x86_64/kernel/acpi/sleep.c:init_low_mapping()
 > > > triggers every time an SMP x86_64 box is suspended to disk using the platform
 > > > mode (default), which is quite annoying IMHO and users think something wrong is
 > > > going on.  This will probably cause them to report the problem and I'd rather
 > > > like to avoid handling these reports. ;-)
 > > 
 > > Well sure - if patches were always error-free, we'd always apply them
 > > immediately.
 > > 
 > > The question is: is the risk of this patch breaking things exceeded by the
 > > benefit which you describe?
 > 
 > Well, it has survived some testing (http://lkml.org/lkml/2007/3/7/16).  Also,
 > before the code ordering in 2.6.21-rc* we had been running on one CPU
 > here, so I think the risk is small.
 > 
 > We could remove the WARN_ON() as Pavel has just suggested, but first I'd like
 > to know who put it there and why.

It was introduced as part of ..

commit 55b2355eefc2f160246226d4d69fed431173a4d5
Author: Shaohua Li <shaohua.li@intel.com>
Date:   Fri Jun 23 02:04:49 2006 -0700

    [PATCH] don't use flush_tlb_all in suspend time
    
    flush_tlb_all uses on_each_cpu, which will disable/enable interrupt.
    In suspend/resume time, this will make interrupt wrongly enabled.
    
    Signed-off-by: Shaohua Li <shaohua.li@intel.com>
    Cc: Pavel Machek <pavel@ucw.cz>
    Signed-off-by: Andrew Morton <akpm@osdl.org>
    Signed-off-by: Linus Torvalds <torvalds@osdl.org>




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