Re: kernel 3.0: BUG: soft lockup: find_get_pages+0x51/0x110

[Nai Xia]

On Thursday 20 October 2011 03:42:15 Hugh Dickins wrote:
> On Wed, 19 Oct 2011, Linus Torvalds wrote:
> > On Wed, Oct 19, 2011 at 12:43 AM, Mel Gorman <mgorman@xxxxxxx> wrote:
> > >
> > > My vote is with the migration change. While there are occasionally
> > > patches to make migration go faster, I don't consider it a hot path.
> > > mremap may be used intensively by JVMs so I'd loathe to hurt it.
> > 
> > Ok, everybody seems to like that more, and it removes code rather than
> > adds it, so I certainly prefer it too. Pawel, can you test that other
> > patch (to mm/migrate.c) that Hugh posted? Instead of the mremap vma
> > locking patch that you already verified for your setup?
> > 
> > Hugh - that one didn't have a changelog/sign-off, so if you could
> > write that up, and Pawel's testing is successful, I can apply it...
> > Looks like we have acks from both Andrea and Mel.
> 
> Yes, I'm glad to have that input from Andrea and Mel, thank you.
> 
> Here we go.  I can't add a Tested-by since Pawel was reporting on the
> alternative patch, but perhaps you'll be able to add that in later.
> 
> I may have read too much into Pawel's mail, but it sounded like he
> would have expected an eponymous find_get_pages() lockup by now,
> and was pleased that this patch appeared to have cured that.
> 
> I've spent quite a while trying to explain find_get_pages() lockup by
> a missed migration entry, but I just don't see it: I don't expect this
> (or the alternative) patch to do anything to fix that problem.  I won't
> mind if it magically goes away, but I expect we'll need more info from
> the debug patch I sent Justin a couple of days ago.

Hi Hugh, 

Will you please look into my explanation in my reply to Andrea in this thread
and see if it's what you are seeking?


Thanks,

Nai Xia


> 
> Ah, I'd better send the patch separately as
> "[PATCH] mm: fix race between mremap and removing migration entry":
> Pawel's "l" makes my old alpine setup choose quoted printable when
> I reply to your mail.
> 
> Hugh
> 
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@xxxxxxxxxx  For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
> Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
> 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/