Messages in this thread | | | Subject | Re: [PATCH 03/15] mm: compaction: introduce isolate_migratepages_range(). | Date | Mon, 30 Jan 2012 13:42:50 +0100 | From | "Michal Nazarewicz" <> |
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> On Thu, Jan 26, 2012 at 10:00:45AM +0100, Marek Szyprowski wrote: >> From: Michal Nazarewicz <mina86@mina86.com> >> @@ -313,7 +316,7 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone, >> } else if (!locked) >> spin_lock_irq(&zone->lru_lock); >> >> - if (!pfn_valid_within(low_pfn)) >> + if (!pfn_valid(low_pfn)) >> continue; >> nr_scanned++; >>
On Mon, 30 Jan 2012 12:24:28 +0100, Mel Gorman <mel@csn.ul.ie> wrote: > This chunk looks unrelated to the rest of the patch. > > I think what you are doing is patching around a bug that CMA exposed > which is very similar to the bug report at > http://www.spinics.net/lists/linux-mm/msg29260.html . Is this true? > > If so, I posted a fix that only calls pfn_valid() when necessary. Can > you check if that works for you and if so, drop this hunk please? If > the patch does not work for you, then this hunk still needs to be > in a separate patch and handled separately as it would also be a fix > for -stable.
I'll actually never encountered this bug myself and CMA is unlikely to expose it, since it always operates on continuous memory regions with no holes.
I've made this change because looking at the code it seemed like this may cause problems in some cases. The crash that you linked to looks like the kind of problem I was thinking about.
I'll drop this hunk and let you resolve this independently of CMA.
-- Best regards, _ _ .o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o ..o | Computer Science, Michał “mina86” Nazarewicz (o o) ooo +----<email/xmpp: mpn@google.com>--------------ooO--(_)--Ooo-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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