Messages in this thread | | | From | "Aneesh Kumar K.V" <> | Subject | Re: [PATCH] mm: fix wrong argument of migrate_huge_pages() in soft_offline_huge_page() | Date | Wed, 18 Jul 2012 13:45:41 +0530 |
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David Rientjes <rientjes@google.com> writes:
> On Tue, 17 Jul 2012, Andrew Morton wrote: > >> > > Commit a6bc32b899223a877f595ef9ddc1e89ead5072b8 ('mm: compaction: introduce >> > > sync-light migration for use by compaction') change declaration of >> > > migrate_pages() and migrate_huge_pages(). >> > > But, it miss changing argument of migrate_huge_pages() >> > > in soft_offline_huge_page(). In this case, we should call with MIGRATE_SYNC. >> > > So change it. >> > > >> > > Additionally, there is mismatch between type of argument and function >> > > declaration for migrate_pages(). So fix this simple case, too. >> > > >> > > Signed-off-by: Joonsoo Kim <js1304@gmail.com> >> > >> > Acked-by: David Rientjes <rientjes@google.com> >> > >> > Should be cc'd to stable for 3.3+. >> >> Well, why? I'm suspecting a switch from MIGRATE_SYNC_LIGHT to >> MIGRATE_SYNC will have no discernable effect. Unless it triggers hitherto >> unknkown about deadlocks... >> >> For a -stable backport we should have a description of the end-user >> visible effects of the bug. This changelog lacked such a description. >> > > I would put this: > > MIGRATE_SYNC_LIGHT will not aggressively attempt to defragment memory when > allocating hugepages for migration with MIGRATE_SYNC_LIGHT, such as not > defragmenting dirty pages, so MADV_SOFT_OFFLINE and > /sys/devices/system/memory/soft_offline_page would be significantly > less successful without this patch.
Is that true with hugetlb pages ? hugetlbfs_migrate_page doesn't seem to use the mode argument at all. We do look at MIGRATE_SYNC if we fail to get page lock, but other than that do we look at mode argument for hugetlb pages ?
-aneesh
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