>> >> Fixes: 0f87d9d30f21 ("mm/page_alloc: add an array-based interface to the bulk page allocator") >> >> Reported-by: syzbot+b07d8440edb5f8988eea@xxxxxxxxxxxxxxxxxxxxxxxxx >> >> Suggested-by: Wang Qing <wangqing@xxxxxxxx> >> >> Signed-off-by: Yang Huan <link@xxxxxxxx> >> > >> >https://lore.kernel.org/lkml/20210713152100.10381-2-mgorman@xxxxxxxxxxxxxxxxxxx/ >> >is now part of a series that has being sent to Linus. Hence, the Fixes >> >part is no longer applicable and the patch will no longer be addresing >> >an atomic sleep bug. This patch should be treated as an enhancement >> >> Hi Mel Gorman, thanks for your reply. >> I see the fix patch, it fix this bug by abandon alloc bulk feature when page_owner is set. >> But in my opinion, it can't really fix this bug, it's a circumvention plan. > >Yes, it's a circumvention plan for reasons as laid out in the changelog. > >> >to allow bulk allocations when PAGE_OWNER is set. For that, it should >> >include a note on the performance if PAGE_OWNER is used with either NFS >> >or high-speed networking to justify the additional complexity. >> >> My patch just split the prep_new_page page_gfp into alloc_gfp(for alloc bulk is GFP_ATOMIC, >> for other's no change) and trace page gfp. So, we will not use the error way to get memory. >> So, I think this will not affect alloc bulk performance when page_owner is on(compare with origin patch) but >> can really fix this bug rather than evade. >> And this patch can let alloc bulk feature and page_owner feature work togher >> So, I will send patch again based on the fix patch. > >Your fix should revert the workaround. Also your changelog should note >that in some cases that PAGE_OWNER information will be lost if the >GFP_ATOMIC allocation from bulk allocation context fails. Thanks, I will note that. > >-- >Mel Gorman >SUSE Labs