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[195.135.220.15]) by mx.google.com with ESMTPS id 93si10148049wri.328.2018.01.29.02.23.13 for (version=TLS1 cipher=AES128-SHA bits=128/128); Mon, 29 Jan 2018 02:23:14 -0800 (PST) Date: Mon, 29 Jan 2018 10:54:25 +0100 From: Michal Hocko Subject: Re: [PATCH v1] mm: hwpoison: disable memory error handling on 1GB hugepage Message-ID: <20180129095425.GA21609@dhcp22.suse.cz> References: <1517207283-15769-1-git-send-email-n-horiguchi@ah.jp.nec.com> <20180129063054.GA5205@hori1.linux.bs1.fc.nec.co.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180129063054.GA5205@hori1.linux.bs1.fc.nec.co.jp> Sender: owner-linux-mm@kvack.org List-ID: To: Naoya Horiguchi Cc: Andrew Morton , Mike Kravetz , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" On Mon 29-01-18 06:30:55, Naoya Horiguchi wrote: > My apology, I forgot to CC to the mailing lists. > > On Mon, Jan 29, 2018 at 03:28:03PM +0900, Naoya Horiguchi wrote: > > Recently the following BUG was reported: > > > > Injecting memory failure for pfn 0x3c0000 at process virtual address 0x7fe300000000 > > Memory failure: 0x3c0000: recovery action for huge page: Recovered > > BUG: unable to handle kernel paging request at ffff8dfcc0003000 > > IP: gup_pgd_range+0x1f0/0xc20 > > PGD 17ae72067 P4D 17ae72067 PUD 0 > > Oops: 0000 [#1] SMP PTI > > ... > > CPU: 3 PID: 5467 Comm: hugetlb_1gb Not tainted 4.15.0-rc8-mm1-abc+ #3 > > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.3-1.fc25 04/01/2014 > > > > You can easily reproduce this by calling madvise(MADV_HWPOISON) twice on > > a 1GB hugepage. This happens because get_user_pages_fast() is not aware > > of a migration entry on pud that was created in the 1st madvise() event. Do pgd size pages work properly? > > I think that conversion to pud-aligned migration entry is working, > > but other MM code walking over page table isn't prepared for it. > > We need some time and effort to make all this work properly, so > > this patch avoids the reported bug by just disabling error handling > > for 1GB hugepage. Can we also get some documentation which would describe all requirements for HWPoison pages to work properly please? > > Signed-off-by: Naoya Horiguchi Acked-by: Michal Hocko We probably want a backport to stable as well. Although regular process cannot get giga pages easily without admin help it is still not nice to oops like this. > > --- > > include/linux/mm.h | 1 + > > mm/memory-failure.c | 7 +++++++ > > 2 files changed, 8 insertions(+) > > > > diff --git v4.15-rc8-mmotm-2018-01-18-16-31/include/linux/mm.h v4.15-rc8-mmotm-2018-01-18-16-31_patched/include/linux/mm.h > > index 63f7ba1..166864e 100644 > > --- v4.15-rc8-mmotm-2018-01-18-16-31/include/linux/mm.h > > +++ v4.15-rc8-mmotm-2018-01-18-16-31_patched/include/linux/mm.h > > @@ -2607,6 +2607,7 @@ enum mf_action_page_type { > > MF_MSG_POISONED_HUGE, > > MF_MSG_HUGE, > > MF_MSG_FREE_HUGE, > > + MF_MSG_GIGANTIC, > > MF_MSG_UNMAP_FAILED, > > MF_MSG_DIRTY_SWAPCACHE, > > MF_MSG_CLEAN_SWAPCACHE, > > diff --git v4.15-rc8-mmotm-2018-01-18-16-31/mm/memory-failure.c v4.15-rc8-mmotm-2018-01-18-16-31_patched/mm/memory-failure.c > > index d530ac1..c497588 100644 > > --- v4.15-rc8-mmotm-2018-01-18-16-31/mm/memory-failure.c > > +++ v4.15-rc8-mmotm-2018-01-18-16-31_patched/mm/memory-failure.c > > @@ -508,6 +508,7 @@ static const char * const action_page_types[] = { > > [MF_MSG_POISONED_HUGE] = "huge page already hardware poisoned", > > [MF_MSG_HUGE] = "huge page", > > [MF_MSG_FREE_HUGE] = "free huge page", > > + [MF_MSG_GIGANTIC] = "gigantic page", > > [MF_MSG_UNMAP_FAILED] = "unmapping failed page", > > [MF_MSG_DIRTY_SWAPCACHE] = "dirty swapcache page", > > [MF_MSG_CLEAN_SWAPCACHE] = "clean swapcache page", > > @@ -1090,6 +1091,12 @@ static int memory_failure_hugetlb(unsigned long pfn, int trapno, int flags) > > return 0; > > } > > > > + if (hstate_is_gigantic(page_hstate(head))) { > > + action_result(pfn, MF_MSG_GIGANTIC, MF_IGNORED); > > + res = -EBUSY; > > + goto out; > > + } > > + > > if (!hwpoison_user_mappings(p, pfn, trapno, flags, &head)) { > > action_result(pfn, MF_MSG_UNMAP_FAILED, MF_IGNORED); > > res = -EBUSY; > > -- > > 2.7.0 > > > > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: email@kvack.org -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org