From: Aili Yao <yaoaili@kingsoft.com>
To: "Luck, Tony" <tony.luck@intel.com>
Cc: "HORIGUCHI NAOYA(堀口 直也)" <naoya.horiguchi@nec.com>,
"Oscar Salvador" <osalvador@suse.de>,
"david@redhat.com" <david@redhat.com>,
"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
"bp@alien8.de" <bp@alien8.de>,
"tglx@linutronix.de" <tglx@linutronix.de>,
"mingo@redhat.com" <mingo@redhat.com>,
"hpa@zytor.com" <hpa@zytor.com>,
"x86@kernel.org" <x86@kernel.org>,
"linux-edac@vger.kernel.org" <linux-edac@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"yangfeng1@kingsoft.com" <yangfeng1@kingsoft.com>,
yaoaili@kingsoft.com
Subject: Re: [PATCH] mm,hwpoison: return -EBUSY when page already poisoned
Date: Thu, 4 Mar 2021 14:45:24 +0800 [thread overview]
Message-ID: <20210304144524.795872d7@alex-virtual-machine> (raw)
In-Reply-To: <20210304121941.667047c3@alex-virtual-machine>
On Thu, 4 Mar 2021 12:19:41 +0800
Aili Yao <yaoaili@kingsoft.com> wrote:
> On Thu, 4 Mar 2021 10:16:53 +0800
> Aili Yao <yaoaili@kingsoft.com> wrote:
>
> > On Wed, 3 Mar 2021 15:41:35 +0000
> > "Luck, Tony" <tony.luck@intel.com> wrote:
> >
> > > > For error address with sigbus, i think this is not an issue resulted by the patch i post, before my patch, the issue is already there.
> > > > I don't find a realizable way to get the correct address for same reason --- we don't know whether the page mapping is there or not when
> > > > we got to kill_me_maybe(), in some case, we may get it, but there are a lot of parallel issue need to consider, and if failed we have to fallback
> > > > to the error brach again, remaining current code may be an easy option;
> > >
> > > My RFC patch from yesterday removes the uncertainty about whether the page is there or not. After it walks the page
> > > tables we know that the poison page isn't mapped (note that patch is RFC for a reason ... I'm 90% sure that it should
> > > do a bit more that just clear the PRESENT bit).
> > >
> > > So perhaps memory_failure() has queued a SIGBUS for this task, if so, we take it when we return from kill_me_maybe()
>
> And when this happen, the process will receive an SIGBUS with AO level, is it proper as not an AR?
>
> > > If not, we will return to user mode and re-execute the failing instruction ... but because the page is unmapped we will take a #PF
> >
> > Got this, I have some error thoughts here.
> >
> >
> > > The x86 page fault handler will see that the page for this physical address is marked HWPOISON, and it will send the SIGBUS
> > > (just like it does if the page had been removed by an earlier UCNA/SRAO error).
> >
> > if your methods works, should it be like this?
> >
> > 1582 pteval = swp_entry_to_pte(make_hwpoison_entry(subpage));
> > 1583 if (PageHuge(page)) {
> > 1584 hugetlb_count_sub(compound_nr(page), mm);
> > 1585 set_huge_swap_pte_at(mm, address,
> > 1586 pvmw.pte, pteval,
> > 1587 vma_mmu_pagesize(vma));
> > 1588 } else {
> > 1589 dec_mm_counter(mm, mm_counter(page));
> > 1590 set_pte_at(mm, address, pvmw.pte, pteval);
> > 1591 }
> >
> > the page fault check if it's a poison page using is_hwpoison_entry(),
> >
>
> And if it works, does we need some locking mechanism before we call walk_page_range();
> if we lock, does we need to process the blocking interrupted error as other places will do?
>
And another thing:
Do we need a call to flush_tlb_page(vma, address) to make the pte changes into effect?
--
Thanks!
Aili Yao
next prev parent reply other threads:[~2021-03-04 6:47 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20210224151619.67c29731@alex-virtual-machine>
[not found] ` <20210224103105.GA16368@linux>
[not found] ` <20210225114329.4e1a41c6@alex-virtual-machine>
[not found] ` <20210225112818.GA10141@hori.linux.bs1.fc.nec.co.jp>
[not found] ` <20210225113930.GA7227@localhost.localdomain>
[not found] ` <20210225123806.GA15006@hori.linux.bs1.fc.nec.co.jp>
[not found] ` <20210225181542.GA178925@agluck-desk2.amr.corp.intel.com>
[not found] ` <20210226021907.GA27861@hori.linux.bs1.fc.nec.co.jp>
2021-02-26 2:59 ` [PATCH] mm,hwpoison: return -EBUSY when page already poisoned Aili Yao
2021-03-03 3:39 ` Luck, Tony
2021-03-03 3:57 ` Aili Yao
2021-03-03 8:39 ` Aili Yao
2021-03-03 15:41 ` Luck, Tony
2021-03-04 2:16 ` Aili Yao
2021-03-04 4:19 ` Aili Yao
2021-03-04 6:45 ` Aili Yao [this message]
2021-03-04 23:57 ` Luck, Tony
2021-03-05 1:30 ` Aili Yao
2021-03-05 1:36 ` Aili Yao
2021-03-05 22:11 ` Luck, Tony
2021-03-08 6:45 ` HORIGUCHI NAOYA(堀口 直也)
2021-03-08 18:54 ` Luck, Tony
2021-03-08 22:38 ` HORIGUCHI NAOYA(堀口 直也)
2021-03-08 22:55 ` [PATCH] mm/memory-failure: Use a mutex to avoid memory_failure() races Luck, Tony
2021-03-08 23:42 ` HORIGUCHI NAOYA(堀口 直也)
2021-03-09 2:04 ` Aili Yao
2021-03-09 6:04 ` HORIGUCHI NAOYA(堀口 直也)
2021-03-09 6:35 ` [PATCH v2] mm,hwpoison: return -EBUSY when page already poisoned Aili Yao
2021-03-09 8:28 ` HORIGUCHI NAOYA(堀口 直也)
2021-03-09 20:01 ` Luck, Tony
2021-03-10 8:05 ` HORIGUCHI NAOYA(堀口 直也)
2021-03-13 1:55 ` Jue Wang
2021-03-10 8:01 ` Aili Yao
2021-03-09 6:38 ` [PATCH] mm/memory-failure: Use a mutex to avoid memory_failure() races Aili Yao
2021-03-05 15:55 ` [PATCH] mm,hwpoison: return -EBUSY when page already poisoned Luck, Tony
2021-03-10 6:10 ` Aili Yao
2021-03-11 8:55 ` HORIGUCHI NAOYA(堀口 直也)
2021-03-11 11:23 ` Aili Yao
2021-03-11 17:05 ` Luck, Tony
2021-03-12 5:55 ` Aili Yao
2021-03-12 16:29 ` Luck, Tony
2021-03-12 23:48 ` Luck, Tony
2021-03-16 6:42 ` HORIGUCHI NAOYA(堀口 直也)
2021-03-16 7:54 ` Aili Yao
2021-03-17 0:29 ` Luck, Tony
2021-03-17 9:07 ` Aili Yao
2021-03-17 7:48 ` Aili Yao
2021-03-17 8:23 ` Aili Yao
[not found] ` <20210226105250.3a15e35c@alex-virtual-machine>
2021-02-26 17:58 ` Luck, Tony
2021-03-02 4:32 ` Aili Yao
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