From: "Kirill A. Shutemov" <kirill@shutemov.name>
To: Christoph Lameter <cl@linux.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
Andrea Arcangeli <aarcange@redhat.com>,
Hugh Dickins <hughd@google.com>,
Dave Hansen <dave.hansen@intel.com>, Mel Gorman <mgorman@suse.de>,
Rik van Riel <riel@redhat.com>, Vlastimil Babka <vbabka@suse.cz>,
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>,
Steve Capper <steve.capper@linaro.org>,
"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@suse.cz>,
Jerome Marchand <jmarchan@redhat.com>,
Sasha Levin <sasha.levin@oracle.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH 04/16] page-flags: define PG_locked behavior on compound pages
Date: Thu, 24 Sep 2015 23:26:20 +0300 [thread overview]
Message-ID: <20150924202620.GA25005@node.dhcp.inet.fi> (raw)
In-Reply-To: <alpine.DEB.2.20.1509241106320.20701@east.gentwo.org>
On Thu, Sep 24, 2015 at 11:08:29AM -0500, Christoph Lameter wrote:
> On Thu, 24 Sep 2015, Kirill A. Shutemov wrote:
>
> > SLUB uses PG_locked as a bit spin locked. IIUC, tail pages should never
> > appear there. VM_BUG_ON() is added to make sure that this assumption is
> > correct.
>
> Correct. However, VM_BUG_ON is superfluous. If there is a tail page there
> then the information in the page will be not as expected (free list
> parameter f.e.) and things will fall apart rapidly with segfaults.
Right. But would it provide any clues on what is going on?
--
Kirill A. Shutemov
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WARNING: multiple messages have this Message-ID (diff)
From: "Kirill A. Shutemov" <kirill@shutemov.name>
To: Christoph Lameter <cl@linux.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
Andrea Arcangeli <aarcange@redhat.com>,
Hugh Dickins <hughd@google.com>,
Dave Hansen <dave.hansen@intel.com>, Mel Gorman <mgorman@suse.de>,
Rik van Riel <riel@redhat.com>, Vlastimil Babka <vbabka@suse.cz>,
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>,
Steve Capper <steve.capper@linaro.org>,
"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@suse.cz>,
Jerome Marchand <jmarchan@redhat.com>,
Sasha Levin <sasha.levin@oracle.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH 04/16] page-flags: define PG_locked behavior on compound pages
Date: Thu, 24 Sep 2015 23:26:20 +0300 [thread overview]
Message-ID: <20150924202620.GA25005@node.dhcp.inet.fi> (raw)
In-Reply-To: <alpine.DEB.2.20.1509241106320.20701@east.gentwo.org>
On Thu, Sep 24, 2015 at 11:08:29AM -0500, Christoph Lameter wrote:
> On Thu, 24 Sep 2015, Kirill A. Shutemov wrote:
>
> > SLUB uses PG_locked as a bit spin locked. IIUC, tail pages should never
> > appear there. VM_BUG_ON() is added to make sure that this assumption is
> > correct.
>
> Correct. However, VM_BUG_ON is superfluous. If there is a tail page there
> then the information in the page will be not as expected (free list
> parameter f.e.) and things will fall apart rapidly with segfaults.
Right. But would it provide any clues on what is going on?
--
Kirill A. Shutemov
next prev parent reply other threads:[~2015-09-24 20:26 UTC|newest]
Thread overview: 101+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-19 17:12 [PATCH 0/3] fix allmodconfig failure of avr32 Sudip Mukherjee
2015-09-19 17:12 ` [PATCH 1/3] avr32: fix build failure Sudip Mukherjee
2015-09-21 6:09 ` Hans-Christian Egtvedt
2015-09-21 6:39 ` Sudip Mukherjee
2015-09-21 7:33 ` Hans-Christian Egtvedt
2015-09-21 8:01 ` Sudip Mukherjee
2015-09-23 15:56 ` Sudip Mukherjee
2015-09-23 17:15 ` Hans-Christian Egtvedt
2015-09-24 10:23 ` Sudip Mukherjee
2015-09-19 17:12 ` [PATCH 2/3] usb: gadget: at91_udc: mention proper dependency Sudip Mukherjee
2015-09-20 16:15 ` Felipe Balbi
2015-09-21 11:10 ` Sudip Mukherjee
2015-09-23 15:52 ` Sudip Mukherjee
2015-09-30 16:04 ` Felipe Balbi
2015-09-30 16:24 ` Sudip Mukherjee
2015-09-30 16:34 ` Nicolas Ferre
2015-09-30 16:53 ` Sudip Mukherjee
2015-09-30 17:12 ` Nicolas Ferre
2015-10-01 12:56 ` Sudip Mukherjee
2015-10-01 16:12 ` Sudip Mukherjee
2015-09-19 17:12 ` [PATCH 3/3] page-flags: rectify forward declaration Sudip Mukherjee
2015-09-21 22:35 ` Andrew Morton
2015-09-22 8:56 ` Sudip Mukherjee
2015-09-24 15:27 ` Sudip Mukherjee
2015-09-24 14:50 ` [PATCH 00/16] Refreshed page-flags patchset Kirill A. Shutemov
2015-09-24 14:50 ` Kirill A. Shutemov
2015-09-24 14:50 ` [PATCH 01/16] page-flags: trivial cleanup for PageTrans* helpers Kirill A. Shutemov
2015-09-24 14:50 ` Kirill A. Shutemov
2015-09-24 15:44 ` Christoph Lameter
2015-09-24 15:44 ` Christoph Lameter
2015-09-24 14:50 ` [PATCH 02/16] page-flags: move code around Kirill A. Shutemov
2015-09-24 14:50 ` Kirill A. Shutemov
2015-09-24 14:50 ` [PATCH 03/16] page-flags: introduce page flags policies wrt compound pages Kirill A. Shutemov
2015-09-24 14:50 ` Kirill A. Shutemov
2015-09-25 12:29 ` Konstantin Khlebnikov
2015-09-25 12:29 ` Konstantin Khlebnikov
2015-09-25 19:13 ` Kirill A. Shutemov
2015-09-25 19:13 ` Kirill A. Shutemov
2015-09-28 10:02 ` Konstantin Khlebnikov
2015-09-28 11:03 ` Kirill A. Shutemov
2015-09-28 11:03 ` Kirill A. Shutemov
2015-09-28 11:48 ` Konstantin Khlebnikov
2015-09-28 11:48 ` Konstantin Khlebnikov
2015-09-28 17:51 ` Kirill A. Shutemov
2015-09-28 17:51 ` Kirill A. Shutemov
2015-09-24 14:50 ` [PATCH 04/16] page-flags: define PG_locked behavior on " Kirill A. Shutemov
2015-09-24 14:50 ` Kirill A. Shutemov
2015-09-24 16:08 ` Christoph Lameter
2015-09-24 16:08 ` Christoph Lameter
2015-09-24 20:26 ` Kirill A. Shutemov [this message]
2015-09-24 20:26 ` Kirill A. Shutemov
2015-09-24 14:50 ` [PATCH 05/16] page-flags: define behavior of FS/IO-related flags " Kirill A. Shutemov
2015-09-24 14:50 ` Kirill A. Shutemov
2015-09-24 14:50 ` [PATCH 06/16] page-flags: define behavior of LRU-related " Kirill A. Shutemov
2015-09-24 14:50 ` Kirill A. Shutemov
2015-09-24 14:50 ` [PATCH 07/16] page-flags: define behavior SL*B-related " Kirill A. Shutemov
2015-09-24 14:50 ` Kirill A. Shutemov
2015-09-24 14:50 ` [PATCH 08/16] page-flags: define behavior of Xen-related " Kirill A. Shutemov
2015-09-24 14:50 ` Kirill A. Shutemov
2015-09-24 14:50 ` [PATCH 09/16] page-flags: define PG_reserved behavior " Kirill A. Shutemov
2015-09-24 14:50 ` Kirill A. Shutemov
2015-09-24 14:50 ` [PATCH 10/16] page-flags: define PG_swapbacked " Kirill A. Shutemov
2015-09-24 14:50 ` Kirill A. Shutemov
2015-09-24 14:50 ` [PATCH 11/16] page-flags: define PG_swapcache " Kirill A. Shutemov
2015-09-24 14:50 ` Kirill A. Shutemov
2015-09-24 14:51 ` [PATCH 12/16] page-flags: define PG_mlocked " Kirill A. Shutemov
2015-09-24 14:51 ` Kirill A. Shutemov
2016-04-18 19:44 ` Sasha Levin
2016-04-18 19:44 ` Sasha Levin
2016-05-18 14:02 ` Kirill A. Shutemov
2016-05-18 14:02 ` Kirill A. Shutemov
2015-09-24 14:51 ` [PATCH 13/16] page-flags: define PG_uncached " Kirill A. Shutemov
2015-09-24 14:51 ` Kirill A. Shutemov
2015-09-24 14:51 ` [PATCH 14/16] page-flags: define PG_uptodate " Kirill A. Shutemov
2015-09-24 14:51 ` Kirill A. Shutemov
2015-09-24 14:51 ` [PATCH 15/16] page-flags: look at head page if the flag is encoded in page->mapping Kirill A. Shutemov
2015-09-24 14:51 ` Kirill A. Shutemov
2015-09-24 14:51 ` [PATCH 16/16] mm: sanitize page->mapping for tail pages Kirill A. Shutemov
2015-09-24 14:51 ` Kirill A. Shutemov
2015-09-25 2:20 ` Jerome Glisse
2015-09-25 2:20 ` Jerome Glisse
2015-09-24 16:13 ` [PATCH 00/16] Refreshed page-flags patchset Christoph Lameter
2015-09-24 16:13 ` Christoph Lameter
2015-09-24 20:25 ` Kirill A. Shutemov
2015-09-24 20:25 ` Kirill A. Shutemov
[not found] <010501d062df$05125160$0f36f420$@alibaba-inc.com>
2015-03-20 7:32 ` [PATCH 04/16] page-flags: define PG_locked behavior on compound pages Hillf Danton
2015-03-20 7:32 ` Hillf Danton
2015-03-20 8:04 ` Kirill A. Shutemov
2015-03-20 8:04 ` Kirill A. Shutemov
-- strict thread matches above, loose matches on Subject: below --
2015-03-19 17:08 [PATCH 00/16] Sanitize usage of ->flags and ->mapping for tail pages Kirill A. Shutemov
2015-03-19 17:08 ` [PATCH 04/16] page-flags: define PG_locked behavior on compound pages Kirill A. Shutemov
2015-03-19 17:08 ` Kirill A. Shutemov
2015-03-27 15:11 ` Mateusz Krawczuk
2015-03-27 15:11 ` Mateusz Krawczuk
2015-03-27 15:13 ` Mateusz Krawczuk
2015-03-27 15:13 ` Mateusz Krawczuk
2015-03-27 15:13 ` Mateusz Krawczuk
2015-03-27 16:37 ` Kirill A. Shutemov
2015-03-27 16:37 ` Kirill A. Shutemov
2015-03-27 16:37 ` Kirill A. Shutemov
2015-07-15 20:20 ` Christoph Lameter
2015-07-15 20:20 ` Christoph Lameter
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