From: "Kirill A. Shutemov" <kirill@shutemov.name>
To: Dave Hansen <dave.hansen@intel.com>, Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
Andrea Arcangeli <aarcange@redhat.com>,
Mel Gorman <mgorman@suse.de>, Rik van Riel <riel@redhat.com>,
Vlastimil Babka <vbabka@suse.cz>,
Christoph Lameter <cl@gentwo.org>,
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>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.de>,
alsa-devel@alsa-project.org
Subject: Re: [PATCH 05/16] page-flags: define behavior of FS/IO-related flags on compound pages
Date: Thu, 19 Mar 2015 22:02:52 +0200 [thread overview]
Message-ID: <20150319200252.GA13348@node.dhcp.inet.fi> (raw)
In-Reply-To: <550B15A0.9090308@intel.com>
On Thu, Mar 19, 2015 at 11:29:52AM -0700, Dave Hansen wrote:
> On 03/19/2015 10:08 AM, Kirill A. Shutemov wrote:
> > The odd exception is PG_dirty: sound uses compound pages and maps them
> > with PTEs. NO_COMPOUND triggers VM_BUG_ON() in set_page_dirty() on
> > handling shared fault. Let's use HEAD for PG_dirty.
>
> Can we get the sound guys to look at this, btw? It seems like an odd
> thing that we probably don't want to keep around, right?
CC: +sound guys
I'm not sure what is right fix here. At the time adding __GFP_COMP was a
fix: see f3d48f0373c1.
Other odd part about __GFP_COMP here is that we have ->_mapcount in tail
pages to be used for both: mapcount of the individual page and for gup
pins. __compound_tail_refcounted() doesn't recognize that we don't need
tail page accounting for these pages.
Hugh, I tried to ask you about the situation several times (last time on
the summit). Any comments?
--
Kirill A. Shutemov
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WARNING: multiple messages have this Message-ID (diff)
From: "Kirill A. Shutemov" <kirill@shutemov.name>
To: Dave Hansen <dave.hansen@intel.com>, Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
Andrea Arcangeli <aarcange@redhat.com>,
Mel Gorman <mgorman@suse.de>, Rik van Riel <riel@redhat.com>,
Vlastimil Babka <vbabka@suse.cz>,
Christoph Lameter <cl@gentwo.org>,
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>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.de>,
alsa-devel@alsa-project.org
Subject: Re: [PATCH 05/16] page-flags: define behavior of FS/IO-related flags on compound pages
Date: Thu, 19 Mar 2015 22:02:52 +0200 [thread overview]
Message-ID: <20150319200252.GA13348@node.dhcp.inet.fi> (raw)
In-Reply-To: <550B15A0.9090308@intel.com>
On Thu, Mar 19, 2015 at 11:29:52AM -0700, Dave Hansen wrote:
> On 03/19/2015 10:08 AM, Kirill A. Shutemov wrote:
> > The odd exception is PG_dirty: sound uses compound pages and maps them
> > with PTEs. NO_COMPOUND triggers VM_BUG_ON() in set_page_dirty() on
> > handling shared fault. Let's use HEAD for PG_dirty.
>
> Can we get the sound guys to look at this, btw? It seems like an odd
> thing that we probably don't want to keep around, right?
CC: +sound guys
I'm not sure what is right fix here. At the time adding __GFP_COMP was a
fix: see f3d48f0373c1.
Other odd part about __GFP_COMP here is that we have ->_mapcount in tail
pages to be used for both: mapcount of the individual page and for gup
pins. __compound_tail_refcounted() doesn't recognize that we don't need
tail page accounting for these pages.
Hugh, I tried to ask you about the situation several times (last time on
the summit). Any comments?
--
Kirill A. Shutemov
next prev parent reply other threads:[~2015-03-19 20:02 UTC|newest]
Thread overview: 119+ messages / expand[flat|nested] mbox.gz Atom feed top
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 ` Kirill A. Shutemov
2015-03-19 17:08 ` [PATCH 01/16] mm: consolidate all page-flags helpers in <linux/page-flags.h> Kirill A. Shutemov
2015-03-19 17:08 ` Kirill A. Shutemov
2015-03-23 0:10 ` Hugh Dickins
2015-03-23 0:10 ` Hugh Dickins
2015-03-19 17:08 ` [PATCH 02/16] page-flags: trivial cleanup for PageTrans* helpers Kirill A. Shutemov
2015-03-19 17:08 ` Kirill A. Shutemov
2015-03-23 0:12 ` Hugh Dickins
2015-03-23 0:12 ` Hugh Dickins
2015-03-19 17:08 ` [PATCH 03/16] page-flags: introduce page flags policies wrt compound pages Kirill A. Shutemov
2015-03-19 17:08 ` Kirill A. Shutemov
2015-03-20 20:35 ` Andrew Morton
2015-03-20 20:35 ` Andrew Morton
2015-03-20 21:34 ` Kirill A. Shutemov
2015-03-20 21:34 ` Kirill A. Shutemov
2015-03-19 17:08 ` [PATCH 04/16] page-flags: define PG_locked behavior on " 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
2015-08-06 4:15 ` page-flags behavior on compound pages: a worry Hugh Dickins
2015-08-06 4:15 ` Hugh Dickins
2015-08-06 15:33 ` Kirill A. Shutemov
2015-08-06 15:33 ` Kirill A. Shutemov
2015-08-06 19:24 ` Hugh Dickins
2015-08-06 19:24 ` Hugh Dickins
2015-08-06 20:45 ` Christoph Lameter
2015-08-06 20:45 ` Christoph Lameter
2015-08-07 14:50 ` Kirill A. Shutemov
2015-08-07 14:50 ` Kirill A. Shutemov
2015-08-07 15:28 ` Christoph Lameter
2015-08-07 15:28 ` Christoph Lameter
2015-08-10 11:09 ` Kirill A. Shutemov
2015-08-10 11:09 ` Kirill A. Shutemov
2015-08-10 13:50 ` Christoph Lameter
2015-08-10 13:50 ` Christoph Lameter
2015-08-07 14:49 ` Kirill A. Shutemov
2015-08-07 14:49 ` Kirill A. Shutemov
2015-08-13 5:10 ` Hugh Dickins
2015-08-13 5:10 ` Hugh Dickins
2015-08-12 14:35 ` Kirill A. Shutemov
2015-08-12 14:35 ` Kirill A. Shutemov
2015-08-12 14:47 ` Vlastimil Babka
2015-08-12 14:47 ` Vlastimil Babka
2015-08-12 21:16 ` Andrew Morton
2015-08-12 21:16 ` Andrew Morton
2015-08-12 22:21 ` Kirill A. Shutemov
2015-08-12 22:21 ` Kirill A. Shutemov
2015-08-13 4:12 ` Hugh Dickins
2015-08-13 4:12 ` Hugh Dickins
2015-03-19 17:08 ` [PATCH 05/16] page-flags: define behavior of FS/IO-related flags on compound pages Kirill A. Shutemov
2015-03-19 17:08 ` Kirill A. Shutemov
2015-03-19 18:29 ` Dave Hansen
2015-03-19 18:29 ` Dave Hansen
2015-03-19 20:02 ` Kirill A. Shutemov [this message]
2015-03-19 20:02 ` Kirill A. Shutemov
2015-03-23 0:02 ` Hugh Dickins
2015-03-23 0:02 ` Hugh Dickins
2015-03-23 12:17 ` Kirill A. Shutemov
2015-03-23 12:17 ` Kirill A. Shutemov
2015-03-24 22:54 ` Hugh Dickins
2015-03-24 22:54 ` Hugh Dickins
2015-03-25 10:23 ` Kirill A. Shutemov
2015-03-25 10:23 ` Kirill A. Shutemov
2015-03-25 18:56 ` Hugh Dickins
2015-03-25 18:56 ` Hugh Dickins
2015-03-19 17:08 ` [PATCH 06/16] page-flags: define behavior of LRU-related " Kirill A. Shutemov
2015-03-19 17:08 ` Kirill A. Shutemov
2015-03-19 17:08 ` [PATCH 07/16] page-flags: define behavior SL*B-related " Kirill A. Shutemov
2015-03-19 17:08 ` Kirill A. Shutemov
2015-03-19 17:08 ` [PATCH 08/16] page-flags: define behavior of Xen-related " Kirill A. Shutemov
2015-03-19 17:08 ` Kirill A. Shutemov
2015-03-19 17:08 ` [PATCH 09/16] page-flags: define PG_reserved behavior " Kirill A. Shutemov
2015-03-19 17:08 ` Kirill A. Shutemov
2020-01-31 15:24 ` Chris Wilson
2020-02-03 15:18 ` Kirill A. Shutemov
2020-02-03 15:24 ` Chris Wilson
2020-02-03 17:10 ` David Hildenbrand
2020-02-03 17:29 ` Christoph Hellwig
2015-03-19 17:08 ` [PATCH 10/16] page-flags: define PG_swapbacked " Kirill A. Shutemov
2015-03-19 17:08 ` Kirill A. Shutemov
2015-03-19 17:08 ` [PATCH 11/16] page-flags: define PG_swapcache " Kirill A. Shutemov
2015-03-19 17:08 ` Kirill A. Shutemov
2015-03-19 17:08 ` [PATCH 12/16] page-flags: define PG_mlocked " Kirill A. Shutemov
2015-03-19 17:08 ` Kirill A. Shutemov
2015-03-19 17:08 ` [PATCH 13/16] page-flags: define PG_uncached " Kirill A. Shutemov
2015-03-19 17:08 ` Kirill A. Shutemov
2015-03-19 17:08 ` [PATCH 14/16] page-flags: define PG_uptodate " Kirill A. Shutemov
2015-03-19 17:08 ` Kirill A. Shutemov
2015-03-19 17:08 ` [PATCH 15/16] page-flags: look on head page if the flag is encoded in page->mapping Kirill A. Shutemov
2015-03-19 17:08 ` Kirill A. Shutemov
2015-03-19 17:08 ` [PATCH 16/16] mm: sanitize page->mapping for tail pages Kirill A. Shutemov
2015-03-19 17:08 ` Kirill A. Shutemov
2015-03-23 0:28 ` [PATCH 00/16] Sanitize usage of ->flags and ->mapping " Hugh Dickins
2015-03-23 0:28 ` Hugh Dickins
2015-03-23 10:04 ` Kirill A. Shutemov
2015-03-23 10:04 ` Kirill A. Shutemov
2015-03-24 23:42 ` Hugh Dickins
2015-03-24 23:42 ` Hugh Dickins
2015-03-25 10:55 ` Kirill A. Shutemov
2015-03-25 10:55 ` Kirill A. Shutemov
2015-03-24 17:39 ` Konstantin Khlebnikov
2015-03-24 17:39 ` Konstantin Khlebnikov
2015-03-24 20:04 ` Kirill A. Shutemov
2015-03-24 20:04 ` Kirill A. Shutemov
2015-07-15 20:20 ` Christoph Lameter
2015-07-15 20:20 ` Christoph Lameter
2015-07-15 21:18 ` Kirill A. Shutemov
2015-07-15 21:18 ` Kirill A. Shutemov
-- strict thread matches above, loose matches on Subject: below --
2015-09-21 22:35 [PATCH 3/3] page-flags: rectify forward declaration Andrew Morton
2015-09-24 14:50 ` [PATCH 00/16] Refreshed page-flags patchset Kirill A. Shutemov
2015-09-24 14:50 ` [PATCH 05/16] page-flags: define behavior of FS/IO-related flags on compound pages Kirill A. Shutemov
2015-09-24 14:50 ` Kirill A. Shutemov
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