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126 Commits (c0c14e6af9ec89479f3ee3895961ef51e97aadd4)
| Author | SHA1 | Message | Date |
|---|---|---|---|
Johannes Weiner
|
a528910e12 |
mm: thrash detection-based file cache sizing
The VM maintains cached filesystem pages on two types of lists. One list holds the pages recently faulted into the cache, the other list holds pages that have been referenced repeatedly on that first list. The idea is to prefer reclaiming young pages over those that have shown to benefit from caching in the past. We call the recently usedbut ultimately was not significantly better than a FIFO policy and still thrashed cache based on eviction speed, rather than actual demand for cache. This patch solves one half of the problem by decoupling the ability to detect working set changes from the inactive list size. By maintaining a history of recently evicted file pages it can detect frequently used pages with an arbitrarily small inactive list size, and subsequently apply pressure on the active list based on actual demand for cache, not just overall eviction speed. Every zone maintains a counter that tracks inactive list aging speed. When a page is evicted, a snapshot of this counter is stored in the now-empty page cache radix tree slot. On refault, the minimum access distance of the page can be assessed, to evaluate whether the page should be part of the active list or not. This fixes the VM's blindness towards working set changes in excess of the inactive list. And it's the foundation to further improve the protection ability and reduce the minimum inactive list size of 50%. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Rik van Riel <riel@redhat.com> Reviewed-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Bob Liu <bob.liu@oracle.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Greg Thelen <gthelen@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Luigi Semenzato <semenzato@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Metin Doslu <metin@citusdata.com> Cc: Michel Lespinasse <walken@google.com> Cc: Ozgun Erdogan <ozgun@citusdata.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roman Gushchin <klamm@yandex-team.ru> Cc: Ryan Mallon <rmallon@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
11 years ago |
|
Johannes Weiner
|
0cd6144aad |
mm + fs: prepare for non-page entries in page cache radix trees
shmem mappings already contain exceptional entries where swap slot information is remembered. To be able to store eviction information for regular page cache, prepare every site dealing with the radix trees directly to handle entries other than pages. The common lookup functions will filter out non-page entries and return NULL for page cache holes, just as before. But provide a raw version of the API which returns non-page entries as well, and switch shmem over to use it. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Rik van Riel <riel@redhat.com> Reviewed-by: Minchan Kim <minchan@kernel.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Bob Liu <bob.liu@oracle.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Greg Thelen <gthelen@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Luigi Semenzato <semenzato@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Metin Doslu <metin@citusdata.com> Cc: Michel Lespinasse <walken@google.com> Cc: Ozgun Erdogan <ozgun@citusdata.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roman Gushchin <klamm@yandex-team.ru> Cc: Ryan Mallon <rmallon@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
11 years ago |
|
David Rientjes
|
668f9abbd4 |
mm: close PageTail race
Commit
|
11 years ago |
|
Sasha Levin
|
309381feae |
mm: dump page when hitting a VM_BUG_ON using VM_BUG_ON_PAGE
Most of the VM_BUG_ON assertions are performed on a page. Usually, when one of these assertions fails we'll get a BUG_ON with a call stack and the registers. I've recently noticed based on the requests to add a small piece of code that dumps the page to various VM_BUG_ON sites that the page dump is quite useful to people debugging issues in mm. This patch adds a VM_BUG_ON_PAGE(cond, page) which beyond doing what VM_BUG_ON() does, also dumps the page before executing the actual BUG_ON. [akpm@linux-foundation.org: fix up includes] Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
11 years ago |
|
Andrew Morton
|
26296ad2df |
mm/swap.c: reorganize put_compound_page()
Tweak it so save a tab stop, make code layout slightly less nutty. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: Pravin Shelar <pshelar@nicira.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Christoph Lameter <cl@linux.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
11 years ago |
|
Andrea Arcangeli
|
3bfcd13ec0 |
mm: hugetlbfs: use __compound_tail_refcounted in __get_page_tail too
Also remove hugetlb.h which isn't needed anymore as PageHeadHuge is handled in mm.h. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: Pravin Shelar <pshelar@nicira.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Christoph Lameter <cl@linux.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
11 years ago |
|
Andrea Arcangeli
|
44518d2b32 |
mm: tail page refcounting optimization for slab and hugetlbfs
This skips the _mapcount mangling for slab and hugetlbfs pages. The main trouble in doing this is to guarantee that PageSlab and PageHeadHuge remains constant for all get_page/put_page run on the tail of slab or hugetlbfs compound pages. Otherwise if they're set during get_page but not set during put_page, the _mapcount of the tail page would underflow. PageHeadHuge will remain true until the compound page is released and enters the buddy allocator so it won't risk to change even if the tail page is the last reference left on the page. PG_slab instead is cleared before the slab frees the head page with put_page, so if the tail pin is released after the slab freed the page, we would have a problem. But in the slab case the tail pin cannot be the last reference left on the page. This is because the slab code is free to reuse the compound page after a kfree/kmem_cache_free without having to check if there's any tail pin left. In turn all tail pins must be always released while the head is still pinned by the slab code and so we know PG_slab will be still set too. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com> Cc: Pravin Shelar <pshelar@nicira.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Christoph Lameter <cl@linux.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
11 years ago |
|
Andrea Arcangeli
|
ebf360f9bb |
mm: hugetlbfs: move the put/get_page slab and hugetlbfs optimization in a faster path
We don't actually need a reference on the head page in the slab and hugetlbfs paths, as long as we add a smp_rmb() which should be faster than get_page_unless_zero. [akpm@linux-foundation.org: fix typo in comment] Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: Pravin Shelar <pshelar@nicira.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Christoph Lameter <cl@linux.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
11 years ago |
|
Andrea Arcangeli
|
27c73ae759 |
mm: hugetlbfs: fix hugetlbfs optimization
Commit
|
11 years ago |
|
Mikulas Patocka
|
8077c0d983 |
bdi: test bdi_init failure
There were two places where return value from bdi_init was not tested. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> |
11 years ago |
|
Chris Metcalf
|
5fbc461636 |
mm: make lru_add_drain_all() selective
make lru_add_drain_all() only selectively interrupt the cpus that have per-cpu free pages that can be drained. This is important in nohz mode where calling mlockall(), for example, otherwise will interrupt every core unnecessarily. This is important on workloads where nohz cores are handling 10 Gb traffic in userspace. Those CPUs do not enter the kernel and place pages into LRU pagevecs and they really, really don't want to be interrupted, or they drop packets on the floor. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Reviewed-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
12 years ago |
|
Khalid Aziz
|
7cb2ef56e6 |
mm: fix aio performance regression for database caused by THP
I am working with a tool that simulates oracle database I/O workload. This tool (orion to be specific - <http://docs.oracle.com/cd/E11882_01/server.112/e16638/iodesign.htm#autoId24>) allocates hugetlbfs pages using shmget() with SHM_HUGETLB flag. It then does aio into these pages from flash disks using various common block sizes used by database. I am looking at performance with two of the most common block sizes - 1M and 64K. aio performance with these two block sizes plunged after Transparent HugePages was introduced in the kernel. Here are performance numbers: pre-THP 2.6.39 3.11-rc5 1M read 8384 MB/s 5629 MB/s 6501 MB/s 64K read 7867 MB/s 4576 MB/s 4251 MB/s I have narrowed the performance impact down to the overheads introduced by THP in __get_page_tail() and put_compound_page() routines. perf top shows >40% of cycles being spent in these two routines. Every time direct I/O to hugetlbfs pages starts, kernel calls get_page() to grab a reference to the pages and calls put_page() when I/O completes to put the reference away. THP introduced significant amount of locking overhead to get_page() and put_page() when dealing with compound pages because hugepages can be split underneath get_page() and put_page(). It added this overhead irrespective of whether it is dealing with hugetlbfs pages or transparent hugepages. This resulted in 20%-45% drop in aio performance when using hugetlbfs pages. Since hugetlbfs pages can not be split, there is no reason to go through all the locking overhead for these pages from what I can see. I added code to __get_page_tail() and put_compound_page() to bypass all the locking code when working with hugetlbfs pages. This improved performance significantly. Performance numbers with this patch: pre-THP 3.11-rc5 3.11-rc5 + Patch 1M read 8384 MB/s 6501 MB/s 8371 MB/s 64K read 7867 MB/s 4251 MB/s 6510 MB/s Performance with 64K read is still lower than what it was before THP, but still a 53% improvement. It does mean there is more work to be done but I will take a 53% improvement for now. Please take a look at the following patch and let me know if it looks reasonable. [akpm@linux-foundation.org: tweak comments] Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com> Cc: Pravin B Shelar <pshelar@nicira.com> Cc: Christoph Lameter <cl@linux.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Rik van Riel <riel@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
12 years ago |
|
Kirill A. Shutemov
|
e180cf806a |
thp, mm: avoid PageUnevictable on active/inactive lru lists
active/inactive lru lists can contain unevicable pages (i.e. ramfs pages
that have been placed on the LRU lists when first allocated), but these
pages must not have PageUnevictable set - otherwise shrink_[in]active_list
goes crazy:
kernel BUG at /home/space/kas/git/public/linux-next/mm/vmscan.c:1122!
1090 static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
1091 struct lruvec *lruvec, struct list_head *dst,
1092 unsigned long *nr_scanned, struct scan_control *sc,
1093 isolate_mode_t mode, enum lru_list lru)
1094 {
...
1108 switch (__isolate_lru_page(page, mode)) {
1109 case 0:
...
1116 case -EBUSY:
...
1121 default:
1122 BUG();
1123 }
1124 }
...
1130 }
__isolate_lru_page() returns EINVAL for PageUnevictable(page).
For lru_add_page_tail(), it means we should not set PageUnevictable()
for tail pages unless we're sure that it will go to LRU_UNEVICTABLE.
Let's just copy PG_active and PG_unevictable from head page in
__split_huge_page_refcount(), it will simplify lru_add_page_tail().
This will fix one more bug in lru_add_page_tail(): if
page_evictable(page_tail) is false and PageLRU(page) is true, page_tail
will go to the same lru as page, but nobody cares to sync page_tail
active/inactive state with page. So we can end up with inactive page on
active lru. The patch will fix it as well since we copy PG_active from
head page.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
12 years ago |
|
Naoya Horiguchi
|
ef2a2cbdda |
mm/swap.c: clear PageActive before adding pages onto unevictable list
As a result of commit
|
12 years ago |
|
Mel Gorman
|
c53954a092 |
mm: remove lru parameter from __lru_cache_add and lru_cache_add_lru
Similar to __pagevec_lru_add, this patch removes the LRU parameter from __lru_cache_add and lru_cache_add_lru as the caller does not control the exact LRU the page gets added to. lru_cache_add_lru gets renamed to lru_cache_add the name is silly without the lru parameter. With the parameter removed, it is required that the caller indicate if they want the page added to the active or inactive list by setting or clearing PageActive respectively. [akpm@linux-foundation.org: Suggested the patch] [gang.chen@asianux.com: fix used-unintialized warning] Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Chen Gang <gang.chen@asianux.com> Cc: Jan Kara <jack@suse.cz> Cc: Rik van Riel <riel@redhat.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Alexey Lyahkov <alexey.lyashkov@gmail.com> Cc: Andrew Perepechko <anserper@ya.ru> Cc: Robin Dong <sanbai@taobao.com> Cc: Theodore Tso <tytso@mit.edu> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Bernd Schubert <bernd.schubert@fastmail.fm> Cc: David Howells <dhowells@redhat.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
12 years ago |
|
Mel Gorman
|
a0b8cab3b9 |
mm: remove lru parameter from __pagevec_lru_add and remove parts of pagevec API
Now that the LRU to add a page to is decided at LRU-add time, remove the misleading lru parameter from __pagevec_lru_add. A consequence of this is that the pagevec_lru_add_file, pagevec_lru_add_anon and similar helpers are misleading as the caller no longer has direct control over what LRU the page is added to. Unused helpers are removed by this patch and existing users of pagevec_lru_add_file() are converted to use lru_cache_add_file() directly and use the per-cpu pagevecs instead of creating their own pagevec. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Alexey Lyahkov <alexey.lyashkov@gmail.com> Cc: Andrew Perepechko <anserper@ya.ru> Cc: Robin Dong <sanbai@taobao.com> Cc: Theodore Tso <tytso@mit.edu> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Bernd Schubert <bernd.schubert@fastmail.fm> Cc: David Howells <dhowells@redhat.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
12 years ago |
|
Mel Gorman
|
059285a25f |
mm: activate !PageLRU pages on mark_page_accessed if page is on local pagevec
If a page is on a pagevec then it is !PageLRU and mark_page_accessed()
may fail to move a page to the active list as expected. Now that the
LRU is selected at LRU drain time, mark pages PageActive if they are on
the local pagevec so it gets moved to the correct list at LRU drain
time. Using a debugging patch it was found that for a simple git
checkout based workload that pages were never added to the active file
list in practice but with this patch applied they are.
before after
LRU Add Active File 0 750583
LRU Add Active Anon 2640587 2702818
LRU Add Inactive File 8833662 8068353
LRU Add Inactive Anon 207 200
Note that only pages on the local pagevec are considered on purpose. A
!PageLRU page could be in the process of being released, reclaimed,
migrated or on a remote pagevec that is currently being drained.
Marking it PageActive is vunerable to races where PageLRU and Active
bits are checked at the wrong time. Page reclaim will trigger
VM_BUG_ONs but depending on when the race hits, it could also free a
PageActive page to the page allocator and trigger a bad_page warning.
Similarly a potential race exists between a per-cpu drain on a pagevec
list and an activation on a remote CPU.
lru_add_drain_cpu
__pagevec_lru_add
lru = page_lru(page);
mark_page_accessed
if (PageLRU(page))
activate_page
else
SetPageActive
SetPageLRU(page);
add_page_to_lru_list(page, lruvec, lru);
In this case a PageActive page is added to the inactivate list and later
the inactive/active stats will get skewed. While the PageActive checks
in vmscan could be removed and potentially dealt with, a skew in the
statistics would be very difficult to detect. Hence this patch deals
just with the common case where a page being marked accessed has just
been added to the local pagevec.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Jan Kara <jack@suse.cz>
Cc: Rik van Riel <riel@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Alexey Lyahkov <alexey.lyashkov@gmail.com>
Cc: Andrew Perepechko <anserper@ya.ru>
Cc: Robin Dong <sanbai@taobao.com>
Cc: Theodore Tso <tytso@mit.edu>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Bernd Schubert <bernd.schubert@fastmail.fm>
Cc: David Howells <dhowells@redhat.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
12 years ago |
|
Mel Gorman
|
13f7f78981 |
mm: pagevec: defer deciding which LRU to add a page to until pagevec drain time
mark_page_accessed() cannot activate an inactive page that is located on an inactive LRU pagevec. Hints from filesystems may be ignored as a result. In preparation for fixing that problem, this patch removes the per-LRU pagevecs and leaves just one pagevec. The final LRU the page is added to is deferred until the pagevec is drained. This means that fewer pagevecs are available and potentially there is greater contention on the LRU lock. However, this only applies in the case where there is an almost perfect mix of file, anon, active and inactive pages being added to the LRU. In practice I expect that we are adding stream of pages of a particular time and that the changes in contention will barely be measurable. Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Jan Kara <jack@suse.cz> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Alexey Lyahkov <alexey.lyashkov@gmail.com> Cc: Andrew Perepechko <anserper@ya.ru> Cc: Robin Dong <sanbai@taobao.com> Cc: Theodore Tso <tytso@mit.edu> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Bernd Schubert <bernd.schubert@fastmail.fm> Cc: David Howells <dhowells@redhat.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
12 years ago |
|
Mel Gorman
|
c6286c9839 |
mm: add tracepoints for LRU activation and insertions
Andrew Perepechko reported a problem whereby pages are being prematurely evicted as the mark_page_accessed() hint is ignored for pages that are currently on a pagevec -- http://www.spinics.net/lists/linux-ext4/msg37340.html . Alexey Lyahkov and Robin Dong have also reported problems recently that could be due to hot pages reaching the end of the inactive list too quickly and be reclaimed. Rather than addressing this on a per-filesystem basis, this series aims to fix the mark_page_accessed() interface by deferring what LRU a page is added to pagevec drain time and allowing mark_page_accessed() to call SetPageActive on a pagevec page. Patch 1 adds two tracepoints for LRU page activation and insertion. Using these processes it's possible to build a model of pages in the LRU that can be processed offline. Patch 2 defers making the decision on what LRU to add a page to until when the pagevec is drained. Patch 3 searches the local pagevec for pages to mark PageActive on mark_page_accessed. The changelog explains why only the local pagevec is examined. Patches 4 and 5 tidy up the API. postmark, a dd-based test and fs-mark both single and threaded mode were run but none of them showed any performance degradation or gain as a result of the patch. Using patch 1, I built a *very* basic model of the LRU to examine offline what the average age of different page types on the LRU were in milliseconds. Of course, capturing the trace distorts the test as it's written to local disk but it does not matter for the purposes of this test. The average age of pages in milliseconds were vanilla deferdrain Average age mapped anon: 1454 1250 Average age mapped file: 127841 155552 Average age unmapped anon: 85 235 Average age unmapped file: 73633 38884 Average age unmapped buffers: 74054 116155 The LRU activity was mostly files which you'd expect for a dd-based workload. Note that the average age of buffer pages is increased by the series and it is expected this is due to the fact that the buffer pages are now getting added to the active list when drained from the pagevecs. Note that the average age of the unmapped file data is decreased as they are still added to the inactive list and are reclaimed before the buffers. There is no guarantee this is a universal win for all workloads and it would be nice if the filesystem people gave some thought as to whether this decision is generally a win or a loss. This patch: Using these tracepoints it is possible to model LRU activity and the average residency of pages of different types. This can be used to debug problems related to premature reclaim of pages of particular types. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Alexey Lyahkov <alexey.lyashkov@gmail.com> Cc: Andrew Perepechko <anserper@ya.ru> Cc: Robin Dong <sanbai@taobao.com> Cc: Theodore Tso <tytso@mit.edu> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Bernd Schubert <bernd.schubert@fastmail.fm> Cc: David Howells <dhowells@redhat.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
12 years ago |
|
Kent Overstreet
|
a27bb332c0 |
aio: don't include aio.h in sched.h
Faster kernel compiles by way of fewer unnecessary includes. [akpm@linux-foundation.org: fix fallout] [akpm@linux-foundation.org: fix build] Signed-off-by: Kent Overstreet <koverstreet@google.com> Cc: Zach Brown <zab@redhat.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jens Axboe <axboe@kernel.dk> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Benjamin LaHaise <bcrl@kvack.org> Reviewed-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
12 years ago |
|
Shaohua Li
|
5bc7b8aca9 |
mm: thp: add split tail pages to shrink page list in page reclaim
In page reclaim, huge page is split. split_huge_page() adds tail pages to LRU list. Since we are reclaiming a huge page, it's better we reclaim all subpages of the huge page instead of just the head page. This patch adds split tail pages to shrink page list so the tail pages can be reclaimed soon. Before this patch, run a swap workload: thp_fault_alloc 3492 thp_fault_fallback 608 thp_collapse_alloc 6 thp_collapse_alloc_failed 0 thp_split 916 With this patch: thp_fault_alloc 4085 thp_fault_fallback 16 thp_collapse_alloc 90 thp_collapse_alloc_failed 0 thp_split 1272 fallback allocation is reduced a lot. [akpm@linux-foundation.org: fix CONFIG_SWAP=n build] Signed-off-by: Shaohua Li <shli@fusionio.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Minchan Kim <minchan@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
12 years ago |
|
Shaohua Li
|
33806f06da |
swap: make each swap partition have one address_space
When I use several fast SSD to do swap, swapper_space.tree_lock is heavily contended. This makes each swap partition have one address_space to reduce the lock contention. There is an array of address_space for swap. The swap entry type is the index to the array. In my test with 3 SSD, this increases the swapout throughput 20%. [akpm@linux-foundation.org: revert unneeded change to __add_to_swap_cache] Signed-off-by: Shaohua Li <shli@fusionio.com> Cc: Hugh Dickins <hughd@google.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
12 years ago |
|
Hugh Dickins
|
39b5f29ac1 |
mm: remove vma arg from page_evictable
page_evictable(page, vma) is an irritant: almost all its callers pass NULL for vma. Remove the vma arg and use mlocked_vma_newpage(vma, page) explicitly in the couple of places it's needed. But in those places we don't even need page_evictable() itself! They're dealing with a freshly allocated anonymous page, which has no "mapping" and cannot be mlocked yet. Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Cc: Rik van Riel <riel@redhat.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michel Lespinasse <walken@google.com> Cc: Ying Han <yinghan@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
12 years ago |
|
Robin Dong
|
d741c9cdee |
mm: fix nonuniform page status when writing new file with small buffer
When writing a new file with 2048 bytes buffer, such as write(fd, buffer, 2048), it will call generic_perform_write() twice for every page: write_begin mark_page_accessed(page) write_end write_begin mark_page_accessed(page) write_end Pages 1-13 will be added to lru-pvecs in write_begin() and will *NOT* be added to active_list even they have be accessed twice because they are not PageLRU(page). But when page 14th comes, all pages in lru-pvecs will be moved to inactive_list (by __lru_cache_add() ) in first write_begin(), now page 14th *is* PageLRU(page). And after second write_end() only page 14th will be in active_list. In Hadoop environment, we do comes to this situation: after writing a file, we find out that only 14th, 28th, 42th... page are in active_list and others in inactive_list. Now kswapd works, shrinks the inactive_list, the file only have 14th, 28th...pages in memory, the readahead request size will be broken to only 52k (13*4k), system's performance falls dramatically. This problem can also replay by below steps (the machine has 8G memory): 1. dd if=/dev/zero of=/test/file.out bs=1024 count=1048576 2. cat another 7.5G file to /dev/null 3. vmtouch -m 1G -v /test/file.out, it will show: /test/file.out [oooooooooooooooooooOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO] 187847/262144 the 'o' means same pages are in memory but same are not. The solution for this problem is simple: the 14th page should be added to lru_add_pvecs before mark_page_accessed() just as other pages. [akpm@linux-foundation.org: tweak comment] [akpm@linux-foundation.org: grab better comment from the v3 patch] Signed-off-by: Robin Dong <sanbai@taobao.com> Reviewed-by: Minchan Kim <minchan@kernel.org> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Reviewed-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
12 years ago |
|
Mel Gorman
|
5a178119b0 |
mm: add support for direct_IO to highmem pages
The patch "mm: add support for a filesystem to activate swap files and use direct_IO for writing swap pages" added support for using direct_IO to write swap pages but it is insufficient for highmem pages. To support highmem pages, this patch kmaps() the page before calling the direct_IO() handler. As direct_IO deals with virtual addresses an additional helper is necessary for get_kernel_pages() to lookup the struct page for a kmap virtual address. Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: David S. Miller <davem@davemloft.net> Cc: Eric B Munson <emunson@mgebm.net> Cc: Eric Paris <eparis@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Xiaotian Feng <dfeng@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
13 years ago |
|
Mel Gorman
|
18022c5d86 |
mm: add get_kernel_page[s] for pinning of kernel addresses for I/O
This patch adds two new APIs get_kernel_pages() and get_kernel_page() that may be used to pin a vector of kernel addresses for IO. The initial user is expected to be NFS for allowing pages to be written to swap using aops->direct_IO(). Strictly speaking, swap-over-NFS only needs to pin one page for IO but it makes sense to express the API in terms of a vector and add a helper for pinning single pages. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: David S. Miller <davem@davemloft.net> Cc: Eric B Munson <emunson@mgebm.net> Cc: Eric Paris <eparis@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Xiaotian Feng <dfeng@redhat.com> Cc: Mark Salter <msalter@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
13 years ago |
|
Hugh Dickins
|
fa9add641b |
mm/memcg: apply add/del_page to lruvec
Take lruvec further: pass it instead of zone to add_page_to_lru_list() and del_page_from_lru_list(); and pagevec_lru_move_fn() pass lruvec down to its target functions. This cleanup eliminates a swathe of cruft in memcontrol.c, including mem_cgroup_lru_add_list(), mem_cgroup_lru_del_list() and mem_cgroup_lru_move_lists() - which never actually touched the lists. In their place, mem_cgroup_page_lruvec() to decide the lruvec, previously a side-effect of add, and mem_cgroup_update_lru_size() to maintain the lru_size stats. Whilst these are simplifications in their own right, the goal is to bring the evaluation of lruvec next to the spin_locking of the lrus, in preparation for a future patch. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
13 years ago |
|
Hugh Dickins
|
89abfab133 |
mm/memcg: move reclaim_stat into lruvec
With mem_cgroup_disabled() now explicit, it becomes clear that the zone_reclaim_stat structure actually belongs in lruvec, per-zone when memcg is disabled but per-memcg per-zone when it's enabled. We can delete mem_cgroup_get_reclaim_stat(), and change update_page_reclaim_stat() to update just the one set of stats, the one which get_scan_count() will actually use. Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: Glauber Costa <glommer@parallels.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
13 years ago |
|
Pravin B Shelar
|
5bf5f03c27 |
mm: fix slab->page flags corruption
Transparent huge pages can change page->flags (PG_compound_lock) without taking Slab lock. Since THP can not break slab pages we can safely access compound page without taking compound lock. Specifically this patch fixes a race between compound_unlock() and slab functions which perform page-flags updates. This can occur when get_page()/put_page() is called on a page from slab. [akpm@linux-foundation.org: tweak comment text, fix comment layout, fix label indenting] Reported-by: Amey Bhide <abhide@nicira.com> Signed-off-by: Pravin B Shelar <pshelar@nicira.com> Reviewed-by: Christoph Lameter <cl@linux.com> Acked-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
13 years ago |
|
Konstantin Khlebnikov
|
f0cb3c76ae |
mm: drain percpu lru add/rotate page-vectors on cpu hot-unplug
This cpu hotplug hook was accidentally removed in commit
|
13 years ago |
|
Hugh Dickins
|
7512102cf6 |
memcg: fix GPF when cgroup removal races with last exit
When moving tasks from old memcg (with move_charge_at_immigrate on new memcg), followed by removal of old memcg, hit General Protection Fault in mem_cgroup_lru_del_list() (called from release_pages called from free_pages_and_swap_cache from tlb_flush_mmu from tlb_finish_mmu from exit_mmap from mmput from exit_mm from do_exit). Somewhat reproducible, takes a few hours: the old struct mem_cgroup has been freed and poisoned by SLAB_DEBUG, but mem_cgroup_lru_del_list() is still trying to update its stats, and take page off lru before freeing. A task, or a charge, or a page on lru: each secures a memcg against removal. In this case, the last task has been moved out of the old memcg, and it is exiting: anonymous pages are uncharged one by one from the memcg, as they are zapped from its pagetables, so the charge gets down to 0; but the pages themselves are queued in an mmu_gather for freeing. Most of those pages will be on lru (and force_empty is careful to lru_add_drain_all, to add pages from pagevec to lru first), but not necessarily all: perhaps some have been isolated for page reclaim, perhaps some isolated for other reasons. So, force_empty may find no task, no charge and no page on lru, and let the removal proceed. There would still be no problem if these pages were immediately freed; but typically (and the put_page_testzero protocol demands it) they have to be added back to lru before they are found freeable, then removed from lru and freed. We don't see the issue when adding, because the mem_cgroup_iter() loops keep their own reference to the memcg being scanned; but when it comes to mem_cgroup_lru_del_list(). I believe this was not an issue in v3.2: there, PageCgroupAcctLRU and PageCgroupUsed flags were used (like a trick with mirrors) to deflect view of pc->mem_cgroup to the stable root_mem_cgroup when neither set. |
13 years ago |
|
Hugh Dickins
|
b9980cdcf2 |
mm: fix UP THP spin_is_locked BUGs
Fix CONFIG_TRANSPARENT_HUGEPAGE=y CONFIG_SMP=n CONFIG_DEBUG_VM=y CONFIG_DEBUG_SPINLOCK=n kernel: spin_is_locked() is then always false, and so triggers some BUGs in Transparent HugePage codepaths. asm-generic/bug.h mentions this problem, and provides a WARN_ON_SMP(x); but being too lazy to add VM_BUG_ON_SMP, BUG_ON_SMP, WARN_ON_SMP_ONCE, VM_WARN_ON_SMP_ONCE, just test NR_CPUS != 1 in the existing VM_BUG_ONs. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
13 years ago |
|
Hugh Dickins
|
1c1c53d43b |
mm: remove del_page_from_lru, add page_off_lru
del_page_from_lru() repeats del_page_from_lru_list(), also working out which LRU the page was on, clearing the relevant bits. Decouple those functions: remove del_page_from_lru() and add page_off_lru(). Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
13 years ago |
|
Hugh Dickins
|
4d06f382c7 |
mm: no blank line after EXPORT_SYMBOL in swap.c
checkpatch rightly protests WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable so fix the five offenders in mm/swap.c. Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
13 years ago |
|
Hugh Dickins
|
5095ae8375 |
mm: fewer underscores in ____pagevec_lru_add
What's so special about ____pagevec_lru_add() that it needs four leading underscores? Nothing, it just helped to distinguish from __pagevec_lru_add() in 2.6.28 development. Cut two leading underscores. Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
13 years ago |
|
Hugh Dickins
|
2bcf887963 |
mm: take pagevecs off reclaim stack
Replace pagevecs in putback_lru_pages() and move_active_pages_to_lru() by lists of pages_to_free: then apply Konstantin Khlebnikov's free_hot_cold_page_list() to them instead of pagevec_release(). Which simplifies the flow (no need to drop and retake lock whenever pagevec fills up) and reduces stale addresses in stack backtraces (which often showed through the pagevecs); but more importantly, removes another 120 bytes from the deepest stacks in page reclaim. Although I've not recently seen an actual stack overflow here with a vanilla kernel, move_active_pages_to_lru() has often featured in deep backtraces. However, free_hot_cold_page_list() does not handle compound pages (nor need it: a Transparent HugePage would have been split by the time it reaches the call in shrink_page_list()), but it is possible for putback_lru_pages() or move_active_pages_to_lru() to be left holding the last reference on a THP, so must exclude the unlikely compound case before putting on pages_to_free. Remove pagevec_strip(), its work now done in move_active_pages_to_lru(). The pagevec in scan_mapping_unevictable_pages() remains in mm/vmscan.c, but that is never on the reclaim path, and cannot be replaced by a list. Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
13 years ago |
|
Hugh Dickins
|
12d2710786 |
memcg: fix split_huge_page_refcounts()
This patch started off as a cleanup: __split_huge_page_refcounts() has to cope with two scenarios, when the hugepage being split is already on LRU, and when it is not; but why does it have to split that accounting across three different sites? Consolidate it in lru_add_page_tail(), handling evictable and unevictable alike, and use standard add_page_to_lru_list() when accounting is needed (when the head is not yet on LRU). But a recent regression in -next, I guess the removal of PageCgroupAcctLRU test from mem_cgroup_split_huge_fixup(), makes this now a necessary fix: under load, the MEM_CGROUP_ZSTAT count was wrapping to a huge number, messing up reclaim calculations and causing a freeze at rmdir of cgroup. Add a VM_BUG_ON to mem_cgroup_lru_del_list() when we're about to wrap that count - this has not been the only such incident. Document that lru_add_page_tail() is for Transparent HugePages by #ifdef around it. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
13 years ago |
|
Shaohua Li
|
45676885b7 |
thp: improve order in lru list for split huge page
Put the tail subpages of an isolated hugepage under splitting in the lru reclaim head as they supposedly should be isolated too next. Queues the subpages in physical order in the lru for non isolated hugepages under splitting. That might provide some theoretical cache benefit to the buddy allocator later. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
13 years ago |
|
Johannes Weiner
|
925b7673cc |
mm: make per-memcg LRU lists exclusive
Now that all code that operated on global per-zone LRU lists is converted to operate on per-memory cgroup LRU lists instead, there is no reason to keep the double-LRU scheme around any longer. The pc->lru member is removed and page->lru is linked directly to the per-memory cgroup LRU lists, which removes two pointers from a descriptor that exists for every page frame in the system. Signed-off-by: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Ying Han <yinghan@google.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Greg Thelen <gthelen@google.com> Cc: Michel Lespinasse <walken@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
13 years ago |
|
Johannes Weiner
|
6290df5458 |
mm: collect LRU list heads into struct lruvec
Having a unified structure with a LRU list set for both global zones and per-memcg zones allows to keep that code simple which deals with LRU lists and does not care about the container itself. Once the per-memcg LRU lists directly link struct pages, the isolation function and all other list manipulations are shared between the memcg case and the global LRU case. Signed-off-by: Johannes Weiner <jweiner@redhat.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Ying Han <yinghan@google.com> Cc: Greg Thelen <gthelen@google.com> Cc: Michel Lespinasse <walken@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
13 years ago |
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Konstantin Khlebnikov
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cc59850ef9 |
mm: add free_hot_cold_page_list() helper
This patch adds helper free_hot_cold_page_list() to free list of 0-order pages. It frees pages directly from list without temporary page-vector. It also calls trace_mm_pagevec_free() to simulate pagevec_free() behaviour. bloat-o-meter: add/remove: 1/1 grow/shrink: 1/3 up/down: 267/-295 (-28) function old new delta free_hot_cold_page_list - 264 +264 get_page_from_freelist 2129 2132 +3 __pagevec_free 243 239 -4 split_free_page 380 373 -7 release_pages 606 510 -96 free_page_list 188 - -188 Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
13 years ago |
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Andrea Arcangeli
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70b50f94f1 |
mm: thp: tail page refcounting fix
Michel while working on the working set estimation code, noticed that calling get_page_unless_zero() on a random pfn_to_page(random_pfn) wasn't safe, if the pfn ended up being a tail page of a transparent hugepage under splitting by __split_huge_page_refcount(). He then found the problem could also theoretically materialize with page_cache_get_speculative() during the speculative radix tree lookups that uses get_page_unless_zero() in SMP if the radix tree page is freed and reallocated and get_user_pages is called on it before page_cache_get_speculative has a chance to call get_page_unless_zero(). So the best way to fix the problem is to keep page_tail->_count zero at all times. This will guarantee that get_page_unless_zero() can never succeed on any tail page. page_tail->_mapcount is guaranteed zero and is unused for all tail pages of a compound page, so we can simply account the tail page references there and transfer them to tail_page->_count in __split_huge_page_refcount() (in addition to the head_page->_mapcount). While debugging this s/_count/_mapcount/ change I also noticed get_page is called by direct-io.c on pages returned by get_user_pages. That wasn't entirely safe because the two atomic_inc in get_page weren't atomic. As opposed to other get_user_page users like secondary-MMU page fault to establish the shadow pagetables would never call any superflous get_page after get_user_page returns. It's safer to make get_page universally safe for tail pages and to use get_page_foll() within follow_page (inside get_user_pages()). get_page_foll() is safe to do the refcounting for tail pages without taking any locks because it is run within PT lock protected critical sections (PT lock for pte and page_table_lock for pmd_trans_huge). The standard get_page() as invoked by direct-io instead will now take the compound_lock but still only for tail pages. The direct-io paths are usually I/O bound and the compound_lock is per THP so very finegrined, so there's no risk of scalability issues with it. A simple direct-io benchmarks with all lockdep prove locking and spinlock debugging infrastructure enabled shows identical performance and no overhead. So it's worth it. Ideally direct-io should stop calling get_page() on pages returned by get_user_pages(). The spinlock in get_page() is already optimized away for no-THP builds but doing get_page() on tail pages returned by GUP is generally a rare operation and usually only run in I/O paths. This new refcounting on page_tail->_mapcount in addition to avoiding new RCU critical sections will also allow the working set estimation code to work without any further complexity associated to the tail page refcounting with THP. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reported-by: Michel Lespinasse <walken@google.com> Reviewed-by: Michel Lespinasse <walken@google.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: <stable@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
13 years ago |
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Paul Gortmaker
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b95f1b31b7 |
mm: Map most files to use export.h instead of module.h
The files changed within are only using the EXPORT_SYMBOL macro variants. They are not using core modular infrastructure and hence don't need module.h but only the export.h header. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
13 years ago |
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Shaohua Li
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eb709b0d06 |
mm: batch activate_page() to reduce lock contention
The zone->lru_lock is heavily contented in workload where activate_page()
is frequently used. We could do batch activate_page() to reduce the lock
contention. The batched pages will be added into zone list when the pool
is full or page reclaim is trying to drain them.
For example, in a 4 socket 64 CPU system, create a sparse file and 64
processes, processes shared map to the file. Each process read access the
whole file and then exit. The process exit will do unmap_vmas() and cause
a lot of activate_page() call. In such workload, we saw about 58% total
time reduction with below patch. Other workloads with a lot of
activate_page also benefits a lot too.
Andrew Morton suggested activate_page() and putback_lru_pages() should
follow the same path to active pages, but this is hard to implement (see
commit
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14 years ago |
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Minchan Kim
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821ed6bbed |
mm: filter unevictable page out in deactivate_page()
It's pointless that deactive_page's operates on unevictable pages. This patch removes unnecessary overhead which might be a bit problem in case that there are many unevictable page in system(ex, mprotect workload) [akpm@linux-foundation.org: tidy up comment] Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: Rik van Riel<riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
14 years ago |
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Minchan Kim
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bad49d9c89 |
mm: check PageUnevictable in lru_deactivate_fn()
The lru_deactivate_fn should not move page which in on unevictable lru into inactive list. Otherwise, we can meet BUG when we use isolate_lru_pages as __isolate_lru_page could return -EINVAL. Reported-by: Ying Han <yinghan@google.com> Tested-by: Ying Han <yinghan@google.com> Signed-off-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Rik van Riel<riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
14 years ago |
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Shaohua Li
|
3dd7ae8ec0 |
mm: simplify code of swap.c
Clean up code and remove duplicate code. Next patch will use pagevec_lru_move_fn introduced here too. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Hiroyuki Kamezawa <kamezawa.hiroyuki@gmail.com> Cc: Andi Kleen <andi@firstfloor.org> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
14 years ago |
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Minchan Kim
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278df9f451 |
mm: reclaim invalidated page ASAP
invalidate_mapping_pages is very big hint to reclaimer. It means user
doesn't want to use the page any more. So in order to prevent working set
page eviction, this patch move the page into tail of inactive list by
PG_reclaim.
Please, remember that pages in inactive list are working set as well as
active list. If we don't move pages into inactive list's tail, pages near
by tail of inactive list can be evicted although we have a big clue about
useless pages. It's totally bad.
Now PG_readahead/PG_reclaim is shared.
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14 years ago |
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Minchan Kim
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3f58a82943 |
memcg: move memcg reclaimable page into tail of inactive list
The rotate_reclaimable_page function moves just written out pages, which the VM wanted to reclaim, to the end of the inactive list. That way the VM will find those pages first next time it needs to free memory. This patch applies the rule in memcg. It can help to prevent unnecessary working page eviction of memcg. Signed-off-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
14 years ago |
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Minchan Kim
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315601809d |
mm: deactivate invalidated pages
Recently, there are reported problem about thrashing. (http://marc.info/?l=rsync&m=128885034930933&w=2) It happens by backup workloads(ex, nightly rsync). That's because the workload makes just use-once pages and touches pages twice. It promotes the page into active list so that it results in working set page eviction. Some app developer want to support POSIX_FADV_NOREUSE. But other OSes don't support it, either. (http://marc.info/?l=linux-mm&m=128928979512086&w=2) By other approach, app developers use POSIX_FADV_DONTNEED. But it has a problem. If kernel meets page is writing during invalidate_mapping_pages, it can't work. It makes for application programmer to use it since they always have to sync data before calling fadivse(..POSIX_FADV_DONTNEED) to make sure the pages could be discardable. At last, they can't use deferred write of kernel so that they could see performance loss. (http://insights.oetiker.ch/linux/fadvise.html) In fact, invalidation is very big hint to reclaimer. It means we don't use the page any more. So let's move the writing page into inactive list's head if we can't truncate it right now. Why I move page to head of lru on this patch, Dirty/Writeback page would be flushed sooner or later. It can prevent writeout of pageout which is less effective than flusher's writeout. Originally, I reused lru_demote of Peter with some change so added his Signed-off-by. Signed-off-by: Minchan Kim <minchan.kim@gmail.com> Reported-by: Ben Gamari <bgamari.foss@gmail.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
14 years ago |