27 May, 2011
8 commits
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Two new stats in per-memcg memory.stat which tracks the number of page
faults and number of major page faults."pgfault"
"pgmajfault"They are different from "pgpgin"/"pgpgout" stat which count number of
pages charged/discharged to the cgroup and have no meaning of reading/
writing page to disk.It is valuable to track the two stats for both measuring application's
performance as well as the efficiency of the kernel page reclaim path.
Counting pagefaults per process is useful, but we also need the aggregated
value since processes are monitored and controlled in cgroup basis in
memcg.Functional test: check the total number of pgfault/pgmajfault of all
memcgs and compare with global vmstat value:$ cat /proc/vmstat | grep fault
pgfault 1070751
pgmajfault 553$ cat /dev/cgroup/memory.stat | grep fault
pgfault 1071138
pgmajfault 553
total_pgfault 1071142
total_pgmajfault 553$ cat /dev/cgroup/A/memory.stat | grep fault
pgfault 199
pgmajfault 0
total_pgfault 199
total_pgmajfault 0Performance test: run page fault test(pft) wit 16 thread on faulting in
15G anon pages in 16G container. There is no regression noticed on the
"flt/cpu/s"Sample output from pft:
TAG pft:anon-sys-default:
Gb Thr CLine User System Wall flt/cpu/s fault/wsec
15 16 1 0.67s 233.41s 14.76s 16798.546 266356.260+-------------------------------------------------------------------------+
N Min Max Median Avg Stddev
x 10 16682.962 17344.027 16913.524 16928.812 166.5362
+ 10 16695.568 16923.896 16820.604 16824.652 84.816568
No difference proven at 95.0% confidence[akpm@linux-foundation.org: fix build]
[hughd@google.com: shmem fix]
Signed-off-by: Ying Han
Acked-by: KAMEZAWA Hiroyuki
Cc: KOSAKI Motohiro
Reviewed-by: Minchan Kim
Cc: Daisuke Nishimura
Acked-by: Balbir Singh
Signed-off-by: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The new API exports numa_maps per-memcg basis. This is a piece of useful
information where it exports per-memcg page distribution across real numa
nodes.One of the usecases is evaluating application performance by combining
this information w/ the cpu allocation to the application.The output of the memory.numastat tries to follow w/ simiar format of
numa_maps like:total= N0= N1= ...
file= N0= N1= ...
anon= N0= N1= ...
unevictable= N0= N1= ...And we have per-node:
total = file + anon + unevictable
$ cat /dev/cgroup/memory/memory.numa_stat
total=250020 N0=87620 N1=52367 N2=45298 N3=64735
file=225232 N0=83402 N1=46160 N2=40522 N3=55148
anon=21053 N0=3424 N1=6207 N2=4776 N3=6646
unevictable=3735 N0=794 N1=0 N2=0 N3=2941Signed-off-by: Ying Han
Cc: Balbir Singh
Cc: Daisuke Nishimura
Acked-by: KAMEZAWA Hiroyuki
Acked-by: Daisuke Nishimura
Cc: Minchan Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The caller of the function has been renamed to zone_nr_lru_pages(), and
this is just fixing up in the memcg code. The current name is easily to
be mis-read as zone's total number of pages.Signed-off-by: Ying Han
Acked-by: Johannes Weiner
Acked-by: KAMEZAWA Hiroyuki
Reviewed-by: Minchan Kim
Cc: Balbir Singh
Cc: Daisuke Nishimura
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
If the memcg reclaim code detects the target memcg below its limit it
exits and returns a guaranteed non-zero value so that the charge is
retried.Nowadays, the charge side checks the memcg limit itself and does not rely
on this non-zero return value trick.This patch removes it. The reclaim code will now always return the true
number of pages it reclaimed on its own.Signed-off-by: Johannes Weiner
Acked-by: Rik van Riel
Acked-by: Ying Han
Acked-by: KAMEZAWA Hiroyuki
Reviewed-by: Michal Hocko
Cc: Balbir Singh
Cc: KOSAKI Motohiro
Cc: Mel Gorman
Cc: Daisuke Nishimura
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Presently, memory cgroup's direct reclaim frees memory from the current
node. But this has some troubles. Usually when a set of threads works in
a cooperative way, they tend to operate on the same node. So if they hit
limits under memcg they will reclaim memory from themselves, damaging the
active working set.For example, assume 2 node system which has Node 0 and Node 1 and a memcg
which has 1G limit. After some work, file cache remains and the usages
areNode 0: 1M
Node 1: 998M.and run an application on Node 0, it will eat its foot before freeing
unnecessary file caches.This patch adds round-robin for NUMA and adds equal pressure to each node.
When using cpuset's spread memory feature, this will work very well.But yes, a better algorithm is needed.
[akpm@linux-foundation.org: comment editing]
[kamezawa.hiroyu@jp.fujitsu.com: fix time comparisons]
Signed-off-by: Ying Han
Signed-off-by: KAMEZAWA Hiroyuki
Cc: Balbir Singh
Cc: KOSAKI Motohiro
Cc: Daisuke Nishimura
Cc: Mel Gorman
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
next_mz is assigned to NULL if __mem_cgroup_largest_soft_limit_node
selects the same mz. This doesn't make much sense as we assign to the
variable right in the next loop.Compiler will probably optimize this out but it is little bit confusing
for the code reading.Signed-off-by: Michal Hocko
Acked-by: Daisuke Nishimura
Cc: Balbir Singh
Cc: KAMEZAWA Hiroyuki
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The global kswapd scans per-zone LRU and reclaims pages regardless of the
cgroup. It breaks memory isolation since one cgroup can end up reclaiming
pages from another cgroup. Instead we should rely on memcg-aware target
reclaim including per-memcg kswapd and soft_limit hierarchical reclaim under
memory pressure.In the global background reclaim, we do soft reclaim before scanning the
per-zone LRU. However, the return value is ignored. This patch is the first
step to skip shrink_zone() if soft_limit reclaim does enough work.This is part of the effort which tries to reduce reclaiming pages in global
LRU in memcg. The per-memcg background reclaim patchset further enhances the
per-cgroup targetting reclaim, which I should have V4 posted shortly.Try running multiple memory intensive workloads within seperate memcgs. Watch
the counters of soft_steal in memory.stat.$ cat /dev/cgroup/A/memory.stat | grep 'soft'
soft_steal 240000
soft_scan 240000
total_soft_steal 240000
total_soft_scan 240000This patch:
In the global background reclaim, we do soft reclaim before scanning the
per-zone LRU. However, the return value is ignored.We would like to skip shrink_zone() if soft_limit reclaim does enough
work. Also, we need to make the memory pressure balanced across per-memcg
zones, like the logic vm-core. This patch is the first step where we
start with counting the nr_scanned and nr_reclaimed from soft_limit
reclaim into the global scan_control.Signed-off-by: Ying Han
Cc: KOSAKI Motohiro
Cc: Minchan Kim
Cc: Rik van Riel
Cc: Mel Gorman
Cc: KAMEZAWA Hiroyuki
Cc: Balbir Singh
Acked-by: Daisuke Nishimura
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add cgroup subsystem callbacks for per-thread attachment in atomic contexts
Add can_attach_task(), pre_attach(), and attach_task() as new callbacks
for cgroups's subsystem interface. Unlike can_attach and attach, these
are for per-thread operations, to be called potentially many times when
attaching an entire threadgroup.Also, the old "bool threadgroup" interface is removed, as replaced by
this. All subsystems are modified for the new interface - of note is
cpuset, which requires from/to nodemasks for attach to be globally scoped
(though per-cpuset would work too) to persist from its pre_attach to
attach_task and attach.This is a pre-patch for cgroup-procs-writable.patch.
Signed-off-by: Ben Blum
Cc: "Eric W. Biederman"
Cc: Li Zefan
Cc: Matt Helsley
Reviewed-by: Paul Menage
Cc: Oleg Nesterov
Cc: David Rientjes
Cc: Miao Xie
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
25 May, 2011
1 commit
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The noswapaccount parameter has been deprecated since 2.6.38 without any
complaints from users so we can remove it. swapaccount=0|1 can be used
instead.As we are removing the parameter we can also clean up swapaccount because
it doesn't have to accept an empty string anymore (to match noswapaccount)
and so we can push = into __setup macro rather than checking "=1" resp.
"=0" stringsSigned-off-by: Michal Hocko
Cc: Hiroyuki Kamezawa
Cc: Daisuke Nishimura
Cc: Balbir Singh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
31 Mar, 2011
1 commit
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Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: Lucas De Marchi
24 Mar, 2011
22 commits
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fs/fuse/dev.c::fuse_try_move_page() does
(1) remove a page by ->steal()
(2) re-add the page to page cache
(3) link the page to LRU if it was not on LRU at (1)This implies the page is _on_ LRU when it's added to radix-tree. So, the
page is added to memory cgroup while it's on LRU. because LRU is lazy and
no one flushs it.This is the same behavior as SwapCache and needs special care as
- remove page from LRU before overwrite pc->mem_cgroup.
- add page to LRU after overwrite pc->mem_cgroup.And we need to taking care of pagevec.
If PageLRU(page) is set before we add PCG_USED bit, the page will not be
added to memcg's LRU (in short period). So, regardlress of PageLRU(page)
value before commit_charge(), we need to check PageLRU(page) after
commit_charge().Addresses https://bugzilla.kernel.org/show_bug.cgi?id=30432
Signed-off-by: KAMEZAWA Hiroyuki
Reviewed-by: Johannes Weiner
Acked-by: Daisuke Nishimura
Cc: Miklos Szeredi
Cc: Balbir Singh
Reported-by: Daniel Poelzleithner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
mm/memcontrol.c: In function 'mem_cgroup_force_empty':
mm/memcontrol.c:2280: warning: 'flags' may be used uninitialized in this functionIt's a false positive.
Cc: Balbir Singh
Cc: Daisuke Nishimura
Cc: Greg Thelen
Cc: Johannes Weiner
Cc: KAMEZAWA Hiroyuki
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The statistic counters are in units of pages, there is no reason to make
them 64-bit wide on 32-bit machines.Make them native words. Since they are signed, this leaves 31 bit on
32-bit machines, which can represent roughly 8TB assuming a page size of
4k.[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Johannes Weiner
Signed-off-by: Greg Thelen
Acked-by: KAMEZAWA Hiroyuki
Acked-by: Balbir Singh
Cc: Daisuke Nishimura
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
For increasing and decreasing per-cpu cgroup usage counters it makes sense
to use signed types, as single per-cpu values might go negative during
updates. But this is not the case for only-ever-increasing event
counters.All the counters have been signed 64-bit so far, which was enough to count
events even with the sign bit wasted.This patch:
- divides s64 counters into signed usage counters and unsigned
monotonically increasing event counters.
- converts unsigned event counters into 'unsigned long' rather than
'u64'. This matches the type used by the /proc/vmstat event counters.The next patch narrows the signed usage counters type (on 32-bit CPUs,
that is).Signed-off-by: Johannes Weiner
Signed-off-by: Greg Thelen
Acked-by: KAMEZAWA Hiroyuki
Acked-by: Balbir Singh
Cc: Daisuke Nishimura
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
There is no clear pattern when we pass a page count and when we pass a
byte count that is a multiple of PAGE_SIZE.We never charge or uncharge subpage quantities, so convert it all to page
counts.Signed-off-by: Johannes Weiner
Acked-by: KAMEZAWA Hiroyuki
Cc: Daisuke Nishimura
Cc: Balbir Singh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
We never uncharge subpage quantities.
Signed-off-by: Johannes Weiner
Acked-by: KAMEZAWA Hiroyuki
Cc: Daisuke Nishimura
Cc: Balbir Singh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
We never keep subpage quantities in the per-cpu stock.
Signed-off-by: Johannes Weiner
Acked-by: KAMEZAWA Hiroyuki
Cc: Daisuke Nishimura
Cc: Balbir Singh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
We have two charge cancelling functions: one takes a page count, the other
a page size. The second one just divides the parameter by PAGE_SIZE and
then calls the first one. This is trivial, no need for an extra function.Signed-off-by: Johannes Weiner
Acked-by: KAMEZAWA Hiroyuki
Cc: Daisuke Nishimura
Cc: Balbir Singh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The reclaim_param_lock is only taken around single reads and writes to
integer variables and is thus superfluous. Drop it.Signed-off-by: Johannes Weiner
Acked-by: KAMEZAWA Hiroyuki
Cc: Daisuke Nishimura
Cc: Balbir Singh
Reviewed-by: Minchan Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
page_cgroup_zoneinfo() will never return NULL for a charged page, remove
the check for it in mem_cgroup_get_reclaim_stat_from_page().Signed-off-by: Johannes Weiner
Acked-by: KAMEZAWA Hiroyuki
Cc: Daisuke Nishimura
Cc: Balbir Singh
Reviewed-by: Minchan Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
In struct page_cgroup, we have a full word for flags but only a few are
reserved. Use the remaining upper bits to encode, depending on
configuration, the node or the section, to enable page_cgroup-to-page
lookups without a direct pointer.This saves a full word for every page in a system with memory cgroups
enabled.Signed-off-by: Johannes Weiner
Acked-by: KAMEZAWA Hiroyuki
Cc: Daisuke Nishimura
Cc: Balbir Singh
Cc: Minchan Kim
Cc: Randy Dunlap
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The per-cgroup LRU lists string up 'struct page_cgroup's. To get from
those structures to the page they represent, a lookup is required.
Currently, the lookup is done through a direct pointer in struct
page_cgroup, so a lot of functions down the callchain do this lookup by
themselves instead of receiving the page pointer from their callers.The next patch removes this pointer, however, and the lookup is no longer
that straight-forward. In preparation for that, this patch only leaves
the non-optional lookups when coming directly from the LRU list and passes
the page down the stack.Signed-off-by: Johannes Weiner
Acked-by: KAMEZAWA Hiroyuki
Cc: Daisuke Nishimura
Cc: Balbir Singh
Cc: Minchan Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
It is one logical function, no need to have it split up.
Also, get rid of some checks from the inner function that ensured the
sanity of the outer function.Signed-off-by: Johannes Weiner
Acked-by: KAMEZAWA Hiroyuki
Acked-by: Daisuke Nishimura
Cc: Balbir Singh
Cc: Minchan Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Instead of passing a whole struct page_cgroup to this function, let it
take only what it really needs from it: the struct mem_cgroup and the
page.This has the advantage that reading pc->mem_cgroup is now done at the same
place where the ordering rules for this pointer are enforced and
explained.It is also in preparation for removing the pc->page backpointer.
Signed-off-by: Johannes Weiner
Acked-by: KAMEZAWA Hiroyuki
Cc: Daisuke Nishimura
Cc: Balbir Singh
Cc: Minchan Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch series removes the direct page pointer from struct page_cgroup,
which saves 20% of per-page memcg memory overhead (Fedora and Ubuntu
enable memcg per default, openSUSE apparently too).The node id or section number is encoded in the remaining free bits of
pc->flags which allows calculating the corresponding page without the
extra pointer.I ran, what I think is, a worst-case microbenchmark that just cats a large
sparse file to /dev/null, because it means that walking the LRU list on
behalf of per-cgroup reclaim and looking up pages from page_cgroups is
happening constantly and at a high rate. But it made no measurable
difference. A profile reported a 0.11% share of the new
lookup_cgroup_page() function in this benchmark.This patch:
All callsites check PCG_USED before passing pc->mem_cgroup, so the latter
is never NULL.Signed-off-by: Johannes Weiner
Acked-by: KAMEZAWA Hiroyuki
Cc: Daisuke Nishimura
Acked-by: Balbir Singh
Cc: Minchan Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add checks at allocating or freeing a page whether the page is used (iow,
charged) from the view point of memcg.This check may be useful in debugging a problem and we did similar checks
before the commit 52d4b9ac(memcg: allocate all page_cgroup at boot).This patch adds some overheads at allocating or freeing memory, so it's
enabled only when CONFIG_DEBUG_VM is enabled.Signed-off-by: Daisuke Nishimura
Signed-off-by: Johannes Weiner
Acked-by: KAMEZAWA Hiroyuki
Cc: Balbir Singh
Cc: Minchan Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The page_cgroup array is set up before even fork is initialized. I
seriously doubt that this code executes before the array is alloc'd.Signed-off-by: Johannes Weiner
Acked-by: KAMEZAWA Hiroyuki
Cc: Daisuke Nishimura
Cc: Balbir Singh
Cc: Minchan Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
No callsite ever passes a NULL pointer for a struct mem_cgroup * to the
committing function. There is no need to check for it.Signed-off-by: Johannes Weiner
Acked-by: KAMEZAWA Hiroyuki
Cc: Daisuke Nishimura
Cc: Balbir Singh
Cc: Minchan Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
These definitions have been unused since '4b3bde4 memcg: remove the
overhead associated with the root cgroup'.Signed-off-by: Johannes Weiner
Acked-by: KAMEZAWA Hiroyuki
Cc: Daisuke Nishimura
Cc: Balbir Singh
Cc: Minchan Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Since transparent huge pages, checking whether memory cgroups are below
their limits is no longer enough, but the actual amount of chargeable
space is important.To not have more than one limit-checking interface, replace
memory_cgroup_check_under_limit() and memory_cgroup_check_margin() with a
single memory_cgroup_margin() that returns the chargeable space and leaves
the comparison to the callsite.Soft limits are now checked the other way round, by using the already
existing function that returns the amount by which soft limits are
exceeded: res_counter_soft_limit_excess().Also remove all the corresponding functions on the res_counter side that
are now no longer used.Signed-off-by: Johannes Weiner
Acked-by: KAMEZAWA Hiroyuki
Cc: Daisuke Nishimura
Acked-by: Balbir Singh
Cc: Minchan Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Soft limit reclaim continues until the usage is below the current soft
limit, but the documented semantics are actually that soft limit reclaim
will push usage back until the soft limits are met again.Signed-off-by: Johannes Weiner
Acked-by: KAMEZAWA Hiroyuki
Cc: Daisuke Nishimura
Acked-by: Balbir Singh
Cc: Minchan Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Remove initialization of vaiable in caller of memory cgroup function.
Actually, it's return value of memcg function but it's initialized in
caller.Some memory cgroup uses following style to bring the result of start
function to the end function for avoiding races.mem_cgroup_start_A(&(*ptr))
/* Something very complicated can happen here. */
mem_cgroup_end_A(*ptr)In some calls, *ptr should be initialized to NULL be caller. But it's
ugly. This patch fixes that *ptr is initialized by _start function.Signed-off-by: KAMEZAWA Hiroyuki
Acked-by: Johannes Weiner
Acked-by: Daisuke Nishimura
Cc: Balbir Singh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
23 Mar, 2011
3 commits
-
Right now, if a mm_walk has either ->pte_entry or ->pmd_entry set, it will
unconditionally split any transparent huge pages it runs in to. In
practice, that means that anyone doing acat /proc/$pid/smaps
will unconditionally break down every huge page in the process and depend
on khugepaged to re-collapse it later. This is fairly suboptimal.This patch changes that behavior. It teaches each ->pmd_entry handler
(there are five) that they must break down the THPs themselves. Also, the
_generic_ code will never break down a THP unless a ->pte_entry handler is
actually set.This means that the ->pmd_entry handlers can now choose to deal with THPs
without breaking them down.[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Dave Hansen
Acked-by: Mel Gorman
Acked-by: David Rientjes
Reviewed-by: Eric B Munson
Tested-by: Eric B Munson
Cc: Michael J Wolf
Cc: Andrea Arcangeli
Cc: Johannes Weiner
Cc: Matt Mackall
Cc: Jeremy Fitzhardinge
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Acked-by: Balbir Singh
Acked-by: KAMEZAWA Hiroyuki
Reviewed-by: Rik van Riel
Cc: KOSAKI Motohiro
Acked-by: Johannes Weiner
Cc: Andrea Arcangeli
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This function basically does:
remove_from_page_cache(old);
page_cache_release(old);
add_to_page_cache_locked(new);Except it does this atomically, so there's no possibility for the "add" to
fail because of a race.If memory cgroups are enabled, then the memory cgroup charge is also moved
from the old page to the new.This function is currently used by fuse to move pages into the page cache
on read, instead of copying the page contents.[minchan.kim@gmail.com: add freepage() hook to replace_page_cache_page()]
Signed-off-by: Miklos Szeredi
Acked-by: Rik van Riel
Acked-by: KAMEZAWA Hiroyuki
Cc: Mel Gorman
Signed-off-by: Minchan Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
03 Feb, 2011
5 commits
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Changes in e401f1761 ("memcg: modify accounting function for supporting
THP better") adds nr_pages to support multiple page size in
memory_cgroup_charge_statistics.But counting the number of event nees abs(nr_pages) for increasing
counters. This patch fixes event counting.Signed-off-by: KAMEZAWA Hiroyuki
Reviewed-by: Johannes Weiner
Cc: Daisuke Nishimura
Cc: Balbir Singh
Cc: Minchan Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Huge page coverage should obviously have less priority than the continued
execution of a process.Never kill a process when charging it a huge page fails. Instead, give up
after the first failed reclaim attempt and fall back to regular pages.Signed-off-by: Johannes Weiner
Acked-by: KAMEZAWA Hiroyuki
Reviewed-by: Minchan Kim
Cc: Balbir Singh
Cc: Daisuke Nishimura
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
If reclaim after a failed charging was unsuccessful, the limits are
checked again, just in case they settled by means of other tasks.This is all fine as long as every charge is of size PAGE_SIZE, because in
that case, being below the limit means having at least PAGE_SIZE bytes
available.But with transparent huge pages, we may end up in an endless loop where
charging and reclaim fail, but we keep going because the limits are not
yet exceeded, although not allowing for a huge page.Fix this up by explicitely checking for enough room, not just whether we
are within limits.Signed-off-by: Johannes Weiner
Acked-by: KAMEZAWA Hiroyuki
Reviewed-by: Minchan Kim
Cc: Balbir Singh
Cc: Daisuke Nishimura
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The charging code can encounter a charge size that is bigger than a
regular page in two situations: one is a batched charge to fill the
per-cpu stocks, the other is a huge page charge.This code is distributed over two functions, however, and only the outer
one is aware of huge pages. In case the charging fails, the inner
function will tell the outer function to retry if the charge size is
bigger than regular pages--assuming batched charging is the only case.
And the outer function will retry forever charging a huge page.This patch makes sure the inner function can distinguish between batch
charging and a single huge page charge. It will only signal another
attempt if batch charging failed, and go into regular reclaim when it is
called on behalf of a huge page.Signed-off-by: Johannes Weiner
Acked-by: KAMEZAWA Hiroyuki
Reviewed-by: Minchan Kim
Cc: Balbir Singh
Cc: Daisuke Nishimura
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
noswapaccount couldn't be used to control memsw for both on/off cases so
we have added swapaccount[=0|1] parameter. This way we can turn the
feature in two ways noswapaccount resp. swapaccount=0. We have kept the
original noswapaccount but I think we should remove it after some time as
it just makes more command line parameters without any advantages and also
the code to handle parameters is uglier if we want both parameters.Signed-off-by: Michal Hocko
Requested-by: KAMEZAWA Hiroyuki
Acked-by: KAMEZAWA Hiroyuki
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds