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2011-05-26memcg: add the pagefault count into memcg statsYing Han
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 0 Performance 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 <yinghan@google.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-26memcg: add memory.numastat api for numa statisticsYing Han
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=<total pages> N0=<node 0 pages> N1=<node 1 pages> ... file=<total file pages> N0=<node 0 pages> N1=<node 1 pages> ... anon=<total anon pages> N0=<node 0 pages> N1=<node 1 pages> ... unevictable=<total anon pages> N0=<node 0 pages> N1=<node 1 pages> ... 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=2941 Signed-off-by: Ying Han <yinghan@google.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> 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>
2011-05-26memcg: rename mem_cgroup_zone_nr_pages() to mem_cgroup_zone_nr_lru_pages()Ying Han
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 <yinghan@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-26memcg: remove unused retry signal from reclaimJohannes Weiner
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 <hannes@cmpxchg.org> Acked-by: Rik van Riel<riel@redhat.com> Acked-by: Ying Han<yinghan@google.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-26memcg: reclaim memory from nodes in round-robin orderYing Han
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 are Node 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 <yinghan@google.com> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> 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>
2011-05-26memcg: remove pointless next_mz nullification in mem_cgroup_soft_limit_reclaim()Michal Hocko
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 <mhocko@suse.cz> Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-26memcg: count the soft_limit reclaim in global background reclaimYing Han
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 240000 This 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 <yinghan@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-26cgroups: add per-thread subsystem callbacksBen Blum
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 <bblum@andrew.cmu.edu> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Matt Helsley <matthltc@us.ibm.com> Reviewed-by: Paul Menage <menage@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25memsw: remove noswapaccount kernel parameterMichal Hocko
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" strings Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: Hiroyuki Kamezawa <kamezawa.hiroyuki@gmail.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-31Fix common misspellingsLucas De Marchi
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-23memcg: fix leak on wrong LRU with FUSEKAMEZAWA Hiroyuki
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 <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Balbir Singh <balbir@in.ibm.com> Reported-by: Daniel Poelzleithner <poelzi@poelzi.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23mm/memcontrol.c: suppress uninitialized-var warning with older gcc'sAndrew Morton
mm/memcontrol.c: In function 'mem_cgroup_force_empty': mm/memcontrol.c:2280: warning: 'flags' may be used uninitialized in this function It's a false positive. Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Greg Thelen <gthelen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23memcg: use native word page statistics countersJohannes Weiner
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 <hannes@cmpxchg.org> Signed-off-by: Greg Thelen <gthelen@google.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23memcg: break out event counters from other statsJohannes Weiner
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 <hannes@cmpxchg.org> Signed-off-by: Greg Thelen <gthelen@google.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23memcg: unify charge/uncharge quantities to units of pagesJohannes Weiner
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 <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23memcg: convert uncharge batching from bytes to page granularityJohannes Weiner
We never uncharge subpage quantities. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23memcg: convert per-cpu stock from bytes to page granularityJohannes Weiner
We never keep subpage quantities in the per-cpu stock. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23memcg: keep only one charge cancelling functionJohannes Weiner
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 <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23memcg: remove memcg->reclaim_param_lockJohannes Weiner
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 <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23memcg: charged pages always have valid per-memcg zone infoJohannes Weiner
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 <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23memcg: remove direct page_cgroup-to-page pointerJohannes Weiner
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 <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23memcg: condense page_cgroup-to-page lookup pointsJohannes Weiner
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 <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.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>
2011-03-23memcg: fold __mem_cgroup_move_account into callerJohannes Weiner
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 <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.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>
2011-03-23memcg: change page_cgroup_zoneinfo signatureJohannes Weiner
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 <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.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>
2011-03-23memcg: no uncharged pages reach page_cgroup_zoneinfoJohannes Weiner
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 <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.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>
2011-03-23memcg: add memcg sanity checks at allocating and freeing pagesDaisuke Nishimura
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 <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.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>
2011-03-23memcg: remove NULL check from lookup_page_cgroup() resultJohannes Weiner
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 <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.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>
2011-03-23memcg: remove impossible conditional when committingJohannes Weiner
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 <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.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>
2011-03-23memcg: remove unused page flag bitfield definesJohannes Weiner
These definitions have been unused since '4b3bde4 memcg: remove the overhead associated with the root cgroup'. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.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>
2011-03-23memcg: simplify the way memory limits are checkedJohannes Weiner
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 <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.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>
2011-03-23memcg: soft limit reclaim should end at limit not belowJohannes Weiner
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 <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.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>
2011-03-23memcg: fix ugly initialization of return value is in callerKAMEZAWA Hiroyuki
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 <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22pagewalk: only split huge pages when necessaryDave Hansen
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 a cat /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 <dave@linux.vnet.ibm.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: David Rientjes <rientjes@google.com> Reviewed-by: Eric B Munson <emunson@mgebm.net> Tested-by: Eric B Munson <emunson@mgebm.net> Cc: Michael J Wolf <mjwolf@us.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matt Mackall <mpm@selenic.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22memcg: move memcg reclaimable page into tail of inactive listMinchan Kim
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>
2011-03-22mm: add replace_page_cache_page() functionMiklos Szeredi
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 <mszeredi@suse.cz> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-02memcg: fix event counting breakage from recent THP updateKAMEZAWA Hiroyuki
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 <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@in.ibm.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>
2011-02-02memcg: never OOM when charging huge pagesJohannes Weiner
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 <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-02memcg: prevent endless loop when charging huge pages to near-limit groupJohannes Weiner
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 <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-02memcg: prevent endless loop when charging huge pagesJohannes Weiner
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 <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-02memsw: deprecate noswapaccount kernel parameter and schedule it for removalMichal Hocko
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 <mhocko@suse.cz> Requested-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-02memsw: handle swapaccount kernel parameter correctlyMichal Hocko
__setup based kernel command line parameters handlers which are handled in obsolete_checksetup are provided with the parameter value including = (more precisely everything right after the parameter name). This means that the current implementation of swapaccount[=1|0] doesn't work at all because if there is a value for the parameter then we are testing for "0" resp. "1" but we are getting "=0" resp. "=1" and if there is no parameter value we are getting an empty string rather than NULL. The original noswapccount parameter, which doesn't care about the value, works correctly. Signed-off-by: Michal Hocko <mhocko@suse.cz> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-26memcg: fix race at move_parent around compound_order()KAMEZAWA Hiroyuki
A fix up mem_cgroup_move_parent() which use compound_order() in asynchronous manner. This compound_order() may return unknown value because we don't take lock. Use PageTransHuge() and HPAGE_SIZE instead of it. Also clean up for mem_cgroup_move_parent(). - remove unnecessary initialization of local variable. - rename charge_size -> page_size - remove unnecessary (wrong) comment. - added a comment about THP. Note: Current design take compound_page_lock() in caller of move_account(). This should be revisited when we implement direct move_task of hugepage without splitting. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-26memcg: bugfix check mem_cgroup_disabled() at split fixupKAMEZAWA Hiroyuki
mem_cgroup_disabled() should be checked at splitting. If disabled, no heavy work is necesary. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Reviewed-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-26memcg: fix account leak at failure of memsw accontingKAMEZAWA Hiroyuki
Commit 4b53433468 ("memcg: clean up try_charge main loop") removes a cancel of charge at case: memory charge-> success. mem+swap charge-> failure. This leaks usage of memory. Fix it. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@in.ibm.com> Cc: <stable@kernel.org> [2.6.36+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-26mm/memcontrol.c: fix uninitialized variable use in mem_cgroup_move_parent()Jesper Juhl
In mm/memcontrol.c::mem_cgroup_move_parent() there's a path that jumps to the 'put_back' label ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false, charge); if (ret || !parent) goto put_back; where we'll if (charge > PAGE_SIZE) compound_unlock_irqrestore(page, flags); but, we have not assigned anything to 'flags' at this point, nor have we called 'compound_lock_irqsave()' (which is what sets 'flags'). The 'put_back' label should be moved below the call to compound_unlock_irqrestore() as per this patch. Signed-off-by: Jesper Juhl <jj@chaosbits.net> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Pavel Emelianov <xemul@openvz.org> 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>
2011-01-20memcg: correctly order reading PCG_USED and pc->mem_cgroupJohannes Weiner
The placement of the read-side barrier is confused: the writer first sets pc->mem_cgroup, then PCG_USED. The read-side barrier has to be between testing PCG_USED and reading pc->mem_cgroup. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-20memcg: fix rmdir, force_empty with THPKAMEZAWA Hiroyuki
Now, when THP is enabled, memcg's rmdir() function is broken because move_account() for THP page is not supported. This will cause account leak or -EBUSY issue at rmdir(). This patch fixes the issue by supporting move_account() THP pages. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.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>
2011-01-20memcg: fix LRU accounting with THPKAMEZAWA Hiroyuki
memory cgroup's LRU stat should take care of size of pages because Transparent Hugepage inserts hugepage into LRU. If this value is the number wrong, memory reclaim will not work well. Note: only head page of THP's huge page is linked into LRU. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.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>
2011-01-20memcg: fix USED bit handling at uncharge in THPKAMEZAWA Hiroyuki
Now, under THP: at charge: - PageCgroupUsed bit is set to all page_cgroup on a hugepage. ....set to 512 pages. at uncharge - PageCgroupUsed bit is unset on the head page. So, some pages will remain with "Used" bit. This patch fixes that Used bit is set only to the head page. Used bits for tail pages will be set at splitting if necessary. This patch adds this lock order: compound_lock() -> page_cgroup_move_lock(). [akpm@linux-foundation.org: fix warning] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.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>
2011-01-20memcg: modify accounting function for supporting THP betterKAMEZAWA Hiroyuki
mem_cgroup_charge_statisics() was designed for charging a page but now, we have transparent hugepage. To fix problems (in following patch) it's required to change the function to get the number of pages as its arguments. The new function gets following as argument. - type of page rather than 'pc' - size of page which is accounted. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.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>