summaryrefslogtreecommitdiff
path: root/mm/page_cgroup.c
AgeCommit message (Collapse)AuthorFilesLines
2012-12-13memcontrol: use N_MEMORY instead N_HIGH_MEMORYLai Jiangshan1-1/+1
N_HIGH_MEMORY stands for the nodes that has normal or high memory. N_MEMORY stands for the nodes that has any memory. The code here need to handle with the nodes which have memory, we should use N_MEMORY instead. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Cc: Christoph Lameter <cl@linux.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: Lin Feng <linfeng@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-12memory-hotplug: auto offline page_cgroup when onlining memory block failedWen Congyang1-0/+3
When a memory block is onlined, we will try allocate memory on that node to store page_cgroup. If onlining the memory block failed, we don't offline the page cgroup, and we have no chance to offline this page cgroup unless the memory block is onlined successfully again. It will cause that we can't hot-remove the memory device on that node, because some memory is used to store page cgroup. If onlining the memory block is failed, there is no need to stort page cgroup for this memory. So auto offline page_cgroup when onlining memory block failed. Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Jiang Liu <liuj97@gmail.com> Cc: Len Brown <len.brown@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Christoph Lameter <cl@linux.com> Cc: Minchan Kim <minchan.kim@gmail.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Dave Hansen <dave@linux.vnet.ibm.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>
2012-08-01memcg: rename config variablesAndrew Morton1-1/+1
Sanity: CONFIG_CGROUP_MEM_RES_CTLR -> CONFIG_MEMCG CONFIG_CGROUP_MEM_RES_CTLR_SWAP -> CONFIG_MEMCG_SWAP CONFIG_CGROUP_MEM_RES_CTLR_SWAP_ENABLED -> CONFIG_MEMCG_SWAP_ENABLED CONFIG_CGROUP_MEM_RES_CTLR_KMEM -> CONFIG_MEMCG_KMEM [mhocko@suse.cz: fix missed bits] Cc: Glauber Costa <glommer@parallels.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: David Rientjes <rientjes@google.com> 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>
2012-06-21mm: fix kernel-doc warningsWanpeng Li1-2/+2
Fix kernel-doc warnings such as Warning(../mm/page_cgroup.c:432): No description found for parameter 'id' Warning(../mm/page_cgroup.c:432): Excess function parameter 'mem' description in 'swap_cgroup_record' Signed-off-by: Wanpeng Li <liwp@linux.vnet.ibm.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>
2012-03-06page_cgroup: fix horrid swap accounting regressionHugh Dickins1-1/+3
Why is memcg's swap accounting so broken? Insane counts, wrong ownership, unfreeable structures, which later get freed and then accessed after free. Turns out to be a tiny a little 3.3-rc1 regression in 9fb4b7cc0724 "page_cgroup: add helper function to get swap_cgroup": the helper function (actually named lookup_swap_cgroup()) returns an address using void* arithmetic, but the structure in question is a short. Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: Bob Liu <lliubbo@gmail.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-13page_cgroup: drop multi CONFIG_MEMORY_HOTPLUGBob Liu1-16/+14
No need for two CONFIG_MEMORY_HOTPLUG blocks. Signed-off-by: Bob Liu <lliubbo@gmail.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> 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>
2012-01-13page_cgroup: add helper function to get swap_cgroupBob Liu1-36/+20
There are multiple places which need to get the swap_cgroup address, so add a helper function: static struct swap_cgroup *swap_cgroup_getsc(swp_entry_t ent, struct swap_cgroup_ctrl **ctrl); to simplify the code. Signed-off-by: Bob Liu <lliubbo@gmail.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-13mm: page_cgroup: check page_cgroup arrays in lookup_page_cgroup() only when ↵Johannes Weiner1-2/+16
necessary lookup_page_cgroup() is usually used only against pages that are used in userspace. The exception is the CONFIG_DEBUG_VM-only memcg check from the page allocator: it can run on pages without page_cgroup descriptors allocated when the pages are fed into the page allocator for the first time during boot or memory hotplug. Include the array check only when CONFIG_DEBUG_VM is set and save the unnecessary check in production kernels. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Balbir Singh <bsingharora@gmail.com> Cc: David Rientjes <rientjes@google.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>
2012-01-13mm: memcg: remove unused node/section info from pc->flagsJohannes Weiner1-52/+7
To find the page corresponding to a certain page_cgroup, the pc->flags encoded the node or section ID with the base array to compare the pc pointer to. Now that the per-memory cgroup LRU lists link page descriptors directly, there is no longer any code that knows the struct page_cgroup of a PFN but not the struct page. [hughd@google.com: remove unused node/section info from pc->flags fix] 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: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: "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> 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>
2012-01-13mm: make per-memcg LRU lists exclusiveJohannes Weiner1-1/+0
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>
2011-11-03mm/page_cgroup.c: quiet sparse noiseH Hartley Sweeten1-1/+1
warning: symbol 'swap_cgroup_ctrl' was not declared. Should it be static? Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Cc: Paul Menage <paul@paulmenage.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Balbir Singh <bsingharora@gmail.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> 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>
2011-11-03cgroup/kmemleak: Annotate alloc_page() for cgroup allocationsSteven Rostedt1-2/+5
When the cgroup base was allocated with kmalloc, it was necessary to annotate the variable with kmemleak_not_leak(). But because it has recently been changed to be allocated with alloc_page() (which skips kmemleak checks) causes a warning on boot up. I was triggering this output: allocated 8388608 bytes of page_cgroup please try 'cgroup_disable=memory' option if you don't want memory cgroups kmemleak: Trying to color unknown object at 0xf5840000 as Grey Pid: 0, comm: swapper Not tainted 3.0.0-test #12 Call Trace: [<c17e34e6>] ? printk+0x1d/0x1f^M [<c10e2941>] paint_ptr+0x4f/0x78 [<c178ab57>] kmemleak_not_leak+0x58/0x7d [<c108ae9f>] ? __rcu_read_unlock+0x9/0x7d [<c1cdb462>] kmemleak_init+0x19d/0x1e9 [<c1cbf771>] start_kernel+0x346/0x3ec [<c1cbf1b4>] ? loglevel+0x18/0x18 [<c1cbf0aa>] i386_start_kernel+0xaa/0xb0 After a bit of debugging I tracked the object 0xf840000 (and others) down to the cgroup code. The change from allocating base with kmalloc to alloc_page() has the base not calling kmemleak_alloc() which adds the pointer to the object_tree_root, but kmemleak_not_leak() adds it to the crt_early_log[] table. On kmemleak_init(), the entry is found in the early_log[] but not the object_tree_root, and this error message is displayed. If alloc_page() fails then it defaults back to vmalloc() which still uses the kmemleak_alloc() which makes us still need the kmemleak_not_leak() call. The solution is to call the kmemleak_alloc() directly if the alloc_page() succeeds. Reviewed-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-09-15mm: Convert vmalloc/memset to vzallocJoe Perches1-2/+1
Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-07-26mm/page_cgroup.c: simplify code by using SECTION_ALIGN_UP() and ↵Daniel Kiper1-4/+4
SECTION_ALIGN_DOWN() macros Commit a539f3533b78e3 ("mm: add SECTION_ALIGN_UP() and SECTION_ALIGN_DOWN() macro") introduced the SECTION_ALIGN_UP() and SECTION_ALIGN_DOWN() macros. Use those macros to increase code readability. Signed-off-by: Daniel Kiper <dkiper@net-space.pl> Acked-by: David Rientjes <rientjes@google.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>
2011-07-26mm: remove the leftovers of noswapaccountWANG Cong1-1/+1
In commit a2c8990aed5ab ("memsw: remove noswapaccount kernel parameter"), Michal forgot to remove some left pieces of noswapaccount in the tree, this patch removes them all. Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com> Acked-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-06-16memcg: fix init_page_cgroup nid with sparsememKAMEZAWA Hiroyuki1-18/+53
Commit 21a3c9646873 ("memcg: allocate memory cgroup structures in local nodes") makes page_cgroup allocation as NUMA aware. But that caused a problem https://bugzilla.kernel.org/show_bug.cgi?id=36192. The problem was getting a NID from invalid struct pages, which was not initialized because it was out-of-node, out of [node_start_pfn, node_end_pfn) Now, with sparsemem, page_cgroup_init scans pfn from 0 to max_pfn. But this may scan a pfn which is not on any node and can access memmap which is not initialized. This makes page_cgroup_init() for SPARSEMEM node aware and remove a code to get nid from page->flags. (Then, we'll use valid NID always.) [akpm@linux-foundation.org: try to fix up comments] Signed-off-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>
2011-05-27memcg: move page-freeing code out of lockNamhyung Kim1-9/+13
Move page-freeing code out of swap_cgroup_mutex in the hope that it could reduce few of theoretical contentions between swapons and/or swapoffs. This is just a cleanup, no functional changes. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-27memcg: fix off-by-one when calculating swap cgroup map lengthNamhyung Kim1-1/+1
It allocated one more page than necessary if @max_pages was a multiple of SC_PER_PAGE. Signed-off-by: Namhyung Kim <namhyung@gmail.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> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-27memcg: mark init_section_page_cgroup() properlyNamhyung Kim1-2/+2
Commit ca371c0d7e23 ("memcg: fix page_cgroup fatal error in FLATMEM") removes call to alloc_bootmem() in the function so that it can be marked as __meminit to reduce memory usage when MEMORY_HOTPLUG=n. Also as the new helper function alloc_page_cgroup() is called only in the function, it should be marked too. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Michal Hocko <mhocko@suse.cz> 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>
2011-05-12memcg: allocate memory cgroup structures in local nodesAndi Kleen1-1/+1
Commit dde79e005a769 ("page_cgroup: reduce allocation overhead for page_cgroup array for CONFIG_SPARSEMEM") added a regression that the memory cgroup data structures all end up in node 0 because the first attempt at allocating them would not pass in a node hint. Since the initialization runs on CPU #0 it would all end up node 0. This is a problem on large memory systems, where node 0 would lose a lot of memory. Change the alloc_pages_exact() to alloc_pages_exact_nid(). This will still fall back to other nodes if not enough memory is available. [ RED-PEN: right now it would fall back first before trying vmalloc_node. Probably not the best strategy ... But I left it like that for now. ] Signed-off-by: Andi Kleen <ak@linux.intel.com> Reported-by: Doug Nelson Cc: David Rientjes <rientjes@google.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> 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>
2011-03-31Fix common misspellingsLucas De Marchi1-1/+1
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-24memcg: page_cgroup array is never stored on reserved pagesMichal Hocko1-5/+5
KAMEZAWA Hiroyuki noted that free_pages_cgroup doesn't have to check for PageReserved because we never store the array on reserved pages (neither alloc_pages_exact nor vmalloc use those pages). So we can replace the check by a BUG_ON. Signed-off-by: Michal Hocko <mhocko@suse.cz> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> 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>
2011-03-24page_cgroup: reduce allocation overhead for page_cgroup array for ↵Michal Hocko1-22/+36
CONFIG_SPARSEMEM Currently we are allocating a single page_cgroup array per memory section (stored in mem_section->base) when CONFIG_SPARSEMEM is selected. This is correct but memory inefficient solution because the allocated memory (unless we fall back to vmalloc) is not kmalloc friendly: - 32b - 16384 entries (20B per entry) fit into 327680B so the 524288B slab cache is used - 32b with PAE - 131072 entries with 2621440B fit into 4194304B - 64b - 32768 entries (40B per entry) fit into 2097152 cache This is ~37% wasted space per memory section and it sumps up for the whole memory. On a x86_64 machine it is something like 6MB per 1GB of RAM. We can reduce the internal fragmentation by using alloc_pages_exact which allocates PAGE_SIZE aligned blocks so we will get down to <4kB wasted memory per section which is much better. We still need a fallback to vmalloc because we have no guarantees that we will have a continuous memory of that size (order-10) later on during the hotplug events. [hannes@cmpxchg.org: do not define unused free_page_cgroup() without memory hotplug] Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-24memcg: remove direct page_cgroup-to-page pointerJohannes Weiner1-36/+55
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>
2011-03-23mm: notifier_from_errno() cleanupPrarit Bhargava1-6/+1
While looking at some other notifier callbacks I noticed this code could use a simple cleanup. notifier_from_errno() no longer needs the if (ret)/else conditional. That same conditional is now done in notifier_from_errno(). Signed-off-by: Prarit Bhargava <prarit@redhat.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-07-19kmemleak: Annotate false positive in init_section_page_cgroup()Catalin Marinas1-0/+7
The pointer to the page_cgroup table allocated in init_section_page_cgroup() is stored in section->page_cgroup as (base - pfn). Since this value does not point to the beginning or inside the allocated memory block, kmemleak reports a false positive. This was reported in bugzilla.kernel.org as #16297. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Adrien Dessemond <adrien.dessemond@gmail.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Andrew Morton <akpm@linux-foundation.org>
2010-03-18memcg: avoid use cmpxchg in swap cgroup maintainanceKAMEZAWA Hiroyuki1-4/+16
swap_cgroup uses 2bytes data and uses cmpxchg in a new operation. 2byte cmpxchg/xchg is not available on some archs. This patch replaces cmpxchg/xchg with operations under lock. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reported-by: Sachin Sant <sachinp@in.ibm.com> wrote: Acked-by: Balbir Singh <balbir@in.ibm.com> Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-13memcg: move charges of anonymous swapDaisuke Nishimura1-2/+32
This patch is another core part of this move-charge-at-task-migration feature. It enables moving charges of anonymous swaps. To move the charge of swap, we need to exchange swap_cgroup's record. In current implementation, swap_cgroup's record is protected by: - page lock: if the entry is on swap cache. - swap_lock: if the entry is not on swap cache. This works well in usual swap-in/out activity. But this behavior make the feature of moving swap charge check many conditions to exchange swap_cgroup's record safely. So I changed modification of swap_cgroup's recored(swap_cgroup_record()) to use xchg, and define a new function to cmpxchg swap_cgroup's record. This patch also enables moving charge of non pte_present but not uncharged swap caches, which can be exist on swap-out path, by getting the target pages via find_get_page() as do_mincore() does. [kosaki.motohiro@jp.fujitsu.com: fix ia64 build] [akpm@linux-foundation.org: fix typos] Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-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>
2009-09-22memory hotplug: alloc page from other node in memory onlineShaohua Li1-3/+9
To initialize hotadded node, some pages are allocated. At that time, the node hasn't memory, this makes the allocation always fail. In such case, let's allocate pages from other nodes. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Yakui Zhao <yakui.zhao@intel.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-19memcg: remove some redundant checksLi Zefan1-8/+0
We don't need to check do_swap_account in the case that the function which checks do_swap_account will never get called if do_swap_account == 0. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.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>
2009-06-19memcg: add file-based RSS accountingBalbir Singh1-0/+2
Add file RSS tracking per memory cgroup We currently don't track file RSS, the RSS we report is actually anon RSS. All the file mapped pages, come in through the page cache and get accounted there. This patch adds support for accounting file RSS pages. It should 1. Help improve the metrics reported by the memory resource controller 2. Will form the basis for a future shared memory accounting heuristic that has been proposed by Kamezawa. Unfortunately, we cannot rename the existing "rss" keyword used in memory.stat to "anon_rss". We however, add "mapped_file" data and hope to educate the end user through documentation. [hugh.dickins@tiscali.co.uk: fix mem_cgroup_update_mapped_file_stat oops] Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.cn> Cc: Paul Menage <menage@google.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-19cgroups: make messages more readableRandy Dunlap1-7/+7
Fix some cgroup messages to read better. Update MAINTAINERS to include mm/*cgroup* files. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-12memcg: fix page_cgroup fatal error in FLATMEMKAMEZAWA Hiroyuki1-19/+10
Now, SLAB is configured in very early stage and it can be used in init routine now. But replacing alloc_bootmem() in FLAT/DISCONTIGMEM's page_cgroup() initialization breaks the allocation, now. (Works well in SPARSEMEM case...it supports MEMORY_HOTPLUG and size of page_cgroup is in reasonable size (< 1 << MAX_ORDER.) This patch revive FLATMEM+memory cgroup by using alloc_bootmem. In future, We stop to support FLATMEM (if no users) or rewrite codes for flatmem completely.But this will adds more messy codes and overheads. Reported-by: Li Zefan <lizf@cn.fujitsu.com> Tested-by: Li Zefan <lizf@cn.fujitsu.com> Tested-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2009-06-11memcg: don't use bootmem allocator in setup codeYinghai Lu1-4/+8
The bootmem allocator is no longer available for page_cgroup_init() because we set up the kernel slab allocator much earlier now. Cc: Ingo Molnar <mingo@elte.hu> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2009-04-03memcg: remove redundant message at swaponKAMEZAWA Hiroyuki1-7/+0
It's pointed out that swap_cgroup's message at swapon() is nonsense. Because * It can be calculated very easily if all necessary information is written in Kconfig. * It's not necessary to annoying people at every swapon(). In other view, now, memory usage per swp_entry is reduced to 2bytes from 8bytes(64bit) and I think it's reasonably small. Reported-by: Hugh Dickins <hugh@veritas.com> Signed-off-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>
2009-04-03cgroups: use css id in swap cgroup for saving memory v5KAMEZAWA Hiroyuki1-18/+14
Try to use CSS ID for records in swap_cgroup. By this, on 64bit machine, size of swap_cgroup goes down to 2 bytes from 8bytes. This means, when 2GB of swap is equipped, (assume the page size is 4096bytes) From size of swap_cgroup = 2G/4k * 8 = 4Mbytes. To size of swap_cgroup = 2G/4k * 2 = 1Mbytes. Reduction is large. Of course, there are trade-offs. This CSS ID will add overhead to swap-in/swap-out/swap-free. But in general, - swap is a resource which the user tend to avoid use. - If swap is never used, swap_cgroup area is not used. - Reading traditional manuals, size of swap should be proportional to size of memory. Memory size of machine is increasing now. I think reducing size of swap_cgroup makes sense. Note: - ID->CSS lookup routine has no locks, it's under RCU-Read-Side. - memcg can be obsolete at rmdir() but not freed while refcnt from swap_cgroup is available. Changelog v4->v5: - reworked on to memcg-charge-swapcache-to-proper-memcg.patch Changlog ->v4: - fixed not configured case. - deleted unnecessary comments. - fixed NULL pointer bug. - fixed message in dmesg. [nishimura@mxp.nes.nec.co.jp: css_tryget can be called twice in !PageCgroupUsed case] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-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>
2009-02-12memcg: use __GFP_NOWARN in page cgroup allocationKAMEZAWA Hiroyuki1-1/+2
page_cgroup's page allocation at init/memory hotplug uses kmalloc() and vmalloc(). If kmalloc() failes, vmalloc() is used. This is because vmalloc() is very limited resource on 32bit systems. We want to use kmalloc() first. But in this kind of call, __GFP_NOWARN should be specified. Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08memcg: add mem_cgroup_disabled()Hirokazu Takahashi1-2/+2
We check mem_cgroup is disabled or not by checking mem_cgroup_subsys.disabled. I think it has more references than expected, now. replacing if (mem_cgroup_subsys.disabled) with if (mem_cgroup_disabled()) give us good look, I think. [kamezawa.hiroyu@jp.fujitsu.com: fix typo] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08memcg: synchronized LRUKAMEZAWA Hiroyuki1-0/+1
A big patch for changing memcg's LRU semantics. Now, - page_cgroup is linked to mem_cgroup's its own LRU (per zone). - LRU of page_cgroup is not synchronous with global LRU. - page and page_cgroup is one-to-one and statically allocated. - To find page_cgroup is on what LRU, you have to check pc->mem_cgroup as - lru = page_cgroup_zoneinfo(pc, nid_of_pc, zid_of_pc); - SwapCache is handled. And, when we handle LRU list of page_cgroup, we do following. pc = lookup_page_cgroup(page); lock_page_cgroup(pc); .....................(1) mz = page_cgroup_zoneinfo(pc); spin_lock(&mz->lru_lock); .....add to LRU spin_unlock(&mz->lru_lock); unlock_page_cgroup(pc); But (1) is spin_lock and we have to be afraid of dead-lock with zone->lru_lock. So, trylock() is used at (1), now. Without (1), we can't trust "mz" is correct. This is a trial to remove this dirty nesting of locks. This patch changes mz->lru_lock to be zone->lru_lock. Then, above sequence will be written as spin_lock(&zone->lru_lock); # in vmscan.c or swap.c via global LRU mem_cgroup_add/remove/etc_lru() { pc = lookup_page_cgroup(page); mz = page_cgroup_zoneinfo(pc); if (PageCgroupUsed(pc)) { ....add to LRU } spin_lock(&zone->lru_lock); # in vmscan.c or swap.c via global LRU This is much simpler. (*) We're safe even if we don't take lock_page_cgroup(pc). Because.. 1. When pc->mem_cgroup can be modified. - at charge. - at account_move(). 2. at charge the PCG_USED bit is not set before pc->mem_cgroup is fixed. 3. at account_move() the page is isolated and not on LRU. Pros. - easy for maintenance. - memcg can make use of laziness of pagevec. - we don't have to duplicated LRU/Active/Unevictable bit in page_cgroup. - LRU status of memcg will be synchronized with global LRU's one. - # of locks are reduced. - account_move() is simplified very much. Cons. - may increase cost of LRU rotation. (no impact if memcg is not configured.) Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08memcg: swap cgroup for remembering usageKAMEZAWA Hiroyuki1-0/+197
For accounting swap, we need a record per swap entry, at least. This patch adds following function. - swap_cgroup_swapon() .... called from swapon - swap_cgroup_swapoff() ... called at the end of swapoff. - swap_cgroup_record() .... record information of swap entry. - swap_cgroup_lookup() .... lookup information of swap entry. This patch just implements "how to record information". No actual method for limit the usage of swap. These routine uses flat table to record and lookup. "wise" lookup system like radix-tree requires requires memory allocation at new records but swap-out is usually called under memory shortage (or memcg hits limit.) So, I used static allocation. (maybe dynamic allocation is not very hard but it adds additional memory allocation in memory shortage path.) Note1: In this, we use pointer to record information and this means 8bytes per swap entry. I think we can reduce this when we create "id of cgroup" in the range of 0-65535 or 0-255. Reported-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Tested-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Reported-by: Hugh Dickins <hugh@veritas.com> Reported-by: Balbir Singh <balbir@linux.vnet.ibm.com> Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Pavel Emelianov <xemul@openvz.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08memcg: do not recalculate section unnecessarily in init_section_page_cgroupFernando Luis Vazquez Cao1-4/+1
In init_section_page_cgroup() the section a given pfn belongs to is calculated at the top of the function and, despite the fact that the pfn/section correspondence does not change, it is recalculated further down the same function. By computing this just once and reusing that value we save some bytes in the object file and do not waste CPU cycles. Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: 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>
2009-01-07mm: make init_section_page_cgroup() staticKOSAKI Motohiro1-1/+1
Sparse output following warning. mm/page_cgroup.c:100:15: warning: symbol 'init_section_page_cgroup' was not declared. Should it be static? cleanup here. Signed-off-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>
2008-12-10page_cgroup should ignore empty nodesKAMEZAWA Hiroyuki1-0/+3
Fix a total bootup freeze on ia64. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Li Zefan <lizf@cn.fujitsu.com> Reported-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-02memcg: memory hotplug fix for notifier callbackKAMEZAWA Hiroyuki1-14/+29
Fixes for memcg/memory hotplug. While memory hotplug allocate/free memmap, page_cgroup doesn't free page_cgroup at OFFLINE when page_cgroup is allocated via bootomem. (Because freeing bootmem requires special care.) Then, if page_cgroup is allocated by bootmem and memmap is freed/allocated by memory hotplug, page_cgroup->page == page is no longer true. But current MEM_ONLINE handler doesn't check it and update page_cgroup->page if it's not necessary to allocate page_cgroup. (This was not found because memmap is not freed if SPARSEMEM_VMEMMAP is y.) And I noticed that MEM_ONLINE can be called against "part of section". So, freeing page_cgroup at CANCEL_ONLINE will cause trouble. (freeing used page_cgroup) Don't rollback at CANCEL. One more, current memory hotplug notifier is stopped by slub because it sets NOTIFY_STOP_MASK to return vaule. So, page_cgroup's callback never be called. (low priority than slub now.) I think this slub's behavior is not intentional(BUG). and fixes it. Another way to be considered about page_cgroup allocation: - free page_cgroup at OFFLINE even if it's from bootmem and remove specieal handler. But it requires more changes. Addresses http://bugzilla.kernel.org/show_bug.cgi?id=12041 Signed-off-by: KAMEZAWA Hiruyoki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Tested-by: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-30meminit section warningsAl Viro1-6/+7
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-13memcg: bugfix for memory hotplugKAMEZAWA Hiroyuki1-2/+2
The start pfn calculation in page_cgroup's memory hotplug notifier chain is wrong. Tested-by: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-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>
2008-10-23memcg: fix page_cgroup allocationKAMEZAWA Hiroyuki1-7/+25
page_cgroup_init() is called from mem_cgroup_init(). But at this point, we cannot call alloc_bootmem(). (and this caused panic at boot.) This patch moves page_cgroup_init() to init/main.c. Time table is following: == parse_args(). # we can trust mem_cgroup_subsys.disabled bit after this. .... cgroup_init_early() # "early" init of cgroup. .... setup_arch() # memmap is allocated. ... page_cgroup_init(); mem_init(); # we cannot call alloc_bootmem after this. .... cgroup_init() # mem_cgroup is initialized. == Before page_cgroup_init(), mem_map must be initialized. So, I added page_cgroup_init() to init/main.c directly. (*) maybe this is not very clean but - cgroup_init_early() is too early - in cgroup_init(), we have to use vmalloc instead of alloc_bootmem(). use of vmalloc area in x86-32 is important and we should avoid very large vmalloc() in x86-32. So, we want to use alloc_bootmem() and added page_cgroup_init() directly to init/main.c [akpm@linux-foundation.org: remove unneeded/bad mem_cgroup_subsys declaration] [akpm@linux-foundation.org: fix build] Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-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>
2008-10-23mm: page_cgroup needs linux/vmalloc.h for vmalloc_node()/vfree().Paul Mundt1-0/+1
mm/page_cgroup.c: In function 'init_section_page_cgroup': mm/page_cgroup.c:111: error: implicit declaration of function 'vmalloc_node' mm/page_cgroup.c:111: warning: assignment makes pointer from integer without a cast mm/page_cgroup.c: In function '__free_page_cgroup': mm/page_cgroup.c:140: error: implicit declaration of function 'vfree' Signed-off-by: Paul Mundt <lethal@linux-sh.org> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-20memcg: allocate all page_cgroup at bootKAMEZAWA Hiroyuki1-0/+237
Allocate all page_cgroup at boot and remove page_cgroup poitner from struct page. This patch adds an interface as struct page_cgroup *lookup_page_cgroup(struct page*) All FLATMEM/DISCONTIGMEM/SPARSEMEM and MEMORY_HOTPLUG is supported. Remove page_cgroup pointer reduces the amount of memory by - 4 bytes per PAGE_SIZE. - 8 bytes per PAGE_SIZE if memory controller is disabled. (even if configured.) On usual 8GB x86-32 server, this saves 8MB of NORMAL_ZONE memory. On my x86-64 server with 48GB of memory, this saves 96MB of memory. I think this reduction makes sense. By pre-allocation, kmalloc/kfree in charge/uncharge are removed. This means - we're not necessary to be afraid of kmalloc faiulre. (this can happen because of gfp_mask type.) - we can avoid calling kmalloc/kfree. - we can avoid allocating tons of small objects which can be fragmented. - we can know what amount of memory will be used for this extra-lru handling. I added printk message as "allocated %ld bytes of page_cgroup" "please try cgroup_disable=memory option if you don't want" maybe enough informative for users. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-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>