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* memcg: close race between charge and putbackJohannes Weiner2011-11-031-1/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | There is a potential race between a thread charging a page and another thread putting it back to the LRU list: charge: putback: SetPageCgroupUsed SetPageLRU PageLRU && add to memcg LRU PageCgroupUsed && add to memcg LRU The order of setting one flag and checking the other is crucial, otherwise the charge may observe !PageLRU while the putback observes !PageCgroupUsed and the page is not linked to the memcg LRU at all. Global memory pressure may fix this by trying to isolate and putback the page for reclaim, where that putback would link it to the memcg LRU again. Without that, the memory cgroup is undeletable due to a charge whose physical page can not be found and moved out. Signed-off-by: Johannes Weiner <jweiner@redhat.com> Cc: Ying Han <yinghan@google.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: skip scanning active lists based on individual sizeJohannes Weiner2011-11-034-41/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reclaim decides to skip scanning an active list when the corresponding inactive list is above a certain size in comparison to leave the assumed working set alone while there are still enough reclaim candidates around. The memcg implementation of comparing those lists instead reports whether the whole memcg is low on the requested type of inactive pages, considering all nodes and zones. This can lead to an oversized active list not being scanned because of the state of the other lists in the memcg, as well as an active list being scanned while its corresponding inactive list has enough pages. Not only is this wrong, it's also a scalability hazard, because the global memory state over all nodes and zones has to be gathered for each memcg and zone scanned. Make these calculations purely based on the size of the two LRU lists that are actually affected by the outcome of the decision. Signed-off-by: Johannes Weiner <jweiner@redhat.com> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: Ying Han <yinghan@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: do not expose uninitialized mem_cgroup_per_node to worldIgor Mammedov2011-11-031-1/+1
| | | | | | | | | | | | If somebody is touching data too early, it might be easier to diagnose a problem when dereferencing NULL at mem->info.nodeinfo[node] than trying to understand why mem_cgroup_per_zone is [un|partly]initialized. Signed-off-by: Igor Mammedov <imammedo@redhat.com> Acked-by: Michal Hocko <mhocko@suse.cz> 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>
* memcg: fix oom schedule_timeout()KAMEZAWA Hiroyuki2011-11-031-1/+1
| | | | | | | | | Before calling schedule_timeout(), task state should be changed. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.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>
* memcg: rename mem variable to memcgRaghavendra K T2011-11-032-479/+485
| | | | | | | | | | | | The memcg code sometimes uses "struct mem_cgroup *mem" and sometimes uses "struct mem_cgroup *memcg". Rename all mem variables to memcg in source file. Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.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>
* cgroup/kmemleak: Annotate alloc_page() for cgroup allocationsSteven Rostedt2011-11-031-2/+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>
* cgroups: don't attach task to subsystem if migration failedBen Blum2011-11-031-6/+9
| | | | | | | | | | | | | | | | | | | | | | | | | If a task has exited to the point it has called cgroup_exit() already, then we can't migrate it to another cgroup anymore. This can happen when we are attaching a task to a new cgroup between the call to ->can_attach_task() on subsystems and the migration that is eventually tried in cgroup_task_migrate(). In this case cgroup_task_migrate() returns -ESRCH and we don't want to attach the task to the subsystems because the attachment to the new cgroup itself failed. Fix this by only calling ->attach_task() on the subsystems if the cgroup migration succeeded. Reported-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Ben Blum <bblum@andrew.cmu.edu> Acked-by: Paul Menage <paul@paulmenage.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cgroups: more safe tasklist locking in cgroup_attach_procBen Blum2011-11-031-3/+3
| | | | | | | | | | | | | | | | | | Fix unstable tasklist locking in cgroup_attach_proc. According to this thread - https://lkml.org/lkml/2011/7/27/243 - RCU is not sufficient to guarantee the tasklist is stable w.r.t. de_thread and exit. Taking tasklist_lock for reading, instead of rcu_read_lock, ensures proper exclusion. Signed-off-by: Ben Blum <bblum@andrew.cmu.edu> Acked-by: Paul Menage <paul@paulmenage.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hfs: fix hfs_find_init() sb->ext_tree NULL ptr oopsPhillip Lougher2011-11-031-5/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Clement Lecigne reports a filesystem which causes a kernel oops in hfs_find_init() trying to dereference sb->ext_tree which is NULL. This proves to be because the filesystem has a corrupted MDB extent record, where the extents file does not fit into the first three extents in the file record (the first blocks). In hfs_get_block() when looking up the blocks for the extent file (HFS_EXT_CNID), it fails the first blocks special case, and falls through to the extent code (which ultimately calls hfs_find_init()) which is in the process of being initialised. Hfs avoids this scenario by always having the extents b-tree fitting into the first blocks (the extents B-tree can't have overflow extents). The fix is to check at mount time that the B-tree fits into first blocks, i.e. fail if HFS_I(inode)->alloc_blocks >= HFS_I(inode)->first_blocks Note, the existing commit 47f365eb57573 ("hfs: fix oops on mount with corrupted btree extent records") becomes subsumed into this as a special case, but only for the extents B-tree (HFS_EXT_CNID), it is perfectly acceptable for the catalog B-Tree file to grow beyond three extents, with the remaining extent descriptors in the extents overfow. This fixes CVE-2011-2203 Reported-by: Clement LECIGNE <clement.lecigne@netasq.com> Signed-off-by: Phillip Lougher <plougher@redhat.com> Cc: Jeff Mahoney <jeffm@suse.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* isofs: add readpages supportNamjae Jeon2011-11-031-1/+9
| | | | | | | | | | | Use mpage_readpages() instead of multiple calls to isofs_readpage() to reduce the CPU utilization and make performance higher. Signed-off-by: Namjae Jeon <linkinjeon@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* minix: describe usage of different magic numbersSami Kerola2011-11-031-5/+5
| | | | | | | | | One can get this information from minix/inode.c, but adding the explanations at the definition sites is more appropriate. Signed-off-by: Sami Kerola <kerolasa@iki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* drivers/rtc/rtc-mc13xxx.c: move probe and remove callbacks to .init.text and ↵Uwe Kleine-König2011-11-031-3/+3
| | | | | | | | | | | | .exit.text The driver is added using platform_driver_probe(), so the callbacks can be discarded more aggessively. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* rtc: add initial support for mcp7941x partsDavid Anders2011-11-031-0/+27
| | | | | | | | | | | | | | Add initial support for the microchip mcp7941x series of real time clocks. The mcp7941x series is generally compatible with the ds1307 and ds1337 rtc devices from dallas semiconductor. minor differences include a backup battery enable bit, and the polarity of the oscillator enable bit. Signed-off-by: David Anders <danders.dev@gmail.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Reviewed-by: Wolfram Sang <w.sang@pengutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* drivers/rtc/class.c: convert idr to ida and use ida_simple_get()Jonathan Cameron2011-11-031-23/+9
| | | | | | | | | | This is the one use of an ida that doesn't retry on receiving -EAGAIN. I'm assuming do so will cause no harm and may help on a rare occasion. Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* init/do_mounts_rd.c: fix ramdisk identification for padded cramfsNeil Armstrong2011-11-031-0/+14
| | | | | | | | | | | | | | When a cramfs ramdisk padded with 512 bytes is given to the kernel, the current identify_ramdisk_image function fails to identify it. Tested with a padded cramfs image on an ARM based board. Signed-off-by: Neil Armstrong <narmstrong@neotion.com> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Davidlohr Bueso <dave@gnu.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ramfs: remove module leftoversRichard Weinberger2011-11-031-10/+0
| | | | | | | | | | | Since ramfs is hard-selected to "y", the module leftovers make no sense. Signed-off-by: Richard Weinberger <richard@nod.at> Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* binfmt_elf: fix PIE execution with randomization disabledJiri Kosina2011-11-031-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | The case of address space randomization being disabled in runtime through randomize_va_space sysctl is not treated properly in load_elf_binary(), resulting in SIGKILL coming at exec() time for certain PIE-linked binaries in case the randomization has been disabled at runtime prior to calling exec(). Handle the randomize_va_space == 0 case the same way as if we were not supporting .text randomization at all. Based on original patch by H.J. Lu and Josh Boyer. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Cc: Ingo Molnar <mingo@elte.hu> Cc: Russell King <rmk@arm.linux.org.uk> Cc: H.J. Lu <hongjiu.lu@intel.com> Cc: <stable@kernel.org> Tested-by: Josh Boyer <jwboyer@redhat.com> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* thp: share get_huge_page_tail()Andrea Arcangeli2011-11-035-44/+11
| | | | | | | | | | | | | | | | | | | This avoids duplicating the function in every arch gup_fast. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sparc: gup_pte_range() support THP based tail recountingAndrea Arcangeli2011-11-031-0/+13
| | | | | | | | | | | | | | | | | | | | Up to this point the code assumed old refcounting for hugepages (pre-thp). This updates the code directly to the thp mapcount tail page refcounting. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* s390: gup_huge_pmd() return 0 if pte changesAndrea Arcangeli2011-11-031-10/+11
| | | | | | | | | | | | | | | | | | | | | s390 didn't return 0 in that case, if it's rolling back the *nr pointer it should also return zero to avoid adding pages to the array at the wrong offset. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* s390: gup_huge_pmd() support THP tail recountingAndrea Arcangeli2011-11-031-1/+23
| | | | | | | | | | | | | | | | | | | | Up to this point the code assumed old refcounting for hugepages (pre-thp). This updates the code directly to the thp mapcount tail page refcounting. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* powerpc: gup_huge_pmd() return 0 if pte changesAndrea Arcangeli2011-11-031-10/+11
| | | | | | | | | | | | | | | | | | | | | powerpc didn't return 0 in that case, if it's rolling back the *nr pointer it should also return zero to avoid adding pages to the array at the wrong offset. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: David Gibson <david@gibson.dropbear.id.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* powerpc: gup_hugepte() support THP based tail recountingAndrea Arcangeli2011-11-031-1/+23
| | | | | | | | | | | | | | | | | Up to this point the code assumed old refcounting for hugepages (pre-thp). This updates the code directly to the thp mapcount tail page refcounting. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* powerpc: gup_hugepte() avoid freeing the head page too many timesAndrea Arcangeli2011-11-031-3/+2
| | | | | | | | | | | | | | | | We only taken "refs" pins on the head page not "*nr" pins. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* powerpc: get_hugepte() don't put_page() the wrong pageAndrea Arcangeli2011-11-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | "page" may have changed to point to the next hugepage after the loop completed, The references have been taken on the head page, so the put_page must happen there too. This is a longstanding issue pre-thp inclusion. It's totally unclear how these page_cache_add_speculative and pte_val(pte) != pte_val(*ptep) checks are necessary across all the powerpc gup_fast code, when x86 doesn't need any of that: there's no way the page can be freed with irq disabled so we're guaranteed the atomic_inc will happen on a page with page_count > 0 (so not needing the speculative check). The pte check is also meaningless on x86: no need to rollback on x86 if the pte changed, because the pte can still change a CPU tick after the check succeeded and it won't be rolled back in that case. The important thing is we got a reference on a valid page that was mapped there a CPU tick ago. So not knowing the soft tlb refill code of ppc64 in great detail I'm not removing the "speculative" page_count increase and the pte checks across all the code, but unless there's a strong reason for it they should be later cleaned up too. If a pte can change from huge to non-huge (like it could happen with THP) passing a pte_t *ptep to gup_hugepte() would also require to repeat the is_hugepd in gup_hugepte(), but that shouldn't happen with hugetlbfs only so I'm not altering that. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* powerpc: remove superfluous PageTail checks on the pte gup_fastAndrea Arcangeli2011-11-031-13/+0
| | | | | | | | | | | | | | | | | | | | | | This part of gup_fast doesn't seem capable of handling hugetlbfs ptes, those should be handled by gup_hugepd only, so these checks are superfluous. Plus if this wasn't a noop, it would have oopsed because, the insistence of using the speculative refcounting would trigger a VM_BUG_ON if a tail page was encountered in the page_cache_get_speculative(). Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: thp: tail page refcounting fixAndrea Arcangeli2011-11-038-84/+171
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Michel while working on the working set estimation code, noticed that calling get_page_unless_zero() on a random pfn_to_page(random_pfn) wasn't safe, if the pfn ended up being a tail page of a transparent hugepage under splitting by __split_huge_page_refcount(). He then found the problem could also theoretically materialize with page_cache_get_speculative() during the speculative radix tree lookups that uses get_page_unless_zero() in SMP if the radix tree page is freed and reallocated and get_user_pages is called on it before page_cache_get_speculative has a chance to call get_page_unless_zero(). So the best way to fix the problem is to keep page_tail->_count zero at all times. This will guarantee that get_page_unless_zero() can never succeed on any tail page. page_tail->_mapcount is guaranteed zero and is unused for all tail pages of a compound page, so we can simply account the tail page references there and transfer them to tail_page->_count in __split_huge_page_refcount() (in addition to the head_page->_mapcount). While debugging this s/_count/_mapcount/ change I also noticed get_page is called by direct-io.c on pages returned by get_user_pages. That wasn't entirely safe because the two atomic_inc in get_page weren't atomic. As opposed to other get_user_page users like secondary-MMU page fault to establish the shadow pagetables would never call any superflous get_page after get_user_page returns. It's safer to make get_page universally safe for tail pages and to use get_page_foll() within follow_page (inside get_user_pages()). get_page_foll() is safe to do the refcounting for tail pages without taking any locks because it is run within PT lock protected critical sections (PT lock for pte and page_table_lock for pmd_trans_huge). The standard get_page() as invoked by direct-io instead will now take the compound_lock but still only for tail pages. The direct-io paths are usually I/O bound and the compound_lock is per THP so very finegrined, so there's no risk of scalability issues with it. A simple direct-io benchmarks with all lockdep prove locking and spinlock debugging infrastructure enabled shows identical performance and no overhead. So it's worth it. Ideally direct-io should stop calling get_page() on pages returned by get_user_pages(). The spinlock in get_page() is already optimized away for no-THP builds but doing get_page() on tail pages returned by GUP is generally a rare operation and usually only run in I/O paths. This new refcounting on page_tail->_mapcount in addition to avoiding new RCU critical sections will also allow the working set estimation code to work without any further complexity associated to the tail page refcounting with THP. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reported-by: Michel Lespinasse <walken@google.com> Reviewed-by: Michel Lespinasse <walken@google.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: <stable@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'next/soc' of git://git.linaro.org/people/arnd/arm-socLinus Torvalds2011-11-0281-14/+5778
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'next/soc' of git://git.linaro.org/people/arnd/arm-soc: (21 commits) MAINTAINERS: add ARM/FREESCALE IMX6 entry arm/imx: merge i.MX3 and i.MX6 arm/imx6q: add suspend/resume support arm/imx6q: add device tree machine support arm/imx6q: add smp and cpu hotplug support arm/imx6q: add core drivers clock, gpc, mmdc and src arm/imx: add gic_handle_irq function arm/imx6q: add core definitions and low-level debug uart arm/imx6q: add device tree source ARM: highbank: add suspend support ARM: highbank: Add cpu hotplug support ARM: highbank: add SMP support MAINTAINERS: add Calxeda Highbank ARM platform ARM: add Highbank core platform support ARM: highbank: add devicetree source ARM: l2x0: add empty l2x0_of_init picoxcell: add a definition of VMALLOC_END picoxcell: remove custom ioremap implementation picoxcell: add the DTS for the PC7302 board picoxcell: add the DTS for pc3x2 and pc3x3 devices ... Fix up trivial conflicts in arch/arm/Kconfig, and some more header file conflicts in arch/arm/mach-omap2/board-generic.c (as per an ealier merge by Arnd).
| * Merge branch 'imx/imx6q' into next/socArnd Bergmann2011-11-0234-80/+3662
| |\ | | | | | | | | | | | | | | | | | | | | | Conflicts: Documentation/devicetree/bindings/arm/fsl.txt arch/arm/Kconfig arch/arm/Kconfig.debug arch/arm/plat-mxc/include/mach/common.h
| | * MAINTAINERS: add ARM/FREESCALE IMX6 entryShawn Guo2011-10-311-0/+7
| | | | | | | | | | | | | | | | | | It adds maintainer for ARM/FREESCALE IMX6. Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
| | * arm/imx: merge i.MX3 and i.MX6Sascha Hauer2011-10-314-19/+13
| | | | | | | | | | | | | | | | | | | | | | | | The patch merges the build of imx3 and imx6. The Kconfig symbol ARCH_IMX_V6_V7 is introduced to replace ARCH_MX3 and ARCH_MX6. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
| | * arm/imx6q: add suspend/resume supportShawn Guo2011-10-314-1/+108
| | | | | | | | | | | | | | | | | | | | | It adds suspend/resume support for imx6q. Signed-off-by: Anson Huang <b20788@freescale.com> Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
| | * arm/imx6q: add device tree machine supportShawn Guo2011-10-314-2/+99
| | | | | | | | | | | | | | | | | | It adds generic device tree based machine support for imx6q. Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
| | * arm/imx6q: add smp and cpu hotplug supportShawn Guo2011-10-317-0/+246
| | | | | | | | | | | | | | | | | | It adds smp and cpu hotplug support for imx6q. Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
| | * arm/imx6q: add core drivers clock, gpc, mmdc and srcShawn Guo2011-10-316-0/+2263
| | | | | | | | | | | | | | | | | | | | | | | | | | | It adds a number of core drivers support for imx6q, including clock, General Power Controller (gpc), Multi Mode DDR Controller(mmdc) and System Reset Controller (src). Signed-off-by: Ranjani Vaidyanathan <ra5478@freescale.com> Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
| | * arm/imx: add gic_handle_irq functionShawn Guo2011-10-314-1/+57
| | | | | | | | | | | | | | | | | | | | | This is a plain translation of assembly gic irq handler to C function for CONFIG_MULTI_IRQ_HANDLER support on imx family. Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
| | * arm/imx6q: add core definitions and low-level debug uartShawn Guo2011-10-3112-3/+118
| | | | | | | | | | | | | | | | | | | | | It adds the core definitions and low-level debug uart support for imx6q. Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
| | * arm/imx6q: add device tree sourceShawn Guo2011-10-313-0/+643
| | | | | | | | | | | | | | | | | | It adds device tree source and documentation for imx6q platform. Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
| | * Merge branch 'cross-platform/debug_ll' into imx/imx6qArnd Bergmann2011-10-315-69/+122
| | |\ | | | | | | | | | | | | | | | | Conflicts: arch/arm/Kconfig.debug
| | * \ Merge branch 'imx/devel' into imx/imx6qArnd Bergmann2011-10-31137-5256/+4008
| | |\ \ | | | | | | | | | | | | | | | | | | | | Conflicts: arch/arm/plat-mxc/include/mach/memory.h
| | * \ \ Merge branch 'dt/gic' into imx/imx6qArnd Bergmann2011-10-31157-1513/+1177
| | |\ \ \
| | * \ \ \ Merge branch 'depends/rmk/devel-stable' into imx/imx6qArnd Bergmann2011-10-31406-1550/+7175
| | |\ \ \ \
| | * \ \ \ \ Merge branch 'depends/rmk/smp' into tmpArnd Bergmann2011-10-2016-13/+298
| | |\ \ \ \ \
| | * \ \ \ \ \ Merge branch 'depends/rmk/debug' into tmpArnd Bergmann2011-10-201-30/+59
| | |\ \ \ \ \ \
| * | \ \ \ \ \ \ Merge branch 'picoxcell/soc' into next/socArnd Bergmann2011-11-0226-0/+1341
| |\ \ \ \ \ \ \ \
| | * | | | | | | | picoxcell: add a definition of VMALLOC_ENDJamie Iles2011-10-041-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Nicolas Pitre's vmalloc cleanup series didn't get merged in this cycle so picoxcell is missing a VMALLOC_END definition. Signed-off-by: Jamie Iles <jamie@jamieiles.com>
| | * | | | | | | | picoxcell: remove custom ioremap implementationJamie Iles2011-09-263-49/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Nicolas Pitre's generic ioremap() patch set means that we don't need this any more. Signed-off-by: Jamie Iles <jamie@jamieiles.com>
| | * | | | | | | | picoxcell: add the DTS for the PC7302 boardJamie Iles2011-09-262-0/+178
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The PC7302 board can be populated with either a PC3X2 or PC3X3 device. Add DTS files for both variants of the PC7302. v3: - remove bootargs from dts files Signed-off-by: Jamie Iles <jamie@jamieiles.com>
| | * | | | | | | | picoxcell: add the DTS for pc3x2 and pc3x3 devicesJamie Iles2011-09-262-0/+614
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This describes the basic hierarchy of picoxcell pc3x3 devices including clocks and bus interconnect. Some onchip devices are currently omitted as there haven't been bindings created for them. v2: - change timer compatible strings to be more soc specific - split vic node into 2 devices Signed-off-by: Jamie Iles <jamie@jamieiles.com>
| | * | | | | | | | picoxcell: support for Picochip picoxcell devicesJamie Iles2011-09-2622-0/+584
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | picoXcell is a family of femtocell devices with an ARM application processor and picoArray DSP processor array. This patch adds support for picoXcell boards to be booted using the device tree registering the VIC's, UART's and timers. v3: - fixup vic compatible string in binding v2: - cleanup empty mach headers - convert to of_platform_populate() - simplify uncompress.h - split vic node into 2 devices - add missing __initconst attributes Signed-off-by: Jamie Iles <jamie@jamieiles.com>
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