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2010-08-10vt/console: try harder to print output when panicingJesse Barnes
Jesse's initial patch commit said: "At panic time (i.e. when oops_in_progress is set) we should try a bit harder to update the screen and make sure output gets to the VT, since some drivers are capable of flipping back to it. So make sure we try to unblank and update the display if called from a panic context." I've enhanced this to add a flag to the vc that console layer can set to indicate they want this behaviour to occur. This also adds support to fbcon for that flag and adds an fb flag for drivers to indicate they want to use the support. It enables this for KMS drivers. Signed-off-by: Dave Airlie <airlied@redhat.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> Acked-by: James Simmons <jsimmons@infradead.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-10tty: Add EXTPROC support for LINEMODEhyc@symas.com
This patch is against the 2.6.34 source. Paraphrased from the 1989 BSD patch by David Borman @ cray.com: These are the changes needed for the kernel to support LINEMODE in the server. There is a new bit in the termios local flag word, EXTPROC. When this bit is set, several aspects of the terminal driver are disabled. Input line editing, character echo, and mapping of signals are all disabled. This allows the telnetd to turn off these functions when in linemode, but still keep track of what state the user wants the terminal to be in. New ioctl: TIOCSIG Generate a signal to processes in the current process group of the pty. There is a new mode for packet driver, the TIOCPKT_IOCTL bit. When packet mode is turned on in the pty, and the EXTPROC bit is set, then whenever the state of the pty is changed, the next read on the master side of the pty will have the TIOCPKT_IOCTL bit set. This allows the process on the server side of the pty to know when the state of the terminal has changed; it can then issue the appropriate ioctl to retrieve the new state. Since the original BSD patches accompanied the source code for telnet I've left that reference here, but obviously the feature is useful for any remote terminal protocol, including ssh. The corresponding feature has existed in the BSD tty driver since 1989. For historical reference, a good copy of the relevant files can be found here: http://anonsvn.mit.edu/viewvc/krb5/trunk/src/appl/telnet/?pathrev=17741 Signed-off-by: Howard Chu <hyc@symas.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-10Merge branch 'writable_limits' of git://decibel.fi.muni.cz/~xslaby/linuxLinus Torvalds
* 'writable_limits' of git://decibel.fi.muni.cz/~xslaby/linux: unistd: add __NR_prlimit64 syscall numbers rlimits: implement prlimit64 syscall rlimits: switch more rlimit syscalls to do_prlimit rlimits: redo do_setrlimit to more generic do_prlimit rlimits: add rlimit64 structure rlimits: do security check under task_lock rlimits: allow setrlimit to non-current tasks rlimits: split sys_setrlimit rlimits: selinux, do rlimits changes under task_lock rlimits: make sure ->rlim_max never grows in sys_setrlimit rlimits: add task_struct to update_rlimit_cpu rlimits: security, add task_struct to setrlimit Fix up various system call number conflicts. We not only added fanotify system calls in the meantime, but asm-generic/unistd.h added a wait4 along with a range of reserved per-architecture system calls.
2010-08-10Merge git://git.infradead.org/mtd-2.6Linus Torvalds
* git://git.infradead.org/mtd-2.6: (79 commits) mtd: Remove obsolete <mtd/compatmac.h> include mtd: Update copyright notices jffs2: Update copyright notices mtd-physmap: add support users can assign the probe type in board files mtd: remove redwood map driver mxc_nand: Add v3 (i.MX51) Support mxc_nand: support 8bit ecc mxc_nand: fix correct_data function mxc_nand: add V1_V2 namespace to registers mxc_nand: factor out a check_int function mxc_nand: make some internally used functions overwriteable mxc_nand: rework get_dev_status mxc_nand: remove 0xe00 offset from registers mtd: denali: Add multi connected NAND support mtd: denali: Remove set_ecc_config function mtd: denali: Remove unuseful code in get_xx_nand_para functions mtd: denali: Remove device_info_tag structure mtd: m25p80: add support for the Winbond W25Q32 SPI flash chip mtd: m25p80: add support for the Intel/Numonyx {16,32,64}0S33B SPI flash chips mtd: m25p80: add support for the EON EN25P{32, 64} SPI flash chips ... Fix up trivial conflicts in drivers/mtd/maps/{Kconfig,redwood.c} due to redwood driver removal.
2010-08-10Merge branch 'for-linus' of git://git.infradead.org/users/eparis/notifyLinus Torvalds
* 'for-linus' of git://git.infradead.org/users/eparis/notify: (132 commits) fanotify: use both marks when possible fsnotify: pass both the vfsmount mark and inode mark fsnotify: walk the inode and vfsmount lists simultaneously fsnotify: rework ignored mark flushing fsnotify: remove global fsnotify groups lists fsnotify: remove group->mask fsnotify: remove the global masks fsnotify: cleanup should_send_event fanotify: use the mark in handler functions audit: use the mark in handler functions dnotify: use the mark in handler functions inotify: use the mark in handler functions fsnotify: send fsnotify_mark to groups in event handling functions fsnotify: Exchange list heads instead of moving elements fsnotify: srcu to protect read side of inode and vfsmount locks fsnotify: use an explicit flag to indicate fsnotify_destroy_mark has been called fsnotify: use _rcu functions for mark list traversal fsnotify: place marks on object in order of group memory address vfs/fsnotify: fsnotify_close can delay the final work in fput fsnotify: store struct file not struct path ... Fix up trivial delete/modify conflict in fs/notify/inotify/inotify.c.
2010-08-10Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (96 commits) no need for list_for_each_entry_safe()/resetting with superblock list Fix sget() race with failing mount vfs: don't hold s_umount over close_bdev_exclusive() call sysv: do not mark superblock dirty on remount sysv: do not mark superblock dirty on mount btrfs: remove junk sb_dirt change BFS: clean up the superblock usage AFFS: wait for sb synchronization when needed AFFS: clean up dirty flag usage cifs: truncate fallout mbcache: fix shrinker function return value mbcache: Remove unused features add f_flags to struct statfs(64) pass a struct path to vfs_statfs update VFS documentation for method changes. All filesystems that need invalidate_inode_buffers() are doing that explicitly convert remaining ->clear_inode() to ->evict_inode() Make ->drop_inode() just return whether inode needs to be dropped fs/inode.c:clear_inode() is gone fs/inode.c:evict() doesn't care about delete vs. non-delete paths now ... Fix up trivial conflicts in fs/nilfs2/super.c
2010-08-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (59 commits) igbvf.txt: Add igbvf Documentation igb.txt: Add igb documentation e100/e1000*/igb*/ixgb*: Add missing read memory barrier ixgbe: fix build error with FCOE_CONFIG without DCB_CONFIG netxen: protect tx timeout recovery by rtnl lock isdn: gigaset: use after free isdn: gigaset: add missing unlock solos-pci: Fix race condition in tasklet RX handling pkt_sched: Fix sch_sfq vs tcf_bind_filter oops net: disable preemption before call smp_processor_id() tcp: no md5sig option size check bug iwlwifi: fix locking assertions iwlwifi: fix TX tracer isdn: fix information leak net: Fix napi_gro_frags vs netpoll path usbnet: remove noisy and hardly useful printk rtl8180: avoid potential NULL deref in rtl8180_beacon_work ath9k: Remove myself from the MAINTAINERS list libertas: scan before assocation if no BSSID was given libertas: fix association with some APs by using extended rates ...
2010-08-09Merge branch 'next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx: (30 commits) DMAENGINE: at_hdmac: locking fixlet DMAENGINE: pch_dma: kill another usage of __raw_{read|write}l dma: dmatest: fix potential sign bug ioat2: catch and recover from broken vtd configurations v6 DMAENGINE: add runtime slave control to COH 901 318 v3 DMAENGINE: add runtime slave config to DMA40 v3 DMAENGINE: generic slave channel control v3 dmaengine: Driver for Topcliff PCH DMA controller intel_mid: Add Mrst & Mfld DMA Drivers drivers/dma: Eliminate a NULL pointer dereference dma/timb_dma: compile warning on 32 bit DMAENGINE: ste_dma40: support older silicon DMAENGINE: ste_dma40: support disabling physical channels DMAENGINE: ste_dma40: no disabled phy channels on ux500 DMAENGINE: ste_dma40: fix suspend bug DMAENGINE: ste_dma40: add DB8500 memcpy channels DMAENGINE: ste_dma40: no flow control on memcpy DMAENGINE: ste_dma40: arch updates for LCLA and LCPA DMAENGINE: ste_dma40: allocate LCLA dynamically DMAENGINE: ste_dma40: no premature stop ... Fix up trivial conflicts in arch/arm/mach-ux500/devices-db8500.c
2010-08-09flex_array: add helpers to get and put to make pointers easy to useEric Paris
Getting and putting arrays of pointers with flex arrays is a PITA. You have to remember to pass &ptr to the _put and you have to do weird and wacky casting to get the ptr back from the _get. Add two functions flex_array_get_ptr() and flex_array_put_ptr() to handle all of the magic. [akpm@linux-foundation.org: simplification suggested by Joe] Signed-off-by: Eric Paris <eparis@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Cc: Joe Perches <joe@perches.com> Cc: James Morris <jmorris@namei.org> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09iommu: inline iommu_num_pagesAnton Blanchard
A profile of a network benchmark showed iommu_num_pages rather high up: 0.52% iommu_num_pages Looking at the profile, an integer divide is taking almost all of the time: % : c000000000376ea4 <.iommu_num_pages>: 1.93 : c000000000376ea4: fb e1 ff f8 std r31,-8(r1) 0.00 : c000000000376ea8: f8 21 ff c1 stdu r1,-64(r1) 0.00 : c000000000376eac: 7c 3f 0b 78 mr r31,r1 3.86 : c000000000376eb0: 38 84 ff ff addi r4,r4,-1 0.00 : c000000000376eb4: 38 05 ff ff addi r0,r5,-1 0.00 : c000000000376eb8: 7c 84 2a 14 add r4,r4,r5 46.95 : c000000000376ebc: 7c 00 18 38 and r0,r0,r3 45.66 : c000000000376ec0: 7c 84 02 14 add r4,r4,r0 0.00 : c000000000376ec4: 7c 64 2b 92 divdu r3,r4,r5 0.00 : c000000000376ec8: 38 3f 00 40 addi r1,r31,64 0.00 : c000000000376ecc: eb e1 ff f8 ld r31,-8(r1) 1.61 : c000000000376ed0: 4e 80 00 20 blr Since every caller of iommu_num_pages passes in a constant power of two we can inline this such that the divide is replaced by a shift. The entire function is only a few instructions once optimised, so it is a good candidate for inlining overall. Signed-off-by: Anton Blanchard <anton@samba.org> Cc: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09kernel.h: remove unused NIPQUAD and NIPQUAD_FMTJoe Perches
There are no more uses of NIPQUAD or NIPQUAD_FMT. Remove the definitions. Signed-off-by: Joe Perches <joe@perches.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09include/linux/compiler-gcc.h: use __same_type() in __must_be_array()Rusty Russell
We should use the __same_type() helper in __must_be_array(). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09cpuidle: extend cpuidle and menu governor to handle dynamic statesAi Li
On some SoC chips, HW resources may be in use during any particular idle period. As a consequence, the cpuidle states that the SoC is safe to enter can change from idle period to idle period. In addition, the latency and threshold of each cpuidle state can vary, depending on the operating condition when the CPU becomes idle, e.g. the current cpu frequency, the current state of the HW blocks, etc. cpuidle core and the menu governor, in the current form, are geared towards cpuidle states that are static, i.e. the availabiltiy of the states, their latencies, their thresholds are non-changing during run time. cpuidle does not provide any hook that cpuidle drivers can use to adjust those values on the fly for the current idle period before the menu governor selects the target cpuidle state. This patch extends cpuidle core and the menu governor to handle states that are dynamic. There are three additions in the patch and the patch maintains backwards-compatibility with existing cpuidle drivers. 1) add prepare() to struct cpuidle_device. A cpuidle driver can hook into the callback and cpuidle will call prepare() before calling the governor's select function. The callback gives the cpuidle driver a chance to update the dynamic information of the cpuidle states for the current idle period, e.g. state availability, latencies, thresholds, power values, etc. 2) add CPUIDLE_FLAG_IGNORE as one of the state flags. In the prepare() function, a cpuidle driver can set/clear the flag to indicate to the menu governor whether a cpuidle state should be ignored, i.e. not available, during the current idle period. 3) add power_specified bit to struct cpuidle_device. The menu governor currently assumes that the cpuidle states are arranged in the order of increasing latency, threshold, and power savings. This is true or can be made true for static states. Once the state parameters are dynamic, the latencies, thresholds, and power savings for the cpuidle states can increase or decrease by different amounts from idle period to idle period. So the assumption of increasing latency, threshold, and power savings from Cn to C(n+1) can no longer be guaranteed. It can be straightforward to calculate the power consumption of each available state and to specify it in power_usage for the idle period. Using the power_usage fields, the menu governor then selects the state that has the lowest power consumption and that still satisfies all other critieria. The power_specified bit defaults to 0. For existing cpuidle drivers, cpuidle detects that power_specified is 0 and fills in a dummy set of power_usage values. Signed-off-by: Ai Li <aili@codeaurora.org> Cc: Len Brown <len.brown@intel.com> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09hibernation: freeze swap at hibernationKAMEZAWA Hiroyuki
When taking a memory snapshot in hibernate_snapshot(), all (directly called) memory allocations use GFP_ATOMIC. Hence swap misusage during hibernation never occurs. But from a pessimistic point of view, there is no guarantee that no page allcation has __GFP_WAIT. It is better to have a global indication "we enter hibernation, don't use swap!". This patch tries to freeze new-swap-allocation during hibernation. (All user processes are frozenm so swapin is not a concern). This way, no updates will happen to swap_map[] between hibernate_snapshot() and save_image(). Swap is thawed when swsusp_free() is called. We can be assured that swap corruption will not occur. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Hugh Dickins <hughd@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Ondrej Zary <linux@rainbow-software.org> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09rmap: add exclusive page to private anon_vma on swapinRik van Riel
On swapin it is fairly common for a page to be owned exclusively by one process. In that case we want to add the page to the anon_vma of that process's VMA, instead of to the root anon_vma. This will reduce the amount of rmap searching that the swapout code needs to do. Signed-off-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.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>
2010-08-09oom: deprecate oom_adj tunableDavid Rientjes
/proc/pid/oom_adj is now deprecated so that that it may eventually be removed. The target date for removal is August 2012. A warning will be printed to the kernel log if a task attempts to use this interface. Future warning will be suppressed until the kernel is rebooted to prevent spamming the kernel log. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.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>
2010-08-09oom: badness heuristic rewriteDavid Rientjes
This a complete rewrite of the oom killer's badness() heuristic which is used to determine which task to kill in oom conditions. The goal is to make it as simple and predictable as possible so the results are better understood and we end up killing the task which will lead to the most memory freeing while still respecting the fine-tuning from userspace. Instead of basing the heuristic on mm->total_vm for each task, the task's rss and swap space is used instead. This is a better indication of the amount of memory that will be freeable if the oom killed task is chosen and subsequently exits. This helps specifically in cases where KDE or GNOME is chosen for oom kill on desktop systems instead of a memory hogging task. The baseline for the heuristic is a proportion of memory that each task is currently using in memory plus swap compared to the amount of "allowable" memory. "Allowable," in this sense, means the system-wide resources for unconstrained oom conditions, the set of mempolicy nodes, the mems attached to current's cpuset, or a memory controller's limit. The proportion is given on a scale of 0 (never kill) to 1000 (always kill), roughly meaning that if a task has a badness() score of 500 that the task consumes approximately 50% of allowable memory resident in RAM or in swap space. The proportion is always relative to the amount of "allowable" memory and not the total amount of RAM systemwide so that mempolicies and cpusets may operate in isolation; they shall not need to know the true size of the machine on which they are running if they are bound to a specific set of nodes or mems, respectively. Root tasks are given 3% extra memory just like __vm_enough_memory() provides in LSMs. In the event of two tasks consuming similar amounts of memory, it is generally better to save root's task. Because of the change in the badness() heuristic's baseline, it is also necessary to introduce a new user interface to tune it. It's not possible to redefine the meaning of /proc/pid/oom_adj with a new scale since the ABI cannot be changed for backward compatability. Instead, a new tunable, /proc/pid/oom_score_adj, is added that ranges from -1000 to +1000. It may be used to polarize the heuristic such that certain tasks are never considered for oom kill while others may always be considered. The value is added directly into the badness() score so a value of -500, for example, means to discount 50% of its memory consumption in comparison to other tasks either on the system, bound to the mempolicy, in the cpuset, or sharing the same memory controller. /proc/pid/oom_adj is changed so that its meaning is rescaled into the units used by /proc/pid/oom_score_adj, and vice versa. Changing one of these per-task tunables will rescale the value of the other to an equivalent meaning. Although /proc/pid/oom_adj was originally defined as a bitshift on the badness score, it now shares the same linear growth as /proc/pid/oom_score_adj but with different granularity. This is required so the ABI is not broken with userspace applications and allows oom_adj to be deprecated for future removal. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.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>
2010-08-09oom: move badness() declaration into oom.hAndrew Morton
Cc: Minchan Kim <minchan.kim@gmail.com> Cc: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09vmscan: kill prev_priority completelyKOSAKI Motohiro
Since 2.6.28 zone->prev_priority is unused. Then it can be removed safely. It reduce stack usage slightly. Now I have to say that I'm sorry. 2 years ago, I thought prev_priority can be integrate again, it's useful. but four (or more) times trying haven't got good performance number. Thus I give up such approach. The rest of this changelog is notes on prev_priority and why it existed in the first place and why it might be not necessary any more. This information is based heavily on discussions between Andrew Morton, Rik van Riel and Kosaki Motohiro who is heavily quotes from. Historically prev_priority was important because it determined when the VM would start unmapping PTE pages. i.e. there are no balances of note within the VM, Anon vs File and Mapped vs Unmapped. Without prev_priority, there is a potential risk of unnecessarily increasing minor faults as a large amount of read activity of use-once pages could push mapped pages to the end of the LRU and get unmapped. There is no proof this is still a problem but currently it is not considered to be. Active files are not deactivated if the active file list is smaller than the inactive list reducing the liklihood that file-mapped pages are being pushed off the LRU and referenced executable pages are kept on the active list to avoid them getting pushed out by read activity. Even if it is a problem, prev_priority prev_priority wouldn't works nowadays. First of all, current vmscan still a lot of UP centric code. it expose some weakness on some dozens CPUs machine. I think we need more and more improvement. The problem is, current vmscan mix up per-system-pressure, per-zone-pressure and per-task-pressure a bit. example, prev_priority try to boost priority to other concurrent priority. but if the another task have mempolicy restriction, it is unnecessary, but also makes wrong big latency and exceeding reclaim. per-task based priority + prev_priority adjustment make the emulation of per-system pressure. but it have two issue 1) too rough and brutal emulation 2) we need per-zone pressure, not per-system. Another example, currently DEF_PRIORITY is 12. it mean the lru rotate about 2 cycle (1/4096 + 1/2048 + 1/1024 + .. + 1) before invoking OOM-Killer. but if 10,0000 thrreads enter DEF_PRIORITY reclaim at the same time, the system have higher memory pressure than priority==0 (1/4096*10,000 > 2). prev_priority can't solve such multithreads workload issue. In other word, prev_priority concept assume the sysmtem don't have lots threads." Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michael Rubin <mrubin@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09mm: implement writeback livelock avoidance using page taggingJan Kara
We try to avoid livelocks of writeback when some steadily creates dirty pages in a mapping we are writing out. For memory-cleaning writeback, using nr_to_write works reasonably well but we cannot really use it for data integrity writeback. This patch tries to solve the problem. The idea is simple: Tag all pages that should be written back with a special tag (TOWRITE) in the radix tree. This can be done rather quickly and thus livelocks should not happen in practice. Then we start doing the hard work of locking pages and sending them to disk only for those pages that have TOWRITE tag set. Note: Adding new radix tree tag grows radix tree node from 288 to 296 bytes for 32-bit archs and from 552 to 560 bytes for 64-bit archs. However, the number of slab/slub items per page remains the same (13 and 7 respectively). Signed-off-by: Jan Kara <jack@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Chris Mason <chris.mason@oracle.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09radix-tree: omplement function radix_tree_range_tag_if_taggedJan Kara
Implement function for setting one tag if another tag is set for each item in given range. Signed-off-by: Jan Kara <jack@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Chris Mason <chris.mason@oracle.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09ksm: fix ksm swapin time optimizationAndrea Arcangeli
The new anon-vma code, was suboptimal and it lead to erratic invocation of ksm_does_need_to_copy. That leads to host hangs or guest vnc lockup, or weird behavior. It's unclear why ksm_does_need_to_copy is unstable but the point is that when KSM is not in use, ksm_does_need_to_copy must never run or we bounce pages for no good reason. I suspect the same hangs will happen with KVM swaps. But this at least fixes the regression in the new-anon-vma code and it only let KSM bugs triggers when KSM is in use. The code in do_swap_page likely doesn't cope well with a not-swapcache, especially the memcg code. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Rik van Riel <riel@redhat.com> Cc: Izik Eidus <ieidus@yahoo.com> Cc: Avi Kivity <avi@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09tmpfs: make tmpfs scalable with percpu_counter for used blocksTim Chen
The current implementation of tmpfs is not scalable. We found that stat_lock is contended by multiple threads when we need to get a new page, leading to useless spinning inside this spin lock. This patch makes use of the percpu_counter library to maintain local count of used blocks to speed up getting and returning of pages. So the acquisition of stat_lock is unnecessary for getting and returning blocks, improving the performance of tmpfs on system with large number of cpus. On a 4 socket 32 core NHM-EX system, we saw improvement of 270%. The implementation below has a slight chance of race between threads causing a slight overshoot of the maximum configured blocks. However, any overshoot is small, and is bounded by the number of cpus. This happens when the number of used blocks is slightly below the maximum configured blocks when a thread checks the used block count, and another thread allocates the last block before the current thread does. This should not be a problem for tmpfs, as the overshoot is most likely to be a few blocks and bounded. If a strict limit is really desired, then configured the max blocks to be the limit less the number of cpus in system. Signed-off-by: Tim Chen <tim.c.chen@linux.intel.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>
2010-08-09tmpfs: add accurate compare function to percpu_counter libraryTim Chen
Add percpu_counter_compare that allows for a quick but accurate comparison of percpu_counter with a given value. A rough count is provided by the count field in percpu_counter structure, without accounting for the other values stored in individual cpu counters. The actual count is a sum of count and the cpu counters. However, count field is never different from the actual value by a factor of batch*num_online_cpu. We do not need to get actual count for comparison if count is different from the given value by this factor and allows for quick comparison without summing up all the per cpu counters. Signed-off-by: Tim Chen <tim.c.chen@linux.intel.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>
2010-08-09gcc-4.6: mm: fix unused but set warningsAndi Kleen
No real bugs, just some dead code and some fixups. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09gcc-4.6: pagemap: avoid unused-but-set variableAndi Kleen
Avoid quite a lot of warnings in header files in a gcc 4.6 -Wall builds Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09topology: alternate fix for ia64 tiger_defconfig build breakageLee Schermerhorn
Define stubs for the numa_*_id() generic percpu related functions for non-NUMA configurations in <asm-generic/topology.h> where the other non-numa stubs live. Fixes ia64 !NUMA build breakage -- e.g., tiger_defconfig Back out now unneeded '#ifndef CONFIG_NUMA' guards from ia64 smpboot.c Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Tested-by: Tony Luck <tony.luck@intel.com> Acked-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09mmzone.h: remove dead prototypeAlexander Nevenchannyy
get_zone_counts() was dropped from kernel tree, see: http://www.mail-archive.com/mm-commits@vger.kernel.org/msg07313.html but its prototype remains. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09mm: rename try_set_zone_oom() to try_set_zonelist_oom()Minchan Kim
We have been used naming try_set_zone_oom and clear_zonelist_oom. The role of functions is to lock of zonelist for preventing parallel OOM. So clear_zonelist_oom makes sense but try_set_zone_oome is rather awkward and unmatched with clear_zonelist_oom. Let's change it with try_set_zonelist_oom. Signed-off-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: David Rientjes <rientjes@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.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>
2010-08-09oom: move sysctl declarations to oom.hDavid Rientjes
The three oom killer sysctl variables (sysctl_oom_dump_tasks, sysctl_oom_kill_allocating_task, and sysctl_panic_on_oom) are better declared in include/linux/oom.h rather than kernel/sysctl.c. Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.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>
2010-08-09oom: extract panic helper functionDavid Rientjes
There are various points in the oom killer where the kernel must determine whether to panic or not. It's better to extract this to a helper function to remove all the confusion as to its semantics. Also fix a call to dump_header() where tasklist_lock is not read- locked, as required. There's no functional change with this patch. Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: David Rientjes <rientjes@google.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>
2010-08-09oom: select task from tasklist for mempolicy oomsDavid Rientjes
The oom killer presently kills current whenever there is no more memory free or reclaimable on its mempolicy's nodes. There is no guarantee that current is a memory-hogging task or that killing it will free any substantial amount of memory, however. In such situations, it is better to scan the tasklist for nodes that are allowed to allocate on current's set of nodes and kill the task with the highest badness() score. This ensures that the most memory-hogging task, or the one configured by the user with /proc/pid/oom_adj, is always selected in such scenarios. Signed-off-by: David Rientjes <rientjes@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.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>
2010-08-09buffer_head: remove redundant test from wait_on_bufferRichard Kennedy
The comment suggests that when b_count equals zero it is calling __wait_no_buffer to trigger some debug, but as there is no debug in __wait_on_buffer the whole thing is redundant. AFAICT from the git log this has been the case for at least 5 years, so it seems safe just to remove this. Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09mm: extend KSM refcounts to the anon_vma rootRik van Riel
KSM reference counts can cause an anon_vma to exist after the processe it belongs to have already exited. Because the anon_vma lock now lives in the root anon_vma, we need to ensure that the root anon_vma stays around until after all the "child" anon_vmas have been freed. The obvious way to do this is to have a "child" anon_vma take a reference to the root in anon_vma_fork. When the anon_vma is freed at munmap or process exit, we drop the refcount in anon_vma_unlink and possibly free the root anon_vma. The KSM anon_vma reference count function also needs to be modified to deal with the possibility of freeing 2 levels of anon_vma. The easiest way to do this is to break out the KSM magic and make it generic. When compiling without CONFIG_KSM, this code is compiled out. Signed-off-by: Rik van Riel <riel@redhat.com> Tested-by: Larry Woodman <lwoodman@redhat.com> Acked-by: Larry Woodman <lwoodman@redhat.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Tested-by: Dave Young <hidave.darkstar@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09mm: always lock the root (oldest) anon_vmaRik van Riel
Always (and only) lock the root (oldest) anon_vma whenever we do something in an anon_vma. The recently introduced anon_vma scalability is due to the rmap code scanning only the VMAs that need to be scanned. Many common operations still took the anon_vma lock on the root anon_vma, so always taking that lock is not expected to introduce any scalability issues. However, always taking the same lock does mean we only need to take one lock, which means rmap_walk on pages from any anon_vma in the vma is excluded from occurring during an munmap, expand_stack or other operation that needs to exclude rmap_walk and similar functions. Also add the proper locking to vma_adjust. Signed-off-by: Rik van Riel <riel@redhat.com> Tested-by: Larry Woodman <lwoodman@redhat.com> Acked-by: Larry Woodman <lwoodman@redhat.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09mm: track the root (oldest) anon_vmaRik van Riel
Track the root (oldest) anon_vma in each anon_vma tree. Because we only take the lock on the root anon_vma, we cannot use the lock on higher-up anon_vmas to lock anything. This makes it impossible to do an indirect lookup of the root anon_vma, since the data structures could go away from under us. However, a direct pointer is safe because the root anon_vma is always the last one that gets freed on munmap or exit, by virtue of the same_vma list order and unlink_anon_vmas walking the list forward. [akpm@linux-foundation.org: fix typo] Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Larry Woodman <lwoodman@redhat.com> Acked-by: Larry Woodman <lwoodman@redhat.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09mm: change direct call of spin_lock(anon_vma->lock) to inline functionRik van Riel
Subsitute a direct call of spin_lock(anon_vma->lock) with an inline function doing exactly the same. This makes it easier to do the substitution to the root anon_vma lock in a following patch. We will deal with the handful of special locks (nested, dec_and_lock, etc) separately. Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Larry Woodman <lwoodman@redhat.com> Acked-by: Larry Woodman <lwoodman@redhat.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09mm: rename anon_vma_lock to vma_lock_anon_vmaRik van Riel
Rename anon_vma_lock to vma_lock_anon_vma. This matches the naming style used in page_lock_anon_vma and will come in really handy further down in this patch series. Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Larry Woodman <lwoodman@redhat.com> Acked-by: Larry Woodman <lwoodman@redhat.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09kmap_atomic: make kunmap_atomic() harder to misuseCesar Eduardo Barros
kunmap_atomic() is currently at level -4 on Rusty's "Hard To Misuse" list[1] ("Follow common convention and you'll get it wrong"), except in some architectures when CONFIG_DEBUG_HIGHMEM is set[2][3]. kunmap() takes a pointer to a struct page; kunmap_atomic(), however, takes takes a pointer to within the page itself. This seems to once in a while trip people up (the convention they are following is the one from kunmap()). Make it much harder to misuse, by moving it to level 9 on Rusty's list[4] ("The compiler/linker won't let you get it wrong"). This is done by refusing to build if the type of its first argument is a pointer to a struct page. The real kunmap_atomic() is renamed to kunmap_atomic_notypecheck() (which is what you would call in case for some strange reason calling it with a pointer to a struct page is not incorrect in your code). The previous version of this patch was compile tested on x86-64. [1] http://ozlabs.org/~rusty/index.cgi/tech/2008-04-01.html [2] In these cases, it is at level 5, "Do it right or it will always break at runtime." [3] At least mips and powerpc look very similar, and sparc also seems to share a common ancestor with both; there seems to be quite some degree of copy-and-paste coding here. The include/asm/highmem.h file for these three archs mention x86 CPUs at its top. [4] http://ozlabs.org/~rusty/index.cgi/tech/2008-03-30.html [5] As an aside, could someone tell me why mn10300 uses unsigned long as the first parameter of kunmap_atomic() instead of void *? Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Cc: Russell King <linux@arm.linux.org.uk> (arch/arm) Cc: Ralf Baechle <ralf@linux-mips.org> (arch/mips) Cc: David Howells <dhowells@redhat.com> (arch/frv, arch/mn10300) Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> (arch/mn10300) Cc: Kyle McMartin <kyle@mcmartin.ca> (arch/parisc) Cc: Helge Deller <deller@gmx.de> (arch/parisc) Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> (arch/parisc) Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> (arch/powerpc) Cc: Paul Mackerras <paulus@samba.org> (arch/powerpc) Cc: "David S. Miller" <davem@davemloft.net> (arch/sparc) Cc: Thomas Gleixner <tglx@linutronix.de> (arch/x86) Cc: Ingo Molnar <mingo@redhat.com> (arch/x86) Cc: "H. Peter Anvin" <hpa@zytor.com> (arch/x86) Cc: Arnd Bergmann <arnd@arndb.de> (include/asm-generic) Cc: Rusty Russell <rusty@rustcorp.com.au> ("Hard To Misuse" list) Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09Fix sget() race with failing mountAl Viro
If sget() finds a matching superblock being set up, it'll grab an active reference to it and grab s_umount. That's fine - we'll wait for completion of foofs_get_sb() that way. However, if said foofs_get_sb() fails we'll end up holding the halfway-created superblock. deactivate_locked_super() called by foofs_get_sb() will just unlock the sucker since we are holding another active reference to it. What we need is a way to tell if superblock has been successfully set up. Unfortunately, neither ->s_root nor the check for MS_ACTIVE quite fit. Cheap and easy way, suitable for backport: new flag set by the (only) caller of ->get_sb(). If that flag isn't present by the time sget() grabbed s_umount on preexisting superblock it has found, it's seeing a stillborn and should just bury it with deactivate_locked_super() (and repeat the search). Longer term we want to set that flag in ->get_sb() instances (and check for it to distinguish between "sget() found us a live sb" and "sget() has allocated an sb, we need to set it up" in there, instead of checking ->s_root as we do now). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Cc: stable@kernel.org
2010-08-09mbcache: Remove unused featuresAndreas Gruenbacher
The mbcache code was written to support a variable number of indexes, but all the existing users use exactly one index. Simplify to code to support only that case. There are also no users of the cache entry free operation, and none of the users keep extra data in cache entries. Remove those features as well. Signed-off-by: Andreas Gruenbacher <agruen@suse.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09add f_flags to struct statfs(64)Christoph Hellwig
Add a flags field to help glibc implementing statvfs(3) efficiently. We copy the flag values from glibc, and add a new ST_VALID flag to denote that f_flags is implemented. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09pass a struct path to vfs_statfsChristoph Hellwig
We'll need the path to implement the flags field for statvfs support. We do have it available in all callers except: - ecryptfs_statfs. This one doesn't actually need vfs_statfs but just needs to do a caller to the lower filesystem statfs method. - sys_ustat. Add a non-exported statfs_by_dentry helper for it which doesn't won't be able to fill out the flags field later on. In addition rename the helpers for statfs vs fstatfs to do_*statfs instead of the misleading vfs prefix. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09convert remaining ->clear_inode() to ->evict_inode()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09Make ->drop_inode() just return whether inode needs to be droppedAl Viro
... and let iput_final() do the actual eviction or retention Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09fs/inode.c:clear_inode() is goneAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09->delete_inode() is goneAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09convert reiserfs to ->evict_inode()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09new helper: __dentry_path()Al Viro
builds path relative to fs root, called under dcache_lock, doesn't append any nonsense to unlinked ones. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09convert ext3 to ->evict_inode()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>