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* kexec: fix Oops in crash_shrink_memory()Pavan Naregundi2010-06-291-3/+4
| | | | | | | | | | | | | | | | | | | When crashkernel is not enabled, "echo 0 > /sys/kernel/kexec_crash_size" OOPSes the kernel in crash_shrink_memory. This happens when crash_shrink_memory tries to release the 'crashk_res' resource which are not reserved. Also value of "/sys/kernel/kexec_crash_size" shows as 1, which should be 0. This patch fixes the OOPS in crash_shrink_memory and shows "/sys/kernel/kexec_crash_size" as 0 when crash kernel memory is not reserved. Signed-off-by: Pavan Naregundi <pavan@linux.vnet.ibm.com> Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com> Cc: Simon Horman <horms@verge.net.au> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* MAINTAINERS: update files and add maintainer for SAMSUNG ARM ARCHITECTURESKukjin Kim2010-06-291-1/+3
| | | | | | | | Signed-off-by: Kukjin Kim <kgene.kim@samsung.com> Acked-by: Ben Dooks <ben-linux@fluff.org> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* compiler-gcc.h: gcc-4.5 needs noclone and noinline on __naked functionsMikael Pettersson2010-06-292-1/+13
| | | | | | | | | | | | | | | | | | | | | A __naked function is defined in C but with a body completely implemented by asm(), including any prologue and epilogue. These asm() bodies expect standard calling conventions for parameter passing. Older GCCs implement that correctly, but 4.[56] currently do not, see GCC PR44290. In the Linux kernel this breaks ARM, causing most arch/arm/mm/copypage-*.c modules to get miscompiled, resulting in kernel crashes during bootup. Part of the kernel fix is to augment the __naked function attribute to also imply noinline and noclone. This patch implements that, and has been verified to fix boot failures with gcc-4.5 compiled 2.6.34 and 2.6.35-rc1 kernels. The patch is a no-op with older GCCs. Signed-off-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Khem Raj <raj.khem@gmail.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* flat: tweak default stack alignmentMike Frysinger2010-06-291-5/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The recent commit 1f0ce8b3dd667dca7 ("mm: Move ARCH_SLAB_MINALIGN and ARCH_KMALLOC_MINALIGN to <linux/slab_def.h>") which moved the ARCH_SLAB_MINALIGN default into the global header inadvertently broke FLAT for a bunch of systems. Blackfin systems now fail on any FLAT exec with: Unable to read code+data+bss, errno 14 When your /init is a FLAT binary, obviously this can be annoying ;). This stems from the alignment usage in the FLAT loader. The behavior before was that FLAT would default to ARCH_SLAB_MINALIGN only if it was defined, and this was only defined by arches when they wanted a larger alignment value. Otherwise it'd default to pointer alignment. Arguably, this is kind of hokey that the FLAT is semi-abusing defines it shouldn't. So let's merge the two alignment requirements so the floor is never 0. Signed-off-by: Mike Frysinger <vapier@gentoo.org> Cc: David McCullough <davidm@snapgear.com> Cc: Greg Ungerer <gerg@uclinux.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Michal Simek <monstr@monstr.eu> Cc: Hirokazu Takata <takata@linux-m32r.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: David Howells <dhowells@redhat.com> Cc: David Woodhouse <David.Woodhouse@intel.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lxfb: fix incorrect __init annotationAndres Salomon2010-06-291-8/+10
| | | | | | | | | | | | | | WARNING: vmlinux.o(.data+0x196e8): Section mismatch in reference from the variable lxfb_driver to the function .init.text:lxfb_probe() The variable lxfb_driver references the function __init lxfb_probe() This changes lxfb_probe and friends to use __devinit, and also adds __devexit to lxfb_remove. Signed-off-by: Andres Salomon <dilinger@queued.net> Cc: Jordan Crouse <jordan.crouse@amd.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* gxfb: fix incorrect __init annotationAndres Salomon2010-06-291-8/+12
| | | | | | | | | | | | | | WARNING: vmlinux.o(.data+0x195d8): Section mismatch in reference from the variable gxfb_driver to the function .init.text:gxfb_probe() The variable gxfb_driver references the function __init gxfb_probe() This changes gxfb_probe and friends to use __devinit, and also adds __devexit to gxfb_remove. Signed-off-by: Andres Salomon <dilinger@queued.net> Cc: Jordan Crouse <jordan.crouse@amd.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: fix wake up in oom wait queueKAMEZAWA Hiroyuki2010-06-291-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | OOM-waitqueue should be waken up when oom_disable is canceled. This is a fix for 3c11ecf448eff8f1 ("memcg: oom kill disable and oom status"). How to test: Create a cgroup A... 1. set memory.limit and memory.memsw.limit to be small value 2. echo 1 > /cgroup/A/memory.oom_control, this disables oom-kill. 3. run a program which must cause OOM. A program executed in 3 will sleep by oom_waiqueue in memcg. Then, how to wake it up is problem. 1. echo 0 > /cgroup/A/memory.oom_control (enable OOM-killer) 2. echo big mem > /cgroup/A/memory.memsw.limit_in_bytes(allow more swap) etc.. Without the patch, a task in slept can not be waken up. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* nommu: add '[stack]' label to /proc/pid/maps outputMike Frysinger2010-06-291-4/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add support to the NOMMU /proc/pid/maps file to show which mapping is the stack of the original thread after execve. This is largely based on the MMU code. Subsidiary thread stacks are not indicated. For FDPIC, we now get: root:/> cat /proc/self/maps 02064000-02067ccc rw-p 0004d000 00:01 22 /bin/busybox 0206e000-0206f35c rw-p 00006000 00:01 295 /lib/ld-uClibc.so.0 025f0000-025f6f0c r-xs 00000000 00:01 295 /lib/ld-uClibc.so.0 02680000-026ba6b0 r-xs 00000000 00:01 297 /lib/libc.so.0 02700000-0274d384 r-xs 00000000 00:01 22 /bin/busybox 02816000-02817000 rw-p 00000000 00:00 0 02848000-0284c0d8 rw-p 00000000 00:00 0 02860000-02880000 rw-p 00000000 00:00 0 [stack] The semi-downside here is that for FLAT, we get: root:/> cat /proc/155/maps 029f0000-029f9000 rwxp 00000000 00:00 0 [stack] The reason being that FLAT combines a whole lot of stuff into one map (including the stack). But this isn't any worse than the current output (which is nothing), so screw it. Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: David Howells <dhowells@redhat.com> Cc: Greg Ungerer <gerg@snapgear.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* genalloc: fix allocation from end of poolImre Deak2010-06-291-1/+0
| | | | | | | | | | | | | | | | bitmap_find_next_zero_area requires the size of the bitmap, we instead passed the last suitable position. This made it impossible to allocate from the end of the pool. Fixes a regression introduced by 243797f59b748f679ab88d456fcc4f92236d724b ("genalloc: use bitmap_find_next_zero_area"). Signed-off-by: Imre Deak <imre.deak@nokia.com> Cc: Zygo Blaxell <zygo.blaxell@xandros.com> Cc: Tejun Heo <tj@kernel.org> Acked-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds2010-06-2912-193/+280
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of git://git.kernel.dk/linux-2.6-block: block: Don't count_vm_events for discard bio in submit_bio. cfq: fix recursive call in cfq_blkiocg_update_completion_stats() cfq-iosched: Fixed boot warning with BLK_CGROUP=y and CFQ_GROUP_IOSCHED=n cfq: Don't allow queue merges for queues that have no process references block: fix DISCARD_BARRIER requests cciss: set SCSI max cmd len to 16, as default is wrong cpqarray: fix two more wrong section type cpqarray: fix wrong __init type on pci probe function drbd: Fixed a race between disk-attach and unexpected state changes writeback: fix pin_sb_for_writeback writeback: add missing requeue_io in writeback_inodes_wb writeback: simplify and split bdi_start_writeback writeback: simplify wakeup_flusher_threads writeback: fix writeback_inodes_wb from writeback_inodes_sb writeback: enforce s_umount locking in writeback_inodes_sb writeback: queue work on stack in writeback_inodes_sb writeback: fix writeback completion notifications
| * block: Don't count_vm_events for discard bio in submit_bio.Tao Ma2010-06-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | In submit_bio, we count vm events by check READ/WRITE. But actually DISCARD_NOBARRIER also has the WRITE flag set. It looks as if in blkdev_issue_discard, we also add a page as the payload and the bio_has_data check isn't enough. So add another check for discard bio. Signed-off-by: Tao Ma <tao.ma@oracle.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
| * cfq: fix recursive call in cfq_blkiocg_update_completion_stats()Jens Axboe2010-06-211-1/+1
| | | | | | | | | | | | | | | | e98ef89b has a typo, causing cfq_blkiocg_update_completion_stats() to call itself instead of blkiocg_update_completion_stats(). Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
| * cfq-iosched: Fixed boot warning with BLK_CGROUP=y and CFQ_GROUP_IOSCHED=nVivek Goyal2010-06-182-27/+142
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Hi Jens, Few days back Ingo noticed a CFQ boot time warning. This patch fixes it. The issue here is that with CFQ_GROUP_IOSCHED=n, CFQ should not really be making blkio stat related calls. > Hm, it's still not entirely fixed, as of 2.6.35-rc2-00131-g7908a9e. With > some > configs i get bad spinlock warnings during bootup: > > [ 28.968013] initcall net_olddevs_init+0x0/0x82 returned 0 after 93750 > usecs > [ 28.972003] calling b44_init+0x0/0x55 @ 1 > [ 28.976009] bus: 'pci': add driver b44 > [ 28.976374] sda: > [ 28.978157] BUG: spinlock bad magic on CPU#1, async/0/117 > [ 28.980000] lock: 7e1c5bbc, .magic: 00000000, .owner: <none>/-1, +.owner_cpu: 0 > [ 28.980000] Pid: 117, comm: async/0 Not tainted +2.6.35-rc2-tip-01092-g010e7ef-dirty #8183 > [ 28.980000] Call Trace: > [ 28.980000] [<41ba6d55>] ? printk+0x20/0x24 > [ 28.980000] [<4134b7b7>] spin_bug+0x7c/0x87 > [ 28.980000] [<4134b853>] do_raw_spin_lock+0x1e/0x123 > [ 28.980000] [<41ba92ca>] ? _raw_spin_lock_irqsave+0x12/0x20 > [ 28.980000] [<41ba92d2>] _raw_spin_lock_irqsave+0x1a/0x20 > [ 28.980000] [<4133476f>] blkiocg_update_io_add_stats+0x25/0xfb > [ 28.980000] [<41335dae>] ? cfq_prio_tree_add+0xb1/0xc1 > [ 28.980000] [<41337bc7>] cfq_insert_request+0x8c/0x425 Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
| * cfq: Don't allow queue merges for queues that have no process referencesJeff Moyer2010-06-171-2/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Hi, A user reported a kernel bug when running a particular program that did the following: created 32 threads - each thread took a mutex, grabbed a global offset, added a buffer size to that offset, released the lock - read from the given offset in the file - created a new thread to do the same - exited The result is that cfq's close cooperator logic would trigger, as the threads were issuing I/O within the mean seek distance of one another. This workload managed to routinely trigger a use after free bug when walking the list of merge candidates for a particular cfqq (cfqq->new_cfqq). The logic used for merging queues looks like this: static void cfq_setup_merge(struct cfq_queue *cfqq, struct cfq_queue *new_cfqq) { int process_refs, new_process_refs; struct cfq_queue *__cfqq; /* Avoid a circular list and skip interim queue merges */ while ((__cfqq = new_cfqq->new_cfqq)) { if (__cfqq == cfqq) return; new_cfqq = __cfqq; } process_refs = cfqq_process_refs(cfqq); /* * If the process for the cfqq has gone away, there is no * sense in merging the queues. */ if (process_refs == 0) return; /* * Merge in the direction of the lesser amount of work. */ new_process_refs = cfqq_process_refs(new_cfqq); if (new_process_refs >= process_refs) { cfqq->new_cfqq = new_cfqq; atomic_add(process_refs, &new_cfqq->ref); } else { new_cfqq->new_cfqq = cfqq; atomic_add(new_process_refs, &cfqq->ref); } } When a merge candidate is found, we add the process references for the queue with less references to the queue with more. The actual merging of queues happens when a new request is issued for a given cfqq. In the case of the test program, it only does a single pread call to read in 1MB, so the actual merge never happens. Normally, this is fine, as when the queue exits, we simply drop the references we took on the other cfqqs in the merge chain: /* * If this queue was scheduled to merge with another queue, be * sure to drop the reference taken on that queue (and others in * the merge chain). See cfq_setup_merge and cfq_merge_cfqqs. */ __cfqq = cfqq->new_cfqq; while (__cfqq) { if (__cfqq == cfqq) { WARN(1, "cfqq->new_cfqq loop detected\n"); break; } next = __cfqq->new_cfqq; cfq_put_queue(__cfqq); __cfqq = next; } However, there is a hole in this logic. Consider the following (and keep in mind that each I/O keeps a reference to the cfqq): q1->new_cfqq = q2 // q2 now has 2 process references q3->new_cfqq = q2 // q2 now has 3 process references // the process associated with q2 exits // q2 now has 2 process references // queue 1 exits, drops its reference on q2 // q2 now has 1 process reference // q3 exits, so has 0 process references, and hence drops its references // to q2, which leaves q2 also with 0 process references q4 comes along and wants to merge with q3 q3->new_cfqq still points at q2! We follow that link and end up at an already freed cfqq. So, the fix is to not follow a merge chain if the top-most queue does not have a process reference, otherwise any queue in the chain could be already freed. I also changed the logic to disallow merging with a queue that does not have any process references. Previously, we did this check for one of the merge candidates, but not the other. That doesn't really make sense. Without the attached patch, my system would BUG within a couple of seconds of running the reproducer program. With the patch applied, my system ran the program for over an hour without issues. This addresses the following bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=16217 Thanks a ton to Phil Carns for providing the bug report and an excellent reproducer. [ Note for stable: this applies to 2.6.32/33/34 ]. Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Reported-by: Phil Carns <carns@mcs.anl.gov> Cc: stable@kernel.org Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
| * block: fix DISCARD_BARRIER requestsChristoph Hellwig2010-06-171-5/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | Filesystems assume that DISCARD_BARRIER are full barriers, so that they don't have to track in-progress discard operation when submitting new I/O. But currently we only treat them as elevator barriers, which don't actually do the nessecary queue drains. Also remove the unlikely around both the DISCARD and BARRIER requests - the happen far too often for a static mispredict. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
| * cciss: set SCSI max cmd len to 16, as default is wrongStephen M. Cameron2010-06-151-0/+1
| | | | | | | | | | | | | | Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com> Cc: Mike Miller <mikem@beardog.cce.hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
| * cpqarray: fix two more wrong section typeJens Axboe2010-06-141-2/+2
| | | | | | | | | | | | | | cpqarray_register_ctlr() and cpqarray_eisa_detect() also need to be marked as __devinit. Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
| * cpqarray: fix wrong __init type on pci probe functionJens Axboe2010-06-141-1/+1
| | | | | | | | | | | | It needs to be __devinit, not __init. Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
| * Merge branch 'for-jens' of git://git.drbd.org/linux-2.6-drbd into for-linusJens Axboe2010-06-1450-243/+290
| |\
| | * drbd: Fixed a race between disk-attach and unexpected state changesPhilipp Reisner2010-06-143-3/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This was a very hard to trigger race condition. If we got a state packet from the peer, after drbd_nl_disk() has already changed the disk state to D_NEGOTIATING but after_state_ch() was not yet run by the worker, then receive_state() might called drbd_sync_handshake(), which in turn crashed when accessing p_uuid. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
| * | writeback: fix pin_sb_for_writebackChristoph Hellwig2010-06-111-8/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We need to check for s_instances to make sure we don't bother working against a filesystem that is beeing unmounted, and we need to call put_super to make sure a superblock is freed when we race against umount. Also no need to keep sb_lock after we got a reference on it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
| * | writeback: add missing requeue_io in writeback_inodes_wbChristoph Hellwig2010-06-111-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In "writeback: fix writeback_inodes_wb from writeback_inodes_sb" I accidentally removed the requeue_io if we need to skip a superblock because we can't pin it. Add it back, otherwise we're getting spurious lockups after multiple xfstests runs. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
| * | writeback: simplify and split bdi_start_writebackChristoph Hellwig2010-06-113-17/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | bdi_start_writeback now never gets a superblock passed, so we can just remove that case. And to further untangle the code and flatten the call stack split it into two trivial helpers for it's two callers. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
| * | writeback: simplify wakeup_flusher_threadsChristoph Hellwig2010-06-111-21/+11
| | | | | | | | | | | | | | | | | | | | | | | | bdi_writeback_all only has one caller, so fold it to simplify the code and flatten the call stack. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
| * | writeback: fix writeback_inodes_wb from writeback_inodes_sbChristoph Hellwig2010-06-111-38/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we call writeback_inodes_wb from writeback_inodes_sb we always have s_umount held, which currently makes the whole operation a no-op. But if we are called to write out inodes for a specific superblock we always have s_umount held, so replace the incorrect logic checking for WB_SYNC_ALL which only worked by coincidence with the proper check for an explicit superblock argument. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
| * | writeback: enforce s_umount locking in writeback_inodes_sbChristoph Hellwig2010-06-112-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make sure that not only sync_filesystem but all callers of writeback_inodes_sb have the superblock protected against remount. As-is this disables all functionality for these callers, but the next patch relies on this locking to fix writeback_inodes_sb for sync_filesystem. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
| * | writeback: queue work on stack in writeback_inodes_sbChristoph Hellwig2010-06-111-19/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we want to rely on s_umount in the caller we need to wait for completion of the I/O submission before returning to the caller. Refactor bdi_sync_writeback into a bdi_queue_work_onstack helper and use it for this case. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
| * | writeback: fix writeback completion notificationsChristoph Hellwig2010-06-111-50/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The code dealing with bdi_work->state and completion of a bdi_work is a major mess currently. This patch makes sure we directly use one set of flags to deal with it, and use it consistently, which means: - always notify about completion from the rcu callback. We only ever wait for it from on-stack callers, so this simplification does not even cause a theoretical slowdown currently. It also makes sure we don't miss out on the notification if we ever add other callers to wait for it. - make earlier completion notification depending on the on-stack allocation, not the sync mode. If we introduce new callers that want to do WB_SYNC_NONE writeback from on-stack callers this will be nessecary. Also rename bdi_wait_on_work_clear to bdi_wait_on_work_done and inline a few small functions into their only caller to make the code understandable. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* | | fs: fix superblock iteration racenpiggin@suse.de2010-06-293-0/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | list_for_each_entry_safe is not suitable to protect against concurrent modification of the list. 6754af6 introduced a race in sb walking. list_for_each_entry can use the trick of pinning the current entry in the list before we drop and retake the lock because it subsequently follows cur->next. However list_for_each_entry_safe saves n=cur->next for following before entering the loop body, so when the lock is dropped, n may be deleted. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Christoph Hellwig <hch@infradead.org> Cc: John Stultz <johnstul@us.ibm.com> Cc: Frank Mayhar <fmayhar@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds2010-06-289-6/+39
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: tracing: Fix undeclared ENOSYS in include/linux/tracepoint.h perf record: prevent kill(0, SIGTERM); perf session: Remove threads from tree on PERF_RECORD_EXIT perf/tracing: Fix regression of perf losing kprobe events perf_events: Fix Intel Westmere event constraints perf record: Don't call newt functions when not initialized
| * | | tracing: Fix undeclared ENOSYS in include/linux/tracepoint.hWu Zhangjin2010-06-211-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The header file include/linux/tracepoint.h may be included without include/linux/errno.h and then the compiler will fail on building for undelcared ENOSYS. This patch fixes this problem via including <linux/errno.h> to include/linux/tracepoint.h. Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com> LKML-Reference: <1277118549-622-1-git-send-email-wuzhangjin@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | perf record: prevent kill(0, SIGTERM);Ian Munsie2010-06-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | At exit, perf record will kill the process it was profiling by sending a SIGTERM to child_pid (if it had been initialised), but in certain situations child_pid may be 0 and perf would mistakenly kill more processes than intended. child_pid is set to the return of fork() to either 0 or the pid of the child. Ordinarily this would not present an issue as the child calls execvp to spawn the process to be profiled and would therefore never run it's sig_atexit and never attempt to kill pid 0. However, if a nonexistant binary had been passed in to perf record the call to execvp would fail and child_pid would be left set to 0. The child would then exit and it's atexit handler, finding that child_pid was initialised to 0, would call kill(0, SIGTERM), resulting in every process within it's process group being killed. In the case that perf was being run directly from the shell this typically would not be an issue as the shell isolates the process. However, if perf was being called from another program it could kill unexpected processes, which may even include X. This patch changes the logic of the test for whether child_pid was initialised to only consider positive pids as valid, thereby never attempting to kill pid 0. Cc: David S. Miller <davem@davemloft.net> Cc: Frédéric Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tom Zanussi <tzanussi@gmail.com> LKML-Reference: <1276072680-17378-1-git-send-email-imunsie@au1.ibm.com> Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * | | perf session: Remove threads from tree on PERF_RECORD_EXITArnaldo Carvalho de Melo2010-06-174-2/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move them to a session->dead_threads list just like we do with maps that are replaced, because we may have hist_entries pointing to them. This fixes a bug when inserting maps for a new thread that reused the TID, mixing maps for two different threads, causing an endless loop. The code for insering maps should be made more robust but for .35 this is the minimalistic patch. Reported-by: Ingo Molnar <mingo@elte.hu> Cc: David S. Miller <davem@davemloft.net> Cc: Frédéric Weisbecker <fweisbec@gmail.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Tom Zanussi <tzanussi@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * | | Merge branch 'tip/perf/urgent' of ↵Ingo Molnar2010-06-111-1/+3
| |\ \ \ | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/urgent
| | * | | perf/tracing: Fix regression of perf losing kprobe eventsSteven Rostedt2010-06-101-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the addition of the code to shrink the kernel tracepoint infrastructure, we lost kprobes being traced by perf. The reason is that I tested if the "tp_event->class->perf_probe" existed before enabling it. This prevents "ftrace only" events (like the function trace events) from being enabled by perf. Unfortunately, kprobe events do not use perf_probe. This causes kprobes to be missed by perf. To fix this, we add the test to see if "tp_event->class->reg" exists as well as perf_probe. Normal trace events have only "perf_probe" but no "reg" function, and kprobes and syscalls have the "reg" but no "perf_probe". The ftrace unique events do not have either, so this is a valid test. If a kprobe or syscall is not to be probed by perf, the "reg" function is called anyway, and will return a failure and prevent perf from probing it. Reported-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | | perf record: Don't call newt functions when not initializedArnaldo Carvalho de Melo2010-06-101-2/+13
| |/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When processing events we want to give visual feedback to the user when using the newt browser, so there are ui_progress calls in __perf_session__process_events, but those should check if newt is being used. Reported-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Frédéric Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>, Cc: Peter Zijlstra <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Stephane Eranian <eranian@google.com> Cc: Tom Zanussi <tzanussi@gmail.com> LKML-Reference: <20100609123530.GB9471@ghostprotocols.net> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * | | perf_events: Fix Intel Westmere event constraintsStephane Eranian2010-06-101-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on Intel Vol3b (March 2010), the event SNOOPQ_REQUEST_OUTSTANDING is restricted to counters 0,1 so update the event table for Intel Westmere accordingly. Signed-off-by: Stephane Eranian <eranian@google.com> Cc: peterz@infradead.org Cc: paulus@samba.org Cc: davem@davemloft.net Cc: fweisbec@gmail.com Cc: perfmon2-devel@lists.sf.net Cc: eranian@gmail.com Cc: <stable@kernel.org> # .34.x LKML-Reference: <4c10cb56.5120e30a.2eb4.ffffc3de@mx.google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | Merge branch 'irq-fixes-for-linus' of ↵Linus Torvalds2010-06-281-0/+3
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: genirq: Deal with desc->set_type() changing desc->chip
| * | | | genirq: Deal with desc->set_type() changing desc->chipThomas Gleixner2010-06-091-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The set_type() function can change the chip implementation when the trigger mode changes. That might result in using an non-initialized irq chip when called from __setup_irq() or when called via set_irq_type() on an already enabled irq. The set_irq_type() function should not be called on an enabled irq, but because we forgot to put a check into it, we have a bunch of users which grew the habit of doing that and it never blew up as the function is serialized via desc->lock against all users of desc->chip and they never hit the non-initialized irq chip issue. The easy fix for the __setup_irq() issue would be to move the irq_chip_set_defaults(desc->chip) call after the trigger setting to make sure that a chip change is covered. But as we have already users, which do the type setting after request_irq(), the safe fix for now is to call irq_chip_set_defaults() from __irq_set_trigger() when desc->set_type() changed the irq chip. It needs a deeper analysis whether we should refuse to change the chip on an already enabled irq, but that'd be a large scale change to fix all the existing users. So that's neither stable nor 2.6.35 material. Reported-by: Esben Haabendal <eha@doredevelopment.dk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: linuxppc-dev <linuxppc-dev@ozlabs.org> Cc: stable@kernel.org
* | | | | Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds2010-06-282-65/+79
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: Prevent compiler from optimising the sched_avg_update() loop sched: Fix over-scheduling bug sched: Fix PROVE_RCU vs cpu_cgroup
| * | | | | sched: Prevent compiler from optimising the sched_avg_update() loopWill Deacon2010-06-251-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | GCC 4.4.1 on ARM has been observed to replace the while loop in sched_avg_update with a call to uldivmod, resulting in the following build failure at link-time: kernel/built-in.o: In function `sched_avg_update': kernel/sched.c:1261: undefined reference to `__aeabi_uldivmod' kernel/sched.c:1261: undefined reference to `__aeabi_uldivmod' make: *** [.tmp_vmlinux1] Error 1 This patch introduces a fake data hazard to the loop body to prevent the compiler optimising the loop away. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | sched: Fix over-scheduling bugAlex,Shi2010-06-181-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit e70971591 ("sched: Optimize unused cgroup configuration") introduced an imbalanced scheduling bug. If we do not use CGROUP, function update_h_load won't update h_load. When the system has a large number of tasks far more than logical CPU number, the incorrect cfs_rq[cpu]->h_load value will cause load_balance() to pull too many tasks to the local CPU from the busiest CPU. So the busiest CPU keeps going in a round robin. That will hurt performance. The issue was found originally by a scientific calculation workload that developed by Yanmin. With that commit, the workload performance drops about 40%. CPU before after 00 : 2 : 7 01 : 1 : 7 02 : 11 : 6 03 : 12 : 7 04 : 6 : 6 05 : 11 : 7 06 : 10 : 6 07 : 12 : 7 08 : 11 : 6 09 : 12 : 6 10 : 1 : 6 11 : 1 : 6 12 : 6 : 6 13 : 2 : 6 14 : 2 : 6 15 : 1 : 6 Reviewed-by: Yanmin zhang <yanmin.zhang@intel.com> Signed-off-by: Alex Shi <alex.shi@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1276754893.9452.5442.camel@debian> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | sched: Fix PROVE_RCU vs cpu_cgroupPeter Zijlstra2010-06-082-62/+73
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | PROVE_RCU has a few issues with the cpu_cgroup because the scheduler typically holds rq->lock around the css rcu derefs but the generic cgroup code doesn't (and can't) know about that lock. Provide means to add extra checks to the css dereference and use that in the scheduler to annotate its users. The addition of rq->lock to these checks is correct because the cgroup_subsys::attach() method takes the rq->lock for each task it moves, therefore by holding that lock, we ensure the task is pinned to the current cgroup and the RCU derefence is valid. That leaves one genuine race in __sched_setscheduler() where we used task_group() without holding any of the required locks and thus raced with the cgroup code. Solve this by moving the check under the appropriate lock. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | | | Merge branch 'timers-fixes-for-linus' of ↵Linus Torvalds2010-06-281-4/+1
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: nohz: Fix nohz ratelimit
| * | | | | | nohz: Fix nohz ratelimitPeter Zijlstra2010-06-171-4/+1
| | |_|_|_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Chris Wedgwood reports that 39c0cbe (sched: Rate-limit nohz) causes a serial console regression, unresponsiveness, and indeed it does. The reason is that the nohz code is skipped even when the tick was already stopped before the nohz_ratelimit(cpu) condition changed. Move the nohz_ratelimit() check to the other conditions which prevent long idle sleeps. Reported-by: Chris Wedgwood <cw@f00f.org> Tested-by: Brian Bloniarz <bmb@athenacr.com> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Greg KH <gregkh@suse.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: Jef Driesen <jefdriesen@telenet.be> LKML-Reference: <1276790557.27822.516.camel@twins> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | | | | | Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds2010-06-283-2/+13
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: silence PROVE_RCU in sched_fork() idr: fix RCU lockdep splat in idr_get_next() rcu: apply RCU protection to wake_affine()
| * | | | | | sched: silence PROVE_RCU in sched_fork()Peter Zijlstra2010-06-231-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Because cgroup_fork() is ran before sched_fork() [ from copy_process() ] and the child's pid is not yet visible the child is pinned to its cgroup. Therefore we can silence this warning. A nicer solution would be moving cgroup_fork() to right after dup_task_struct() and exclude PF_STARTING from task_subsys_state(). Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| * | | | | | idr: fix RCU lockdep splat in idr_get_next()Paul E. McKenney2010-06-231-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Convert to rcu_dereference_raw() given that many callers may have many different locking models. Located-by: Miles Lane <miles.lane@gmail.com> Tested-by: Miles Lane <miles.lane@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| * | | | | | rcu: apply RCU protection to wake_affine()Daniel J Blueman2010-06-231-0/+2
| |/ / / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The task_group() function returns a pointer that must be protected by either RCU, the ->alloc_lock, or the cgroup lock (see the rcu_dereference_check() in task_subsys_state(), which is invoked by task_group()). The wake_affine() function currently does none of these, which means that a concurrent update would be within its rights to free the structure returned by task_group(). Because wake_affine() uses this structure only to compute load-balancing heuristics, there is no reason to acquire either of the two locks. Therefore, this commit introduces an RCU read-side critical section that starts before the first call to task_group() and ends after the last use of the "tg" pointer returned from task_group(). Thanks to Li Zefan for pointing out the need to extend the RCU read-side critical section from that proposed by the original patch. Signed-off-by: Daniel J Blueman <daniel.blueman@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
* | | | | | Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds2010-06-2814-24/+45
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, Calgary: Increase max PHB number x86: Fix rebooting on Dell Precision WorkStation T7400 x86: Fix vsyscall on gcc 4.5 with -Os x86, pat: Proper init of memtype subtree_max_end um, hweight: Fix UML boot crash due to x86 optimized hweight x86, setup: Set ax register in boot vga query percpu, x86: Avoid warnings of unused variables in per cpu x86, irq: Rename gsi_end gsi_top, and fix off by one errors x86: use __ASSEMBLY__ rather than __ASSEMBLER__
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