- 25 Mar, 2016 40 commits
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Ryan Ding authored
Take ip_alloc_sem to prevent concurrent access to extent tree, which may cause the extent tree in an unstable state. Signed-off-by: Ryan Ding <ryan.ding@oracle.com> Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Ryan Ding authored
In the current implementation of unaligned aio+dio, lock order behave as follow: in user process context: -> call io_submit() -> get i_mutex <== window1 -> get ip_unaligned_aio -> submit direct io to block device -> release i_mutex -> io_submit() return in dio work queue context(the work queue is created in __blockdev_direct_IO): -> release ip_unaligned_aio <== window2 -> get i_mutex -> clear unwritten flag & change i_size -> release i_mutex There is a limitation to the thread number of dio work queue. 256 at default. If all 256 thread are in the above 'window2' stage, and there is a user process in the 'window1' stage, the system will became deadlock. Since the user process hold i_mutex to wait ip_unaligned_aio lock, while there is a direct bio hold ip_unaligned_aio mutex who is waiting for a dio work queue thread to be schedule. But all the dio work queue thread is waiting for i_mutex lock in 'window2'. This case only happened in a test which send a large number(more than 256) of aio at one io_submit() call. My design is to remove ip_unaligned_aio lock. Change it to a sync io instead. Just like ip_unaligned_aio lock, serialize the unaligned aio dio. [akpm@linux-foundation.org: remove OCFS2_IOCB_UNALIGNED_IO, per Junxiao Bi] Signed-off-by: Ryan Ding <ryan.ding@oracle.com> Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Ryan Ding authored
Clean up ocfs2_file_write_iter & ocfs2_prepare_inode_for_write: * remove append dio check: it will be checked in ocfs2_direct_IO() * remove file hole check: file hole is supported for now * remove inline data check: it will be checked in ocfs2_direct_IO() * remove the full_coherence check when append dio: we will get the inode_lock in ocfs2_dio_get_block, there is no need to fall back to buffer io to ensure the coherence semantics. Now the drop dio procedure is gone. :) [akpm@linux-foundation.org: remove unused label] Signed-off-by: Ryan Ding <ryan.ding@oracle.com> Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Ryan Ding authored
There are mainly three issues in the direct io code path after commit 24c40b32 ("ocfs2: implement ocfs2_direct_IO_write"): * Does not support sparse file. * Does not support data ordering. eg: when write to a file hole, it will alloc extent first. If system crashed before io finished, data will corrupt. * Potential risk when doing aio+dio. The -EIOCBQUEUED return value is likely to be ignored by ocfs2_direct_IO_write(). To resolve above problems, re-design direct io code with following ideas: * Use buffer io to fill in holes. And this will make better performance also. * Clear unwritten after direct write finished. So we can make sure meta data changes after data write to disk. (Unwritten extent is invisible to user, from user's view, meta data is not changed when allocate an unwritten extent.) * Clear ocfs2_direct_IO_write(). Do all ending work in end_io. This patch has passed fs,dio,ltp-aiodio.part1,ltp-aiodio.part2,ltp-aiodio.part4 test cases of ltp. For performance improvement, see following test result: ocfs2 cluster size 1MB, ocfs2 volume is mounted on /mnt/. The original way: + rm /mnt/test.img -f + dd if=/dev/zero of=/mnt/test.img bs=4K count=1048576 oflag=direct 1048576+0 records in 1048576+0 records out 4294967296 bytes (4.3 GB) copied, 1707.83 s, 2.5 MB/s + rm /mnt/test.img -f + dd if=/dev/zero of=/mnt/test.img bs=256K count=16384 oflag=direct 16384+0 records in 16384+0 records out 4294967296 bytes (4.3 GB) copied, 582.705 s, 7.4 MB/s After this patch: + rm /mnt/test.img -f + dd if=/dev/zero of=/mnt/test.img bs=4K count=1048576 oflag=direct 1048576+0 records in 1048576+0 records out 4294967296 bytes (4.3 GB) copied, 64.6412 s, 66.4 MB/s + rm /mnt/test.img -f + dd if=/dev/zero of=/mnt/test.img bs=256K count=16384 oflag=direct 16384+0 records in 16384+0 records out 4294967296 bytes (4.3 GB) copied, 34.7611 s, 124 MB/s Signed-off-by: Ryan Ding <ryan.ding@oracle.com> Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Ryan Ding authored
To support direct io in ocfs2_write_begin_nolock & ocfs2_write_end_nolock. There is still one issue in the direct write procedure. phase 1: alloc extent with UNWRITTEN flag phase 2: submit direct data to disk, add zero page to page cache phase 3: clear UNWRITTEN flag when data has been written to disk When there are 2 direct write A(0~3KB),B(4~7KB) writing to the same cluster 0~7KB (cluster size 8KB). Write request A arrive phase 2 first, it will zero the region (4~7KB). Before request A enter to phase 3, request B arrive phase 2, it will zero region (0~3KB). This is just like request B steps request A. To resolve this issue, we should let request B knows this cluster is already under zero, to prevent it from steps the previous write request. This patch will add function ocfs2_unwritten_check() to do this job. It will record all clusters that are under direct write(it will be recorded in the 'ip_unwritten_list' member of inode info), and prevent the later direct write writing to the same cluster to do the zero work again. Signed-off-by: Ryan Ding <ryan.ding@oracle.com> Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Ryan Ding authored
To support direct io in ocfs2_write_begin_nolock & ocfs2_write_end_nolock. Direct io needs to get the physical address from write_begin, to map the user page. This patch is to change the arg 'phys' of ocfs2_write_cluster to a pointer, so it can be retrieved to write_begin. And we can retrieve it to the direct io procedure. Signed-off-by: Ryan Ding <ryan.ding@oracle.com> Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Ryan Ding authored
To support direct io in ocfs2_write_begin_nolock & ocfs2_write_end_nolock. Append direct io do not change i_size in get block phase. It only move to orphan when starting write. After data is written to disk, it will delete itself from orphan and update i_size. So skip i_size change section in write_begin for direct io. And when there is no extents alloc, no meta data changes needed for direct io (since write_begin start trans for 2 reason: alloc extents & change i_size. Now none of them needed). So we can skip start trans procedure. Signed-off-by: Ryan Ding <ryan.ding@oracle.com> Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Ryan Ding authored
To support direct io in ocfs2_write_begin_nolock & ocfs2_write_end_nolock. Direct io data will not appear in buffer. The w_target_page member will not be filled by direct io. So avoid to use it when it's NULL. Unlinke buffer io and mmap, direct io will call write_begin with more than 1 page a time. So the target_index is not sufficient to describe the actual data. change it to a range start at target_index, end in end_index. Signed-off-by: Ryan Ding <ryan.ding@oracle.com> Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Ryan Ding authored
To support direct io in ocfs2_write_begin_nolock & ocfs2_write_end_nolock. There is a problem in ocfs2's direct io implement: if system crashed after extents allocated, and before data return, we will get a extent with dirty data on disk. This problem violate the journal=order semantics, which means meta changes take effect after data written to disk. To resolve this issue, direct write can use the UNWRITTEN flag to describe a extent during direct data writeback. The direct write procedure should act in the following order: phase 1: alloc extent with UNWRITTEN flag phase 2: submit direct data to disk, add zero page to page cache phase 3: clear UNWRITTEN flag when data has been written to disk This patch is to change the 'c_unwritten' member of ocfs2_write_cluster_desc to 'c_clear_unwritten'. Means whether to clear the unwritten flag. It do not care if a extent is allocated or not. And use 'c_new' to specify a newly allocated extent. So the direct io procedure can use c_clear_unwritten to control the UNWRITTEN bit on extent. Signed-off-by: Ryan Ding <ryan.ding@oracle.com> Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Ryan Ding authored
Patchset: fix ocfs2 direct io code patch to support sparse file and data ordering semantics The idea is to use buffer io(more precisely use the interface ocfs2_write_begin_nolock & ocfs2_write_end_nolock) to do the zero work beyond block size. And clear UNWRITTEN flag until direct io data has been written to disk, which can prevent data corruption when system crashed during direct write. And we will also archive a better performance: eg. dd direct write new file with block size 4KB: before this patchset: 2.5 MB/s after this patchset: 66.4 MB/s This patch (of 8): To support direct io in ocfs2_write_begin_nolock & ocfs2_write_end_nolock. Remove unused args filp & flags. Add new arg type. The type is one of buffer/direct/mmap. Indicate 3 way to perform write. buffer/mmap type has implemented. direct type will be implemented later. Signed-off-by: Ryan Ding <ryan.ding@oracle.com> Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Junxiao Bi authored
This is a regression issue and caused the following kernel panic when do ocfs2 multiple test. BUG: unable to handle kernel paging request at 00000002000800c0 IP: [<ffffffff81192978>] kmem_cache_alloc+0x78/0x160 PGD 7bbe5067 PUD 0 Oops: 0000 [#1] SMP Modules linked in: ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm ocfs2_nodemanager ocfs2_stackglue iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi xen_kbdfront xen_netfront xen_fbfront xen_blkfront CPU: 2 PID: 4044 Comm: mpirun Not tainted 4.5.0-rc5-next-20160225 #1 Hardware name: Xen HVM domU, BIOS 4.3.1OVM 05/14/2014 task: ffff88007a521a80 ti: ffff88007aed0000 task.ti: ffff88007aed0000 RIP: 0010:[<ffffffff81192978>] [<ffffffff81192978>] kmem_cache_alloc+0x78/0x160 RSP: 0018:ffff88007aed3a48 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000001991 RDX: 0000000000001990 RSI: 00000000024000c0 RDI: 000000000001b330 RBP: ffff88007aed3a98 R08: ffff88007d29b330 R09: 00000002000800c0 R10: 0000000c51376d87 R11: ffff8800792cac38 R12: ffff88007cc30f00 R13: 00000000024000c0 R14: ffffffff811b053f R15: ffff88007aed3ce7 FS: 0000000000000000(0000) GS:ffff88007d280000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000002000800c0 CR3: 000000007aeb2000 CR4: 00000000000406e0 Call Trace: __d_alloc+0x2f/0x1a0 d_alloc+0x17/0x80 lookup_dcache+0x8a/0xc0 path_openat+0x3c3/0x1210 do_filp_open+0x80/0xe0 do_sys_open+0x110/0x200 SyS_open+0x19/0x20 do_syscall_64+0x72/0x230 entry_SYSCALL64_slow_path+0x25/0x25 Code: 05 e6 77 e7 7e 4d 8b 08 49 8b 40 10 4d 85 c9 0f 84 dd 00 00 00 48 85 c0 0f 84 d4 00 00 00 49 63 44 24 20 49 8b 3c 24 48 8d 4a 01 <49> 8b 1c 01 4c 89 c8 65 48 0f c7 0f 0f 94 c0 3c 01 75 b6 49 63 RIP kmem_cache_alloc+0x78/0x160 CR2: 00000002000800c0 ---[ end trace 823969e602e4aaac ]--- Fixes: a4a1dfa4("ocfs2/cluster: fix memory leak in o2hb_region_release") Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Reviewed-by: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Andrew Morton authored
INPUT_COMPAT_TEST became much simpler after commit f4056b52 ("input: redefine INPUT_COMPAT_TEST as in_compat_syscall()") so we can cleanly eliminate it altogether. Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Tetsuo Handa authored
"oom, oom_reaper: disable oom_reaper for oom_kill_allocating_task" tried to protect oom_reaper_list using MMF_OOM_KILLED flag. But we can do it by simply checking tsk->oom_reaper_list != NULL. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Michal Hocko authored
After "oom: clear TIF_MEMDIE after oom_reaper managed to unmap the address space" oom_reaper will call exit_oom_victim on the target task after it is done. This might however race with the PM freezer: CPU0 CPU1 CPU2 freeze_processes try_to_freeze_tasks # Allocation request out_of_memory oom_killer_disable wake_oom_reaper(P1) __oom_reap_task exit_oom_victim(P1) wait_event(oom_victims==0) [...] do_exit(P1) perform IO/interfere with the freezer which breaks the oom_killer_disable semantic. We no longer have a guarantee that the oom victim won't interfere with the freezer because it might be anywhere on the way to do_exit while the freezer thinks the task has already terminated. It might trigger IO or touch devices which are frozen already. In order to close this race, make the oom_reaper thread freezable. This will work because a) already running oom_reaper will block freezer to enter the quiescent state b) wake_oom_reaper will not wake up the reaper after it has been frozen c) the only way to call exit_oom_victim after try_to_freeze_tasks is from the oom victim's context when we know the further interference shouldn't be possible Signed-off-by: Michal Hocko <mhocko@suse.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Vladimir Davydov authored
Entries are only added/removed from oom_reaper_list at head so we can use a single linked list and hence save a word in task_struct. Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Michal Hocko <mhocko@suse.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Michal Hocko authored
Tetsuo has reported that oom_kill_allocating_task=1 will cause oom_reaper_list corruption because oom_kill_process doesn't follow standard OOM exclusion (aka ignores TIF_MEMDIE) and allows to enqueue the same task multiple times - e.g. by sacrificing the same child multiple times. This patch fixes the issue by introducing a new MMF_OOM_KILLED mm flag which is set in oom_kill_process atomically and oom reaper is disabled if the flag was already set. Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Michal Hocko authored
wake_oom_reaper has allowed only 1 oom victim to be queued. The main reason for that was the simplicity as other solutions would require some way of queuing. The current approach is racy and that was deemed sufficient as the oom_reaper is considered a best effort approach to help with oom handling when the OOM victim cannot terminate in a reasonable time. The race could lead to missing an oom victim which can get stuck out_of_memory wake_oom_reaper cmpxchg // OK oom_reaper oom_reap_task __oom_reap_task oom_victim terminates atomic_inc_not_zero // fail out_of_memory wake_oom_reaper cmpxchg // fails task_to_reap = NULL This race requires 2 OOM invocations in a short time period which is not very likely but certainly not impossible. E.g. the original victim might have not released a lot of memory for some reason. The situation would improve considerably if wake_oom_reaper used a more robust queuing. This is what this patch implements. This means adding oom_reaper_list list_head into task_struct (eat a hole before embeded thread_struct for that purpose) and a oom_reaper_lock spinlock for queuing synchronization. wake_oom_reaper will then add the task on the queue and oom_reaper will dequeue it. Signed-off-by: Michal Hocko <mhocko@suse.com> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Andrea Argangeli <andrea@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Michal Hocko authored
Inform about the successful/failed oom_reaper attempts and dump all the held locks to tell us more who is blocking the progress. [akpm@linux-foundation.org: fix CONFIG_MMU=n build] Signed-off-by: Michal Hocko <mhocko@suse.com> Cc: Andrea Argangeli <andrea@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Michal Hocko authored
When oom_reaper manages to unmap all the eligible vmas there shouldn't be much of the freable memory held by the oom victim left anymore so it makes sense to clear the TIF_MEMDIE flag for the victim and allow the OOM killer to select another task. The lack of TIF_MEMDIE also means that the victim cannot access memory reserves anymore but that shouldn't be a problem because it would get the access again if it needs to allocate and hits the OOM killer again due to the fatal_signal_pending resp. PF_EXITING check. We can safely hide the task from the OOM killer because it is clearly not a good candidate anymore as everyhing reclaimable has been torn down already. This patch will allow to cap the time an OOM victim can keep TIF_MEMDIE and thus hold off further global OOM killer actions granted the oom reaper is able to take mmap_sem for the associated mm struct. This is not guaranteed now but further steps should make sure that mmap_sem for write should be blocked killable which will help to reduce such a lock contention. This is not done by this patch. Note that exit_oom_victim might be called on a remote task from __oom_reap_task now so we have to check and clear the flag atomically otherwise we might race and underflow oom_victims or wake up waiters too early. Signed-off-by: Michal Hocko <mhocko@suse.com> Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Suggested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Andrea Argangeli <andrea@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Michal Hocko authored
This patch (of 5): This is based on the idea from Mel Gorman discussed during LSFMM 2015 and independently brought up by Oleg Nesterov. The OOM killer currently allows to kill only a single task in a good hope that the task will terminate in a reasonable time and frees up its memory. Such a task (oom victim) will get an access to memory reserves via mark_oom_victim to allow a forward progress should there be a need for additional memory during exit path. It has been shown (e.g. by Tetsuo Handa) that it is not that hard to construct workloads which break the core assumption mentioned above and the OOM victim might take unbounded amount of time to exit because it might be blocked in the uninterruptible state waiting for an event (e.g. lock) which is blocked by another task looping in the page allocator. This patch reduces the probability of such a lockup by introducing a specialized kernel thread (oom_reaper) which tries to reclaim additional memory by preemptively reaping the anonymous or swapped out memory owned by the oom victim under an assumption that such a memory won't be needed when its owner is killed and kicked from the userspace anyway. There is one notable exception to this, though, if the OOM victim was in the process of coredumping the result would be incomplete. This is considered a reasonable constrain because the overall system health is more important than debugability of a particular application. A kernel thread has been chosen because we need a reliable way of invocation so workqueue context is not appropriate because all the workers might be busy (e.g. allocating memory). Kswapd which sounds like another good fit is not appropriate as well because it might get blocked on locks during reclaim as well. oom_reaper has to take mmap_sem on the target task for reading so the solution is not 100% because the semaphore might be held or blocked for write but the probability is reduced considerably wrt. basically any lock blocking forward progress as described above. In order to prevent from blocking on the lock without any forward progress we are using only a trylock and retry 10 times with a short sleep in between. Users of mmap_sem which need it for write should be carefully reviewed to use _killable waiting as much as possible and reduce allocations requests done with the lock held to absolute minimum to reduce the risk even further. The API between oom killer and oom reaper is quite trivial. wake_oom_reaper updates mm_to_reap with cmpxchg to guarantee only NULL->mm transition and oom_reaper clear this atomically once it is done with the work. This means that only a single mm_struct can be reaped at the time. As the operation is potentially disruptive we are trying to limit it to the ncessary minimum and the reaper blocks any updates while it operates on an mm. mm_struct is pinned by mm_count to allow parallel exit_mmap and a race is detected by atomic_inc_not_zero(mm_users). Signed-off-by: Michal Hocko <mhocko@suse.com> Suggested-by: Oleg Nesterov <oleg@redhat.com> Suggested-by: Mel Gorman <mgorman@suse.de> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Andrea Argangeli <andrea@kernel.org> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Andrew Morton authored
This will be needed in the patch "mm, oom: introduce oom reaper". Acked-by: Michal Hocko <mhocko@suse.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Linus Torvalds authored
This reverts commit e7223f18. It causes problems when a ppdev tries to register before the parport driver has been registered with the device model. That will trigger the BUG_ON(!drv->bus->p); at drivers/base/driver.c:153. The call chain is kernel_init -> kernel_init_freeable -> do_one_initcall -> ppdev_init -> __parport_register_driver -> driver_register *BOOM* Reported-by: kernel test robot <fengguang.wu@intel.com> Reported-by: Ross Zwisler <zwisler@gmail.com> Reported-by: Petr Mladek <pmladek@suse.com> Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394Linus Torvalds authored
Pull firewire leftover from Stefan Richter: "Occurrences of timeval were supposed to be eliminated last round, now remove a last forgotten one" * tag 'firewire-update2' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394: firewire: nosy: Replace timeval with timespec64
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git://people.freedesktop.org/~airlied/linuxLinus Torvalds authored
Pull drm fixes from Dave Airlie: "Just a couple of dma-buf related fixes and some amdgpu fixes, along with a regression fix for radeon off but default feature, but makes my 30" monitor happy again" * 'drm-next' of git://people.freedesktop.org/~airlied/linux: drm/radeon/mst: cleanup code indentation drm/radeon/mst: fix regression in lane/link handling. drm/amdgpu: add invalidate_page callback for userptrs drm/amdgpu: Revert "remove the userptr rmn->lock" drm/amdgpu: clean up path handling for powerplay drm/amd/powerplay: fix memory leak of tdp_table dma-buf/fence: fix fence_is_later v2 dma-buf: Update docs for SYNC ioctl drm: remove excess description dma-buf, drm, ion: Propagate error code from dma_buf_start_cpu_access() drm/atmel-hlcdc: use helper to get crtc state drm/atomic: use helper to get crtc state
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git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-genericLinus Torvalds authored
Pull asm-generic updates from Arnd Bergmann: "There are only three patches this time, most other changes to files in include/asm-generic tend to go through the tree of whoever depends on the change. Two patches are cleanups for stuff that is no longer needed, the main change is to adapt the generic version of BUG_ON() for CONFIG_BUG=n to make it behave consistently with BUG(). This avoids undefined behavior along with a number of warnings about that undefined behavior in randconfig builds when we keep going on after hitting a BUG_ON()" * tag 'asm-generic-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: asm-generic: remove old nonatomic-io wrapper files asm-generic: default BUG_ON(x) to if(x)BUG() asm-generic: page.h: Remove useless get_user_page and free_user_page
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git://people.freedesktop.org/~agd5f/linuxDave Airlie authored
some amd fixes * 'drm-next-4.6' of git://people.freedesktop.org/~agd5f/linux: drm/radeon/mst: cleanup code indentation drm/radeon/mst: fix regression in lane/link handling. drm/amdgpu: add invalidate_page callback for userptrs drm/amdgpu: Revert "remove the userptr rmn->lock" drm/amdgpu: clean up path handling for powerplay drm/amd/powerplay: fix memory leak of tdp_table
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git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pmLinus Torvalds authored
Pull more power management and ACPI updates from Rafael Wysocki: "The second batch of power management and ACPI updates for v4.6. Included are fixups on top of the previous PM/ACPI pull request and other material that didn't make into it but still should go into 4.6. Among other things, there's a fix for an intel_pstate driver issue uncovered by recent cpufreq changes, a workaround for a boot hang on Skylake-H related to the handling of deep C-states by the platform and a PCI/ACPI fix for the handling of IO port resources on non-x86 architectures plus some new device IDs and similar. Specifics: - Fix for an intel_pstate driver issue related to the handling of MSR updates uncovered by the recent cpufreq rework (Rafael Wysocki). - cpufreq core cleanups related to starting governors and frequency synchronization during resume from system suspend and a locking fix for cpufreq_quick_get() (Rafael Wysocki, Richard Cochran). - acpi-cpufreq and powernv cpufreq driver updates (Jisheng Zhang, Michael Neuling, Richard Cochran, Shilpasri Bhat). - intel_idle driver update preventing some Skylake-H systems from hanging during initialization by disabling deep C-states mishandled by the platform in the problematic configurations (Len Brown). - Intel Xeon Phi Processor x200 support for intel_idle (Dasaratharaman Chandramouli). - cpuidle menu governor updates to make it always honor PM QoS latency constraints (and prevent C1 from being used as the fallback C-state on x86 when they are set below its exit latency) and to restore the previous behavior to fall back to C1 if the next timer event is set far enough in the future that was changed in 4.4 which led to an energy consumption regression (Rik van Riel, Rafael Wysocki). - New device ID for a future AMD UART controller in the ACPI driver for AMD SoCs (Wang Hongcheng). - Rockchip rk3399 support for the rockchip-io-domain adaptive voltage scaling (AVS) driver (David Wu). - ACPI PCI resources management fix for the handling of IO space resources on architectures where the IO space is memory mapped (IA64 and ARM64) broken by the introduction of common ACPI resources parsing for PCI host bridges in 4.4 (Lorenzo Pieralisi). - Fix for the ACPI backend of the generic device properties API to make it parse non-device (data node only) children of an ACPI device correctly (Irina Tirdea). - Fixes for the handling of global suspend flags (introduced in 4.4) during hibernation and resume from it (Lukas Wunner). - Support for obtaining configuration information from Device Trees in the PM clocks framework (Jon Hunter). - ACPI _DSM helper code and devfreq framework cleanups (Colin Ian King, Geert Uytterhoeven)" * tag 'pm+acpi-4.6-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (23 commits) PM / AVS: rockchip-io: add io selectors and supplies for rk3399 intel_idle: Support for Intel Xeon Phi Processor x200 Product Family intel_idle: prevent SKL-H boot failure when C8+C9+C10 enabled ACPI / PM: Runtime resume devices when waking from hibernate PM / sleep: Clear pm_suspend_global_flags upon hibernate cpufreq: governor: Always schedule work on the CPU running update cpufreq: Always update current frequency before startig governor cpufreq: Introduce cpufreq_update_current_freq() cpufreq: Introduce cpufreq_start_governor() cpufreq: powernv: Add sysfs attributes to show throttle stats cpufreq: acpi-cpufreq: make Intel/AMD MSR access, io port access static PCI: ACPI: IA64: fix IO port generic range check ACPI / util: cast data to u64 before shifting to fix sign extension cpufreq: powernv: Define per_cpu chip pointer to optimize hot-path cpuidle: menu: Fall back to polling if next timer event is near cpufreq: acpi-cpufreq: Clean up hot plug notifier callback intel_pstate: Do not call wrmsrl_on_cpu() with disabled interrupts cpufreq: Make cpufreq_quick_get() safe to call ACPI / property: fix data node parsing in acpi_get_next_subnode() ACPI / APD: Add device HID for future AMD UART controller ...
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git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linuxLinus Torvalds authored
Pull more RTC updates from Alexandre Belloni: "A second pull request for v4.6 with a few fixesi before -rc1. The new features for abx80x actually make the RTC behave correctly. Drivers: - abx80x: handle both XT and RC oscillators, XT failure bit and autocalibration - m41t80: avoid out of range year values - rv8803: workaround an i2c HW issue" * tag 'rtc-4.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: rtc: abx80x: handle the oscillator failure bit rtc: abx80x: handle autocalibration rtc: rv8803: workaround i2c HW issue rtc: mcp795: add devicetree support rtc: asm9260: remove incorrect __init/__exit annotations rtc: m41t80: avoid out of range year values rtc: s3c: Don't print an error on probe deferral rtc: rv3029: stop mentioning rv3029c2
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Linus Torvalds authored
Merge tag 'hwmon-for-linus-v4.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging Pull more hwmon updates from Guenter Roeck: "Update hwmon mailing list and web page" * tag 'hwmon-for-linus-v4.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging: MAINTAINERS: Update mailing list and web page for hwmon subsystem
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git://git.kernel.dk/linux-blockLinus Torvalds authored
Pull block fixes from Jens Axboe: "Final round of fixes for this merge window - some of this has come up after the initial pull request, and some of it was put in a post-merge branch before the merge window. This contains: - Fix for a bad check for an error on dma mapping in the mtip32xx driver, from Alexey Khoroshilov. - A set of fixes for lightnvm, from Javier, Matias, and Wenwei. - An NVMe completion record corruption fix from Marta, ensuring that we read things in the right order. - Two writeback fixes from Tejun, marked for stable@ as well. - A blk-mq sw queue iterator fix from Thomas, fixing an oops for sparse CPU maps. They hit this in the hot plug/unplug rework" * 'for-linus' of git://git.kernel.dk/linux-block: nvme: avoid cqe corruption when update at the same time as read writeback, cgroup: fix use of the wrong bdi_writeback which mismatches the inode writeback, cgroup: fix premature wb_put() in locked_inode_to_wb_and_lock_list() blk-mq: Use proper cpumask iterator mtip32xx: fix checks for dma mapping errors lightnvm: do not load L2P table if not supported lightnvm: do not reserve lun on l2p loading nvme: lightnvm: return ppa completion status lightnvm: add a bitmap of luns lightnvm: specify target's logical address area null_blk: add lightnvm null_blk device to the nullb_list
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git://git.infradead.org/linux-mtdLinus Torvalds authored
Pull MTD updates from Brian Norris: "NAND: - Add sunxi_nand randomizer support - begin refactoring NAND ecclayout structs - fix pxa3xx_nand dmaengine usage - brcmnand: fix support for v7.1 controller - add Qualcomm NAND controller driver SPI NOR: - add new ls1021a, ls2080a support to Freescale QuadSPI - add new flash ID entries - support bottom-block protection for Winbond flash - support Status Register Write Protect - remove broken QPI support for Micron SPI flash JFFS2: - improve post-mount CRC scan efficiency General: - refactor bcm63xxpart parser, to later extend for NAND - add writebuf size parameter to mtdram Other minor code quality improvements" * tag 'for-linus-20160324' of git://git.infradead.org/linux-mtd: (72 commits) mtd: nand: remove kerneldoc for removed function parameter mtd: nand: Qualcomm NAND controller driver dt/bindings: qcom_nandc: Add DT bindings mtd: nand: don't select chip in nand_chip's block_bad op mtd: spi-nor: support lock/unlock for a few Winbond chips mtd: spi-nor: add TB (Top/Bottom) protect support mtd: spi-nor: add SPI_NOR_HAS_LOCK flag mtd: spi-nor: use BIT() for flash_info flags mtd: spi-nor: disallow further writes to SR if WP# is low mtd: spi-nor: make lock/unlock bounds checks more obvious and robust mtd: spi-nor: silently drop lock/unlock for already locked/unlocked region mtd: spi-nor: wait for SR_WIP to clear on initial unlock mtd: nand: simplify nand_bch_init() usage mtd: mtdswap: remove useless if (!mtd->ecclayout) test mtd: create an mtd_oobavail() helper and make use of it mtd: kill the ecclayout->oobavail field mtd: nand: check status before reporting timeout mtd: bcm63xxpart: give width specifier an 'int', not 'size_t' mtd: mtdram: Add parameter for setting writebuf size mtd: nand: pxa3xx_nand: kill unused field 'drcmr_cmd' ...
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git://git.infradead.org/linux-ubifsLinus Torvalds authored
Pull UBI/UBIFS updates from Richard Weinberger: "This contains cleanups and a maintainer update for UBI and UBIFS" * tag 'upstream-4.6-rc1' of git://git.infradead.org/linux-ubifs: ubifs: Remove unused header MAINTAINERS: Update UBIFS entry mtd: ubi: Add logging functions ubi_msg, ubi_warn and ubi_err ubifs: Add logging functions for ubifs_msg, ubifs_err and ubifs_warn
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git://linux-nfs.org/~bfields/linuxLinus Torvalds authored
Pull more nfsd updates from Bruce Fields: "Apologies for the previous request, which omitted the top 8 commits from my for-next branch (including the SCSI layout commits). Thanks to Trond for spotting my error!" This actually includes the new layout types, so here's that part of the pull message repeated: "Support for a new pnfs layout type from Christoph Hellwig. The new layout type is a variant of the block layout which uses SCSI features to offer improved fencing and device identification. Note this pull request also includes the client side of SCSI layout, with Trond's permission" * tag 'nfsd-4.6-1' of git://linux-nfs.org/~bfields/linux: nfsd: use short read as well as i_size to set eof nfsd: better layoutupdate bounds-checking nfsd: block and scsi layout drivers need to depend on CONFIG_BLOCK nfsd: add SCSI layout support nfsd: move some blocklayout code nfsd: add a new config option for the block layout driver nfs/blocklayout: add SCSI layout support nfs4.h: add SCSI layout definitions
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git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuildLinus Torvalds authored
Pull kbuild misc updates from Michal Marek: "The non-critical part of kbuild for v4.6-rc1: - coccinelle cleanup and a new patch - make tags rule for kprobe helpers - make rpm fix to avoid spurious grub2 entries - make rpm support for %postun script (Fedora only at the moment)" * 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: kbuild/mkspec: clean boot loader configuration on rpm removal kbuild/mkspec: fix grub2 installkernel issue Coccinelle: Add api/setup_timer.cocci coccinelle: bugon: reduce rule applicability Coccinelle: pm_runtime: reduce rule applicability Coccinelle: array_size: reduce rule applicability Coccinelle: reduce rule applicability scripts/tags.sh: add regex to map kprobe helpers scripts/coccinelle: modernize &
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git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuildLinus Torvalds authored
Pull kconfig updates from Michal Marek: "Just two kconfig commits this time: - kconfig Makefile fix for make 3.80 - Fix calculating symbols so that KCONFIG_ALLCONFIG=... does not disable CONFIG_MODULES silently" * 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: unbreak allmodconfig KCONFIG_ALLCONFIG=... scripts/kconfig: allow building with make 3.80 again
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git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuildLinus Torvalds authored
Pull kbuild updates from Michal Marek: - make dtbs_install fix - Error handling fix fixdep and link-vmlinux.sh - __UNIQUE_ID fix for clang - Fix for if_changed_* to suppress the "is up to date." message - The kernel is built with -Werror=incompatible-pointer-types * 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: kbuild: Add option to turn incompatible pointer check into error kbuild: suppress annoying "... is up to date." message kbuild: fixdep: Check fstat(2) return value scripts/link-vmlinux.sh: force error on kallsyms failure Kbuild: provide a __UNIQUE_ID for clang dtbsinstall: don't move target directory out of the way
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git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linuxLinus Torvalds authored
Pull parisc updates from Helge Deller: "This patchset adds stack usage debug info for parisc and metag (on both the stack grows upwards), switches to the new generic realative extable search and sort routines, drops the long time ago removed syscalls alloc_hugepages and free_hugepages and wires up the new preadv2 and pwritev2 syscalls" * 'parisc-4.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: parisc: Wire up preadv2 and pwritev2 syscalls parisc: Use generic extable search and sort routines parisc: Panic immediately when panic_on_oops parisc,metag: Implement CONFIG_DEBUG_STACK_USAGE option parisc: Drop alloc_hugepages and free_hugepages syscalls
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git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linuxLinus Torvalds authored
Pull second set of arm64 updates from Catalin Marinas: - KASLR bug fixes: use callee-saved register, boot-time I-cache maintenance - inv_entry asm macro fix (EL0 check typo) - pr_notice("Virtual kernel memory layout...") splitting - Clean-ups: use p?d_set_huge consistently, allow preemption around copy_to_user_page, remove unused __local_flush_icache_all() * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: mm: allow preemption in copy_to_user_page arm64: consistently use p?d_set_huge arm64: kaslr: use callee saved register to preserve SCTLR across C call arm64: Split pr_notice("Virtual kernel memory layout...") into multiple pr_cont() arm64: drop unused __local_flush_icache_all() arm64: fix KASLR boot-time I-cache maintenance arm64/kernel: fix incorrect EL0 check in inv_entry macro
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git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-socLinus Torvalds authored
Pull more ARM DT changes from Arnd Bergmann: "Here are some final updates for ARM SoC specific dts files: - The i.MX changes were sent relatively late, and had a dependency on the clk tree, so I delayed that a bit. Support for the new i.MX6qp SoC and a couple of new boards is added in this branch. - Uniphier renames a few files to match the final product names that were decided by the company, kudos to the kernel developer(s) for getting support upstream before the product release. Also two boards are added. The patches were posted early enough and nice overall, but we forgot to apply them and decided to give it some more time in linux-next - at91 has two small bug fixes" * tag 'armsoc-dt2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (83 commits) ARM: dts: at91: sama5d4 Xplained: don't disable hsmci regulator ARM: dts: at91: sama5d3 Xplained: don't disable hsmci regulator ARM: dts: uniphier: add pinmux node for I2C ch4 ARM: dts: uniphier: add @{address} to EEPROM node ARM: dts: uniphier: add PH1-Pro4 Sanji board support ARM: dts: uniphier: add PH1-Pro4 Ace board support ARM: dts: uniphier: enable I2C channel 2 of ProXstream2 Gentil board ARM: dts: uniphier: add EEPROM node for ProXstream2 Gentil board ARM: dts: uniphier: add reference clock nodes ARM: dts: uniphier: rework UniPhier System Bus nodes ARM: dts: uniphier: factor out ranges property of support card arm64: dts: uniphier: rename PH1-LD10 to PH1-LD20 ARM: dts: imx53-qsb: Fix gpio button polarity ARM: dts: vfxxx: Add DAC node for Vybrid SoC ARM: dts: imx6q: add missing links between ipu2 and mipi dsi ARM: dts: imx: Add support for Advantech/GE B850v3 ARM: dts: imx: Add support for Advantech/GE B650v3 ARM: dts: imx: Add support for Advantech/GE B450v3 ARM: dts: imx: Add support for Advantech/GE Bx50v3 ARM: dts: imx: Add Advantech BA-16 Qseven module ...
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git://git.osdn.jp/gitroot/uclinux-h8/linuxLinus Torvalds authored
Pull h8300 updates from Yoshinori Sato: "Various h8300 fixes" * tag 'for-4.6' of git://git.osdn.jp/gitroot/uclinux-h8/linux: h8300: switch EARLYCON h8300: dts: Rename the serial port clock to fck
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