Vlastimil Babka 172400c69c mm: fix kcompactd hang during memory offlining ... Assume memory47 is the last online block left in node1. This will hang: # echo offline > /sys/devices/system/node/node1/memory47/state After a couple of minutes, the following pops up in dmesg: INFO: task bash:957 blocked for more than 120 seconds. Not tainted 4.6.0-rc6+ #6 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. bash D ffff8800b7adbaf8 0 957 951 0x00000000 Call Trace: schedule+0x35/0x80 schedule_timeout+0x1ac/0x270 wait_for_completion+0xe1/0x120 kthread_stop+0x4f/0x110 kcompactd_stop+0x26/0x40 __offline_pages.constprop.28+0x7e6/0x840 offline_pages+0x11/0x20 memory_block_action+0x73/0x1d0 memory_subsys_offline+0x47/0x60 device_offline+0x86/0xb0 store_mem_state+0xda/0xf0 dev_attr_store+0x18/0x30 sysfs_kf_write+0x37/0x40 kernfs_fop_write+0x11d/0x170 __vfs_write+0x37/0x120 vfs_write+0xa9/0x1a0 SyS_write+0x55/0xc0 entry_SYSCALL_64_fastpath+0x1a/0xa4 kcompactd is waiting for kcompactd_max_order > 0 when it's woken up to actually exit. Check kthread_should_stop() to break out of the wait. Fixes: 698b1b306 ("mm, compaction: introduce kcompactd"). Reported-by: Reza Arbab <arbab@linux.vnet.ibm.com> Tested-by: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: David Rientjes <rientjes@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2016-05-05 17:38:53 -07:00
..
kasan
backing-dev.c
balloon_compaction.c
bootmem.c
cleancache.c
cma_debug.c
cma.c
cma.h
compaction.c	mm: fix kcompactd hang during memory offlining	2016-05-05 17:38:53 -07:00
debug_page_ref.c
debug.c
dmapool.c
early_ioremap.c
fadvise.c
failslab.c
filemap.c
frame_vector.c
frontswap.c
gup.c
highmem.c
huge_memory.c
hugetlb_cgroup.c
hugetlb.c
hwpoison-inject.c
init-mm.c
internal.h
interval_tree.c
Kconfig
Kconfig.debug
kmemcheck.c
kmemleak-test.c
kmemleak.c
ksm.c
list_lru.c
maccess.c
madvise.c
Makefile
memblock.c
memcontrol.c
memory_hotplug.c
memory-failure.c
memory.c
mempolicy.c
mempool.c
memtest.c
migrate.c
mincore.c
mlock.c
mm_init.c
mmap.c
mmu_context.c
mmu_notifier.c
mmzone.c
mprotect.c
mremap.c
msync.c
nobootmem.c
nommu.c
oom_kill.c
page_alloc.c
page_counter.c
page_ext.c
page_idle.c
page_io.c
page_isolation.c
page_owner.c
page_poison.c
page-writeback.c
pagewalk.c
percpu-km.c
percpu-vm.c
percpu.c
pgtable-generic.c
process_vm_access.c
quicklist.c
readahead.c
rmap.c
shmem.c
slab_common.c
slab.c
slab.h
slob.c
slub.c
sparse-vmemmap.c
sparse.c
swap_cgroup.c
swap_state.c
swap.c
swapfile.c
truncate.c
userfaultfd.c
util.c
vmacache.c
vmalloc.c
vmpressure.c
vmscan.c
vmstat.c
workingset.c
zbud.c
zpool.c
zsmalloc.c
zswap.c