linux/mm
Nick Piggin cf40bd16fd lockdep: annotate reclaim context (__GFP_NOFS)
Here is another version, with the incremental patch rolled up, and
added reclaim context annotation to kswapd, and allocation tracing
to slab allocators (which may only ever reach the page allocator
in rare cases, so it is good to put annotations here too).

Haven't tested this version as such, but it should be getting closer
to merge worthy ;)

--
After noticing some code in mm/filemap.c accidentally perform a __GFP_FS
allocation when it should not have been, I thought it might be a good idea to
try to catch this kind of thing with lockdep.

I coded up a little idea that seems to work. Unfortunately the system has to
actually be in __GFP_FS page reclaim, then take the lock, before it will mark
it. But at least that might still be some orders of magnitude more common
(and more debuggable) than an actual deadlock condition, so we have some
improvement I hope (the concept is no less complete than discovery of a lock's
interrupt contexts).

I guess we could even do the same thing with __GFP_IO (normal reclaim), and
even GFP_NOIO locks too... but filesystems will have the most locks and fiddly
code paths, so let's start there and see how it goes.

It *seems* to work. I did a quick test.

=================================
[ INFO: inconsistent lock state ]
2.6.28-rc6-00007-ged31348-dirty #26
---------------------------------
inconsistent {in-reclaim-W} -> {ov-reclaim-W} usage.
modprobe/8526 [HC0[0]:SC0[0]:HE1:SE1] takes:
 (testlock){--..}, at: [<ffffffffa0020055>] brd_init+0x55/0x216 [brd]
{in-reclaim-W} state was registered at:
  [<ffffffff80267bdb>] __lock_acquire+0x75b/0x1a60
  [<ffffffff80268f71>] lock_acquire+0x91/0xc0
  [<ffffffff8070f0e1>] mutex_lock_nested+0xb1/0x310
  [<ffffffffa002002b>] brd_init+0x2b/0x216 [brd]
  [<ffffffff8020903b>] _stext+0x3b/0x170
  [<ffffffff80272ebf>] sys_init_module+0xaf/0x1e0
  [<ffffffff8020c3fb>] system_call_fastpath+0x16/0x1b
  [<ffffffffffffffff>] 0xffffffffffffffff
irq event stamp: 3929
hardirqs last  enabled at (3929): [<ffffffff8070f2b5>] mutex_lock_nested+0x285/0x310
hardirqs last disabled at (3928): [<ffffffff8070f089>] mutex_lock_nested+0x59/0x310
softirqs last  enabled at (3732): [<ffffffff8061f623>] sk_filter+0x83/0xe0
softirqs last disabled at (3730): [<ffffffff8061f5b6>] sk_filter+0x16/0xe0

other info that might help us debug this:
1 lock held by modprobe/8526:
 #0:  (testlock){--..}, at: [<ffffffffa0020055>] brd_init+0x55/0x216 [brd]

stack backtrace:
Pid: 8526, comm: modprobe Not tainted 2.6.28-rc6-00007-ged31348-dirty #26
Call Trace:
 [<ffffffff80265483>] print_usage_bug+0x193/0x1d0
 [<ffffffff80266530>] mark_lock+0xaf0/0xca0
 [<ffffffff80266735>] mark_held_locks+0x55/0xc0
 [<ffffffffa0020000>] ? brd_init+0x0/0x216 [brd]
 [<ffffffff802667ca>] trace_reclaim_fs+0x2a/0x60
 [<ffffffff80285005>] __alloc_pages_internal+0x475/0x580
 [<ffffffff8070f29e>] ? mutex_lock_nested+0x26e/0x310
 [<ffffffffa0020000>] ? brd_init+0x0/0x216 [brd]
 [<ffffffffa002006a>] brd_init+0x6a/0x216 [brd]
 [<ffffffffa0020000>] ? brd_init+0x0/0x216 [brd]
 [<ffffffff8020903b>] _stext+0x3b/0x170
 [<ffffffff8070f8b9>] ? mutex_unlock+0x9/0x10
 [<ffffffff8070f83d>] ? __mutex_unlock_slowpath+0x10d/0x180
 [<ffffffff802669ec>] ? trace_hardirqs_on_caller+0x12c/0x190
 [<ffffffff80272ebf>] sys_init_module+0xaf/0x1e0
 [<ffffffff8020c3fb>] system_call_fastpath+0x16/0x1b

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-14 23:27:49 +01:00
..
Kconfig Remove obsolete CONFIG_RESOURCES_64BIT 2009-01-06 15:59:14 -08:00
Makefile shmem: unify regular and tiny shmem 2009-01-06 15:59:08 -08:00
allocpercpu.c mm/allocpercpu.c: make 4 functions static 2008-07-26 12:00:12 -07:00
backing-dev.c Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-01-06 17:10:04 -08:00
bootmem.c bootmem: print request details before BUG_ON(them) 2009-01-06 15:59:10 -08:00
bounce.c bounce: don't rely on a zeroed bio_vec list 2008-12-29 08:29:52 +01:00
dmapool.c dmapool: enable debugging for CONFIG_SLUB_DEBUG_ON too 2008-04-28 08:58:20 -07:00
fadvise.c [CVE-2009-0029] System call wrapper special cases 2009-01-14 14:15:18 +01:00
failslab.c SLUB: failslab support 2008-12-29 11:27:46 +02:00
filemap.c [CVE-2009-0029] System call wrapper special cases 2009-01-14 14:15:18 +01:00
filemap_xip.c badpage: remove vma from page_remove_rmap 2009-01-06 15:59:07 -08:00
fremap.c [CVE-2009-0029] System call wrappers part 13 2009-01-14 14:15:23 +01:00
highmem.c x86, pat: avoid highmem cache attribute aliasing 2008-08-15 17:22:57 +02:00
hugetlb.c mm: hugetlb: remove redundant `if' operation 2009-01-06 15:59:10 -08:00
internal.h mm: make get_user_pages() interruptible 2009-01-06 15:59:08 -08:00
maccess.c kgdb: fix optional arch functions and probe_kernel_* 2008-04-17 20:05:39 +02:00
madvise.c [CVE-2009-0029] System call wrappers part 14 2009-01-14 14:15:24 +01:00
memcontrol.c memcg: NULL pointer dereference at rmdir on some NUMA systems 2009-01-29 18:04:44 -08:00
memory.c do_wp_page: fix regression with execute in place 2009-02-05 12:56:48 -08:00
memory_hotplug.c mm: remove GFP_HIGHUSER_PAGECACHE 2009-01-06 15:59:01 -08:00
mempolicy.c [CVE-2009-0029] System call wrappers part 28 2009-01-14 14:15:30 +01:00
mempool.c spelling fixes: mm/ 2007-10-20 01:27:18 +02:00
migrate.c [CVE-2009-0029] System call wrappers part 28 2009-01-14 14:15:30 +01:00
mincore.c [CVE-2009-0029] System call wrappers part 14 2009-01-14 14:15:24 +01:00
mlock.c Manually revert "mlock: downgrade mmap sem while populating mlocked regions" 2009-02-01 11:00:16 -08:00
mm_init.c mm: mminit_loglevel cannot be __meminitdata anymore 2008-08-20 15:40:30 -07:00
mmap.c Stop playing silly games with the VM_ACCOUNT flag 2009-01-31 15:08:56 -08:00
mmu_notifier.c mmu-notifiers: core 2008-07-28 16:30:21 -07:00
mmzone.c mm: mark the correct zone as full when scanning zonelists 2008-09-13 14:41:52 -07:00
mprotect.c [CVE-2009-0029] System call wrappers part 13 2009-01-14 14:15:23 +01:00
mremap.c [CVE-2009-0029] System call wrappers part 13 2009-01-14 14:15:23 +01:00
msync.c [CVE-2009-0029] System call wrappers part 13 2009-01-14 14:15:23 +01:00
nommu.c uclinux: add process name to allocation error message 2009-01-27 16:42:03 +10:00
oom_kill.c memcg: avoid deadlock caused by race between oom and cpuset_attach 2009-01-08 08:31:09 -08:00
page-writeback.c write-back: fix nr_to_write counter 2009-02-03 16:59:08 -08:00
page_alloc.c lockdep: annotate reclaim context (__GFP_NOFS) 2009-02-14 23:27:49 +01:00
page_cgroup.c memcg: add mem_cgroup_disabled() 2009-01-08 08:31:05 -08:00
page_io.c mm: try_to_free_swap replaces remove_exclusive_swap_page 2009-01-06 15:59:03 -08:00
page_isolation.c memory hotplug: fix page_zone() calculation in test_pages_isolated() 2008-11-06 15:41:19 -08:00
pagewalk.c pagemap: pass mm into pagewalkers 2008-06-12 18:05:41 -07:00
pdflush.c cpumask: convert mm/ 2009-01-01 10:12:29 +10:30
prio_tree.c spelling fixes: mm/ 2007-10-20 01:27:18 +02:00
quicklist.c mm: size of quicklists shouldn't be proportional to the number of CPUs 2008-09-02 19:21:38 -07:00
readahead.c vmscan: split LRU lists into anon & file sets 2008-10-20 08:50:25 -07:00
rmap.c badpage: remove vma from page_remove_rmap 2009-01-06 15:59:07 -08:00
shmem.c Stop playing silly games with the VM_ACCOUNT flag 2009-01-31 15:08:56 -08:00
shmem_acl.c [PATCH] sanitize ->permission() prototype 2008-07-26 20:53:14 -04:00
slab.c lockdep: annotate reclaim context (__GFP_NOFS) 2009-02-14 23:27:49 +01:00
slob.c lockdep: annotate reclaim context (__GFP_NOFS) 2009-02-14 23:27:49 +01:00
slub.c lockdep: annotate reclaim context (__GFP_NOFS) 2009-02-14 23:27:49 +01:00
sparse-vmemmap.c vmemmap: warn about page_structs with remote distance 2008-11-06 15:41:19 -08:00
sparse.c meminit section warnings 2008-11-30 10:03:35 -08:00
swap.c memcg: add zone_reclaim_stat 2009-01-08 08:31:08 -08:00
swap_state.c memcg: mem+swap controller core 2009-01-08 08:31:05 -08:00
swapfile.c memcg: fix refcnt handling at swapoff 2009-01-29 18:04:43 -08:00
thrash.c
truncate.c mmap: handle mlocked pages during map, remap, unmap 2008-10-20 08:52:31 -07:00
util.c mm: Make generic weak get_user_pages_fast and EXPORT_GPL it 2008-08-12 17:52:53 +10:00
vmalloc.c revert "mm: vmalloc use mutex for purge" 2009-01-15 16:39:40 -08:00
vmscan.c lockdep: annotate reclaim context (__GFP_NOFS) 2009-02-14 23:27:49 +01:00
vmstat.c cpumask: convert mm/ 2009-01-01 10:12:29 +10:30