Currently lockdep will print the 1st circle detected if it
exists when acquiring a new (next) lock.
This patch prints the shortest path from the next lock to be
acquired to the previous held lock if a circle is found.
The patch still uses the current method to check circle, and
once the circle is found, breadth-first search algorithem is
used to compute the shortest path from the next lock to the
previous lock in the forward lock dependency graph.
Printing the shortest path will shorten the dependency chain,
and make troubleshooting for possible circular locking easier.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1246201486-7308-2-git-send-email-tom.leiming@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
genirq: Fix UP compile failure caused by irq_thread_check_affinity
* 'lockdep-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/peterz/linux-2.6-lockdep:
lockdep: Fix lockdep annotation for pipe_double_lock()
Since genirq: Delegate irq affinity setting to the irq thread
(591d2fb02e) compilation with
CONFIG_SMP=n fails with following error:
/usr/src/linux-2.6/kernel/irq/manage.c:
In function 'irq_thread_check_affinity':
/usr/src/linux-2.6/kernel/irq/manage.c:475:
error: 'struct irq_desc' has no member named 'affinity'
make[4]: *** [kernel/irq/manage.o] Error 1
That commit adds a new function irq_thread_check_affinity() which
uses struct irq_desc.affinity which is only available for CONFIG_SMP=y.
Move that function under #ifdef CONFIG_SMP.
[ tglx@brownpaperbag: compile and boot tested on UP and SMP ]
Signed-off-by: Bruno Premont <bonbons@linux-vserver.org>
LKML-Reference: <20090722222232.2eb3e1c4@neptune.home>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The presumed use of the pipe_double_lock() routine is to lock 2 locks in
a deadlock free way by ordering the locks by their address. However it
fails to keep the specified lock classes in order and explicitly
annotates a deadlock.
Rectify this.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Miklos Szeredi <mszeredi@suse.cz>
LKML-Reference: <1248163763.15751.11098.camel@twins>
* 'perf-counters-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/peterz/linux-2.6-perf: (31 commits)
perf_counter tools: Give perf top inherit option
perf_counter tools: Fix vmlinux symbol generation breakage
perf_counter: Detect debugfs location
perf_counter: Add tracepoint support to perf list, perf stat
perf symbol: C++ demangling
perf: avoid structure size confusion by using a fixed size
perf_counter: Fix throttle/unthrottle event logging
perf_counter: Improve perf stat and perf record option parsing
perf_counter: PERF_SAMPLE_ID and inherited counters
perf_counter: Plug more stack leaks
perf: Fix stack data leak
perf_counter: Remove unused variables
perf_counter: Make call graph option consistent
perf_counter: Add perf record option to log addresses
perf_counter: Log vfork as a fork event
perf_counter: Synthesize VDSO mmap event
perf_counter: Make sure we dont leak kernel memory to userspace
perf_counter tools: Fix index boundary check
perf_counter: Fix the tracepoint channel to perfcounters
perf_counter, x86: Extend perf_counter Pentium M support
...
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: fix nr_uninterruptible accounting of frozen tasks really
sched: fix load average accounting vs. cpu hotplug
sched: Account for vruntime wrapping
* 'tj-block-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc:
virtio_blk: mark virtio_blk with __refdata to kill spurious section mismatch
block: sysfs fix mismatched queue_var_{store,show} in 64bit kernel
ataflop: adjust NULL test
block: fix failfast merge testing in elv_rq_merge_ok()
z2ram: Small cleanup for z2ram.c
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (37 commits)
sky2: Avoid races in sky2_down
drivers/net/mlx4: Adjust constant
drivers/net: Move a dereference below a NULL test
drivers/net: Move a dereference below a NULL test
connector: maintainer/mail update.
USB host CDC Phonet network interface driver
macsonic, jazzsonic: fix oops on module unload
macsonic: move probe function to .devinit.text
can: switch carrier on if device was stopped while in bus-off state
can: restart device even if dev_alloc_skb() fails
can: sja1000: remove duplicated includes
New device ID for sc92031 [1088:2031]
3c589_cs: re-initialize the multicast in the tc589_reset
Fix error return for setsockopt(SO_TIMESTAMPING)
netxen: fix thermal check and shutdown
netxen: fix deadlock on dev close
netxen: fix context deletion sequence
net: Micrel KS8851 SPI network driver
tcp: Use correct peer adr when copying MD5 keys
tcp: Fix MD5 signature checking on IPv4 mapped sockets
...
* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
NFSv4: Fix a problem whereby a buggy server can oops the kernel
NFSv4: Fix an NFSv4 mount regression
NFSv4: Fix an Oops in nfs4_free_lock_state
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
ALSA: ctxfi: Swapped SURROUND-SIDE channels on emu20k2
ALSA: ca0106 - Fix the max capture buffer size
ALSA: hda - Fix pin-setup for Sony VAIO with STAC9872 codecs
ALSA: hda - Add quirk for Gateway T6834c laptop
ALSA: OSS sequencer should be initialized after snd_seq_system_client_init
ALSA: sound/isa: convert nested spin_lock_irqsave to spin_lock
ALSA: hda_codec: Check for invalid zero connections
vmlinux meets the criteria for symbol adjustment, which breaks vmlinux generated symbols.
Fix this by exempting vmlinux. This is a bit fragile in that someone could change the
kernel dso's name, but currently that name is also hardwired.
Signed-off-by: Mike Galbraith <efault@gmx.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1248091298.18702.18.camel@marge.simson.net>
If "/sys/kernel/debug" is not a debugfs mount point, search for the debugfs
filesystem in /proc/mounts, but also allows the user to specify
'--debugfs-dir=blah' or set the environment variable: 'PERF_DEBUGFS_DIR'
Signed-off-by: Jason Baron <jbaron@redhat.com>
[ also made it probe "/debug" by default ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20090721181629.GA3094@redhat.com>
Ming Lei
Linus Torvalds
Bruno Premont
Peter Zijlstra
Arjan van de Ven
Mike Galbraith
Jason Baron