linux/kernel/trace, branch v3.13

Merge tag 'trace-fixes-v3.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2013-12-20T17:32:30Z

Pull ftrace fix from Steven Rostedt: "This fixes a long standing bug in the ftrace profiler. The problem is that the profiler only initializes the online CPUs, and not possible CPUs. This causes issues if the user takes CPUs online or offline while the profiler is running. If we online a CPU after starting the profiler, we lose all the trace information on the CPU going online. If we offline a CPU after running a test and start a new test, it will not clear the old data from that CPU. This bug causes incorrect data to be reported to the user if they online or offline CPUs during the profiling" * tag 'trace-fixes-v3.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ftrace: Initialize the ftrace profiler for each possible cpu

ftrace: Initialize the ftrace profiler for each possible cpu

2013-12-16T15:53:46Z

Ftrace currently initializes only the online CPUs. This implementation has two problems: - If we online a CPU after we enable the function profile, and then run the test, we will lose the trace information on that CPU. Steps to reproduce: # echo 0 > /sys/devices/system/cpu/cpu1/online # cd /tracing/ # echo >> set_ftrace_filter # echo 1 > function_profile_enabled # echo 1 > /sys/devices/system/cpu/cpu1/online # run test - If we offline a CPU before we enable the function profile, we will not clear the trace information when we enable the function profile. It will trouble the users. Steps to reproduce: # cd /tracing/ # echo >> set_ftrace_filter # echo 1 > function_profile_enabled # run test # cat trace_stat/function* # echo 0 > /sys/devices/system/cpu/cpu1/online # echo 0 > function_profile_enabled # echo 1 > function_profile_enabled # cat trace_stat/function* # run test # cat trace_stat/function* So it is better that we initialize the ftrace profiler for each possible cpu every time we enable the function profile instead of just the online ones. Link: http://lkml.kernel.org/r/1387178401-10619-1-git-send-email-miaox@cn.fujitsu.com Cc: stable@vger.kernel.org # 2.6.31+ Signed-off-by: Miao Xie Signed-off-by: Steven Rostedt

Merge tag 'trace-fixes-3.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2013-12-06T16:34:16Z

Pull tracing fix from Steven Rostedt: "A regression showed up that there's a large delay when enabling all events. This was prevalent when FTRACE_SELFTEST was enabled which enables all events several times, and caused the system bootup to pause for over a minute. This was tracked down to an addition of a synchronize_sched() performed when system call tracepoints are unregistered. The synchronize_sched() is needed between the unregistering of the system call tracepoint and a deletion of a tracing instance buffer. But placing the synchronize_sched() in the unreg of *every* system call tracepoint is a bit overboard. A single synchronize_sched() before the deletion of the instance is sufficient" * tag 'trace-fixes-3.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Only run synchronize_sched() at instance deletion time

tracing: Only run synchronize_sched() at instance deletion time

2013-12-05T19:22:30Z

It has been reported that boot up with FTRACE_SELFTEST enabled can take a very long time. There can be stalls of over a minute. This was tracked down to the synchronize_sched() called when a system call event is disabled. As the self tests enable and disable thousands of events, this makes the synchronize_sched() get called thousands of times. The synchornize_sched() was added with d562aff93bfb53 "tracing: Add support for SOFT_DISABLE to syscall events" which caused this regression (added in 3.13-rc1). The synchronize_sched() is to protect against the events being accessed when a tracer instance is being deleted. When an instance is being deleted all the events associated to it are unregistered. The synchronize_sched() makes sure that no more users are running when it finishes. Instead of calling synchronize_sched() for all syscall events, we only need to call it once, after the events are unregistered and before the instance is deleted. The event_mutex is held during this action to prevent new users from enabling events. Link: http://lkml.kernel.org/r/20131203124120.427b9661@gandalf.local.home Reported-by: Petr Mladek Acked-by: Tom Zanussi Acked-by: Petr Mladek Tested-by: Petr Mladek Signed-off-by: Steven Rostedt

Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2013-12-02T18:13:09Z

Pull perf fixes from Ingo Molnar: "Misc kernel and tooling fixes" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tools lib traceevent: Fix conversion of pointer to integer of different size perf/trace: Properly use u64 to hold event_id perf: Remove fragile swevent hlist optimization ftrace, perf: Avoid infinite event generation loop tools lib traceevent: Fix use of multiple options in processing field perf header: Fix possible memory leaks in process_group_desc() perf header: Fix bogus group name perf tools: Tag thread comm as overriden

ftrace: Fix function graph with loading of modules

2013-11-26T15:36:50Z

Commit 8c4f3c3fa9681 "ftrace: Check module functions being traced on reload" fixed module loading and unloading with respect to function tracing, but it missed the function graph tracer. If you perform the following # cd /sys/kernel/debug/tracing # echo function_graph > current_tracer # modprobe nfsd # echo nop > current_tracer You'll get the following oops message: ------------[ cut here ]------------ WARNING: CPU: 2 PID: 2910 at /linux.git/kernel/trace/ftrace.c:1640 __ftrace_hash_rec_update.part.35+0x168/0x1b9() Modules linked in: nfsd exportfs nfs_acl lockd ipt_MASQUERADE sunrpc ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter ip6_tables uinput snd_hda_codec_idt CPU: 2 PID: 2910 Comm: bash Not tainted 3.13.0-rc1-test #7 Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./To be filled by O.E.M., BIOS SDBLI944.86P 05/08/2007 0000000000000668 ffff8800787efcf8 ffffffff814fe193 ffff88007d500000 0000000000000000 ffff8800787efd38 ffffffff8103b80a 0000000000000668 ffffffff810b2b9a ffffffff81a48370 0000000000000001 ffff880037aea000 Call Trace: [] dump_stack+0x4f/0x7c [] warn_slowpath_common+0x81/0x9b [] ? __ftrace_hash_rec_update.part.35+0x168/0x1b9 [] warn_slowpath_null+0x1a/0x1c [] __ftrace_hash_rec_update.part.35+0x168/0x1b9 [] ? __mutex_lock_slowpath+0x364/0x364 [] ftrace_shutdown+0xd7/0x12b [] unregister_ftrace_graph+0x49/0x78 [] graph_trace_reset+0xe/0x10 [] tracing_set_tracer+0xa7/0x26a [] tracing_set_trace_write+0x8b/0xbd [] ? ftrace_return_to_handler+0xb2/0xde [] ? __sb_end_write+0x5e/0x5e [] vfs_write+0xab/0xf6 [] ftrace_graph_caller+0x85/0x85 [] SyS_write+0x59/0x82 [] ftrace_graph_caller+0x85/0x85 [] system_call_fastpath+0x16/0x1b ---[ end trace 940358030751eafb ]--- The above mentioned commit didn't go far enough. Well, it covered the function tracer by adding checks in __register_ftrace_function(). The problem is that the function graph tracer circumvents that (for a slight efficiency gain when function graph trace is running with a function tracer. The gain was not worth this). The problem came with ftrace_startup() which should always be called after __register_ftrace_function(), if you want this bug to be completely fixed. Anyway, this solution moves __register_ftrace_function() inside of ftrace_startup() and removes the need to call them both. Reported-by: Dave Wysochanski Fixes: ed926f9b35cd ("ftrace: Use counters to enable functions to trace") Cc: stable@vger.kernel.org # 3.0+ Signed-off-by: Steven Rostedt

perf/trace: Properly use u64 to hold event_id

2013-11-19T15:57:44Z

The 64-bit attr.config value for perf trace events was being copied into an "int" before doing a comparison, meaning the top 32 bits were being truncated. As far as I can tell this didn't cause any errors, but it did mean it was possible to create valid aliases for all the tracepoint ids which I don't think was intended. (For example, 0xffffffff00000018 and 0x18 both enable the same tracepoint). Signed-off-by: Vince Weaver Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1311151236100.11932@vincent-weaver-1.um.maine.edu Signed-off-by: Ingo Molnar

ftrace, perf: Avoid infinite event generation loop

2013-11-19T15:57:40Z

Vince's perf-trinity fuzzer found yet another 'interesting' problem. When we sample the irq_work_exit tracepoint with period==1 (or PERF_SAMPLE_PERIOD) and we add an fasync SIGNAL handler we create an infinite event generation loop: ,-> | irq_work_exit() -> | trace_irq_work_exit() -> | ... | __perf_event_overflow() -> (due to fasync) | irq_work_queue() -> (irq_work_list must be empty) '--------- arch_irq_work_raise() Similar things can happen due to regular poll() wakeups if we exceed the ring-buffer wakeup watermark, or have an event_limit. To avoid this, dis-allow sampling this particular tracepoint. In order to achieve this, create a special perf_perm function pointer for each event and call this (when set) on trying to create a tracepoint perf event. [ roasted: use expr... to allow for ',' in your expression ] Reported-by: Vince Weaver Tested-by: Vince Weaver Signed-off-by: Peter Zijlstra Cc: Steven Rostedt Cc: Dave Jones Cc: Frederic Weisbecker Link: http://lkml.kernel.org/r/20131114152304.GC5364@laptop.programming.kicks-ass.net Signed-off-by: Ingo Molnar

Merge tag 'trace-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2013-11-16T20:23:18Z

Pull tracing update from Steven Rostedt: "This batch of changes is mostly clean ups and small bug fixes. The only real feature that was added this release is from Namhyung Kim, who introduced "set_graph_notrace" filter that lets you run the function graph tracer and not trace particular functions and their call chain. Tom Zanussi added some updates to the ftrace multibuffer tracing that made it more consistent with the top level tracing. One of the fixes for perf function tracing required an API change in RCU; the addition of "rcu_is_watching()". As Paul McKenney is pushing that change in this release too, he gave me a branch that included all the changes to get that working, and I pulled that into my tree in order to complete the perf function tracing fix" * tag 'trace-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Add rcu annotation for syscall trace descriptors tracing: Do not use signed enums with unsigned long long in fgragh output tracing: Remove unused function ftrace_off_permanent() tracing: Do not assign filp->private_data to freed memory tracing: Add helper function tracing_is_disabled() tracing: Open tracer when ftrace_dump_on_oops is used tracing: Add support for SOFT_DISABLE to syscall events tracing: Make register/unregister_ftrace_command __init tracing: Update event filters for multibuffer recordmcount.pl: Add support for __fentry__ ftrace: Have control op function callback only trace when RCU is watching rcu: Do not trace rcu_is_watching() functions ftrace/x86: skip over the breakpoint for ftrace caller trace/trace_stat: use rbtree postorder iteration helper instead of opencoding ftrace: Add set_graph_notrace filter ftrace: Narrow down the protected area of graph_lock ftrace: Introduce struct ftrace_graph_data ftrace: Get rid of ftrace_graph_filter_enabled tracing: Fix potential out-of-bounds in trace_get_user() tracing: Show more exact help information about snapshot

Merge branch 'for-3.13/core' of git://git.kernel.dk/linux-block

2013-11-14T03:08:14Z

Pull block IO core updates from Jens Axboe: "This is the pull request for the core changes in the block layer for 3.13. It contains: - The new blk-mq request interface. This is a new and more scalable queueing model that marries the best part of the request based interface we currently have (which is fully featured, but scales poorly) and the bio based "interface" which the new drivers for high IOPS devices end up using because it's much faster than the request based one. The bio interface has no block layer support, since it taps into the stack much earlier. This means that drivers end up having to implement a lot of functionality on their own, like tagging, timeout handling, requeue, etc. The blk-mq interface provides all these. Some drivers even provide a switch to select bio or rq and has code to handle both, since things like merging only works in the rq model and hence is faster for some workloads. This is a huge mess. Conversion of these drivers nets us a substantial code reduction. Initial results on converting SCSI to this model even shows an 8x improvement on single queue devices. So while the model was intended to work on the newer multiqueue devices, it has substantial improvements for "classic" hardware as well. This code has gone through extensive testing and development, it's now ready to go. A pull request is coming to convert virtio-blk to this model will be will be coming as well, with more drivers scheduled for 3.14 conversion. - Two blktrace fixes from Jan and Chen Gang. - A plug merge fix from Alireza Haghdoost. - Conversion of __get_cpu_var() from Christoph Lameter. - Fix for sector_div() with 64-bit divider from Geert Uytterhoeven. - A fix for a race between request completion and the timeout handling from Jeff Moyer. This is what caused the merge conflict with blk-mq/core, in case you are looking at that. - A dm stacking fix from Mike Snitzer. - A code consolidation fix and duplicated code removal from Kent Overstreet. - A handful of block bug fixes from Mikulas Patocka, fixing a loop crash and memory corruption on blk cg. - Elevator switch bug fix from Tomoki Sekiyama. A heads-up that I had to rebase this branch. Initially the immutable bio_vecs had been queued up for inclusion, but a week later, it became clear that it wasn't fully cooked yet. So the decision was made to pull this out and postpone it until 3.14. It was a straight forward rebase, just pruning out the immutable series and the later fixes of problems with it. The rest of the patches applied directly and no further changes were made" * 'for-3.13/core' of git://git.kernel.dk/linux-block: (31 commits) block: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO block: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO block: Do not call sector_div() with a 64-bit divisor kernel: trace: blktrace: remove redundent memcpy() in compat_blk_trace_setup() block: Consolidate duplicated bio_trim() implementations block: Use rw_copy_check_uvector() block: Enable sysfs nomerge control for I/O requests in the plug list block: properly stack underlying max_segment_size to DM device elevator: acquire q->sysfs_lock in elevator_change() elevator: Fix a race in elevator switching and md device initialization block: Replace __get_cpu_var uses bdi: test bdi_init failure block: fix a probe argument to blk_register_region loop: fix crash if blk_alloc_queue fails blk-core: Fix memory corruption if blkcg_init_queue fails block: fix race between request completion and timeout handling blktrace: Send BLK_TN_PROCESS events to all running traces blk-mq: don't disallow request merges for req->special being set blk-mq: mq plug list breakage blk-mq: fix for flush deadlock ...