aboutsummaryrefslogtreecommitdiff
AgeCommit message (Collapse)Author
2009-05-07Merge branch 'linus' into tracing/coreIngo Molnar
Merge reason: tracing/core was on a .30-rc1 base and was missing out on on a handful of tracing fixes present in .30-rc5-almost. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-07tracing/events: fix concurrent access to ftrace_events list, fixLi Zefan
In filter_add_subsystem_pred() we should release event_mutex before calling filter_free_subsystem_preds(), since both functions hold event_mutex. [ Impact: fix deadlock when writing invalid pred into subsystem filter ] Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: tzanussi@gmail.com Cc: a.p.zijlstra@chello.nl Cc: fweisbec@gmail.com Cc: rostedt@goodmis.org LKML-Reference: <4A028993.7020509@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-07tracing/filters: support for operator reserved characters in stringsFrederic Weisbecker
When we set a filter for an event, such as: echo "name == my_lock_name" > \ /debug/tracing/events/lockdep/lock_acquired/filter then the following order of token type is parsed: - space - operator - parentheses - operand Because the operators and parentheses have a higher precedence than the operand characters, which is normal, then we can't use any string containing such special characters: ()=<>!&| To get this support and also avoid ambiguous intepretation from the parser or the human, we can do it using double quotes so that we keep the usual languages habits. Then after this patch you can still declare string condition like before: echo name == myname But if you want to compare against a string containing an operator character, you can use double quotes: echo 'name == "&myname"' Don't forget to include the whole expression into single quotes or the double ones will be eaten by echo. [ Impact: support strings with special characters for tracing filters ] Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Zhaolei <zhaolei@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-05-07tracing/filters: support for filters of dynamic sized arraysFrederic Weisbecker
Currently the filtering infrastructure supports well the numeric types and fixed sized array types. But the recently added __string() field uses a specific indirect offset mechanism which requires a specific predicate. Until now it wasn't supported. This patch adds this support and implies very few changes, only a new predicate is needed, the management of this specific field can be done through the usual string helpers in the filtering infrastructure. [ Impact: support all kinds of strings in the tracing filters ] Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Zhaolei <zhaolei@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-05-06tracing: add hierarchical enabling of eventsSteven Rostedt
With the current event directory, you can only enable individual events. The file debugfs/tracing/set_event is used to be able to enable or disable several events at once. But that can still be awkward. This patch adds hierarchical enabling of events. That is, each directory in debugfs/tracing/events has an "enable" file. This file can enable or disable all events within the directory and below. # echo 1 > /debugfs/tracing/events/enable will enable all events. # echo 1 > /debugfs/tracing/events/sched/enable will enable all events in the sched subsystem. # echo 1 > /debugfs/tracing/events/enable # echo 0 > /debugfs/tracing/events/irq/enable will enable all events, but then disable just the irq subsystem events. When reading one of these enable files, there are four results: 0 - all events this file affects are disabled 1 - all events this file affects are enabled X - there is a mixture of events enabled and disabled ? - this file does not affect any event Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-05-06tracing: reset ring buffer when removing modules with eventsSteven Rostedt
Li Zefan found that there's a race using the event ids of events and modules. When a module is loaded, an event id is incremented. We only have 16 bits for event ids (65536) and there is a possible (but highly unlikely) race that we could load and unload a module that registers events so many times that the event id counter overflows. When it overflows, it then restarts and goes looking for available ids. An id is available if it was added by a module and released. The race is if you have one module add an id, and then is removed. Another module loaded can use that same event id. But if the old module still had events in the ring buffer, the new module's call back would get bogus data. At best (and most likely) the output would just be garbage. But if the module for some reason used pointers (not recommended) then this could potentially crash. The safest thing to do is just reset the ring buffer if a module that registered events is removed. [ Impact: prevent unpredictable results of event id overflows ] Reported-by: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <49FEAFD0.30106@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-05-06tracing: update sample with TRACE_INCLUDE_FILESteven Rostedt
When creating trace events for ftrace, the header file with the TRACE_EVENT macros must also have a macro called TRACE_SYSTEM. This macro describes the name of the system the TRACE_EVENTS are defined for. It also doubles as a way for the define_trace.h file to include the file that included it. For example: in irq.h #define TRACE_SYSTEM irq [...] #include <trace/define_trace.h> The define_trace will use TRACE_SYSTEM to include irq.h. But if the name of the trace system does not match the name of the trace header file, one can override it with: Which will change define_trace.h to inclued foo_trace.h instead of foo.h The sample comments this, but people that use the sample code will more likely use the code and not read the comments. This patch changes the sample code to use the TRACE_INCLUDE_FILE to better show developers how to use it. [ Impact: make sample less confusing to developers ] Reported-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-05-06ring-buffer: change test to be more latency friendlySteven Rostedt
The ring buffer benchmark/test runs a producer for 10 seconds. This is done with preemption and interrupts enabled. But if the kernel is not compiled with CONFIG_PREEMPT, it basically stops everything but interrupts for 10 seconds. Although this is just a test and is not for production, this attribute can be quite annoying. It can also spawn badness elsewhere. This patch solves the issues by calling "cond_resched" when the system is not compiled with CONFIG_PREEMPT. It also keeps track of the time spent to call cond_resched such that it does not go against the time calculations. That is, if the task schedules away, the time scheduled out is removed from the test data. Note, this only works for non PREEMPT because we do not know when the task is scheduled out if we have PREEMPT enabled. [ Impact: prevent test from stopping the world for 10 seconds ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-05-06ring-buffer: make moving the tail page a separate functionSteven Rostedt
Ingo Molnar thought the code would be cleaner if we used a function call instead of a goto for moving the tail page. After implementing this, it seems that gcc still inlines the result and the output is pretty much the same. Since this is considered a cleaner approach, might as well implement it. [ Impact: code clean up ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-05-06ring-buffer: check for failed allocation in ring buffer benchmarkSteven Rostedt
The result of the allocation of the ring buffer read page in the ring buffer bench mark does not check the return to see if a page was actually allocated. This patch fixes that. [ Impact: avoid NULL dereference ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-05-06ring-buffer: remove unneeded conditional in rb_reserve_nextSteven Rostedt
The code in __rb_reserve_next checks on page overflow if it is the original commiter and then resets the page back to the original setting. Although this is fine, and the code is correct, it is a bit fragil. Some experimental work I did breaks it easily. The better and more robust solution is to have all commiters that overflow the page, simply subtract what they added. [ Impact: more robust ring buffer account management ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-05-06tracing: small trave_events sample Makefile cleanupChristoph Hellwig
Use -I$(src) to add the current directory the include path. [ Impact: cleanup ] Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-06tracing: trace_output.c, fix false positive compiler warningJaswinder Singh Rajput
This compiler warning: CC kernel/trace/trace_output.o kernel/trace/trace_output.c: In function ‘register_ftrace_event’: kernel/trace/trace_output.c:544: warning: ‘list’ may be used uninitialized in this function Is wrong as 'list' is always initialized - but GCC (4.3.2) does not recognize this relationship properly. Work around the warning by initializing the variable to NULL. [ Impact: fix false positive compiler warning ] Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-06blktrace: from-sector redundant in trace_block_remapAlan D. Brunelle
Remove redundant from-sector parameter: it's /always/ the bio's sector passed in. [ Impact: cleanup ] Signed-off-by: Alan D. Brunelle <alan.brunelle@hp.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <49FF517C.7000503@hp.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-06blktrace: correct remap namesAlan D. Brunelle
This attempts to clarify names utilized during block I/O remap operations (partition, volume manager). It correctly matches up the /from/ information for both device & sector. This takes in the concept from Kosaki Motohiro and extends it to include better naming for the "device_from" field. [ Impact: cleanup ] Signed-off-by: Alan D. Brunelle <alan.brunelle@hp.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <49FF4FAE.3000301@hp.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-06tracepoint: trace_sched_migrate_task(): remove parameterMathieu Desnoyers
The orig_cpu parameter in trace_sched_migrate_task() is not necessary, it can be got by using task_cpu(p) in the probe. [ Impact: micro-optimization ] Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> [ modified from Mathieu's patch. The original patch is at: http://marc.info/?l=linux-kernel&m=123791201716239&w=2 ] Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Cc: fweisbec@gmail.com Cc: rostedt@goodmis.org Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: zhaolei@cn.fujitsu.com Cc: laijs@cn.fujitsu.com LKML-Reference: <49FFFDB7.1050402@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-06tracing/events: fix concurrent access to ftrace_events listLi Zefan
A module will add/remove its trace events when it gets loaded/unloaded, so the ftrace_events list is not "const", and concurrent access needs to be protected. This patch thus fixes races between loading/unloding modules and read 'available_events' or read/write 'set_event', etc. Below shows how to reproduce the race: # for ((; ;)) { cat /mnt/tracing/available_events; } > /dev/null & # for ((; ;)) { insmod trace-events-sample.ko; rmmod sample; } & After a while: BUG: unable to handle kernel paging request at 0010011c IP: [<c1080f27>] t_next+0x1b/0x2d ... Call Trace: [<c10c90e6>] ? seq_read+0x217/0x30d [<c10c8ecf>] ? seq_read+0x0/0x30d [<c10b4c19>] ? vfs_read+0x8f/0x136 [<c10b4fc3>] ? sys_read+0x40/0x65 [<c1002a68>] ? sysenter_do_call+0x12/0x36 [ Impact: fix races when concurrent accessing ftrace_events list ] Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <4A00F709.3080800@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-06tracing/events: fix memory leak when unloading moduleLi Zefan
When unloading a module, memory allocated by init_preds() and trace_define_field() is not freed. [ Impact: fix memory leak ] Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Tom Zanussi <tzanussi@gmail.com> LKML-Reference: <4A00F6E0.3040503@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-06tracing/events: make SAMPLE_TRACE_EVENTS default to nLi Zefan
Normally a config should be default to n. This patch also makes the sample module-only, like SAMPLE_MARKERS and SAMPLE_TRACEPOINTS. [ Impact: don't build trace event sample by default ] Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <4A00F6C0.8090803@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-06tracing/events: don't say hi when loading the trace event sampleLi Zefan
The sample is useful for testing, and I'm using it. But after loading the module, it keeps saying hi every 10 seconds, this may be disturbing. Also Steven said commenting out the "hi" helped in causing races. :) [ Impact: make testing a bit easier ] Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <4A00F6AD.2070008@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-06ring-buffer: add benchmark and testerSteven Rostedt
This patch adds code that can benchmark the ring buffer as well as test it. This code can be compiled into the kernel (not recommended) or as a module. A separate ring buffer is used to not interfer with other users, like ftrace. It creates a producer and a consumer (option to disable creation of the consumer) and will run for 10 seconds, then sleep for 10 seconds and then repeat. While running, the producer will write 10 byte loads into the ring buffer with just putting in the current CPU number. The reader will continually try to read the buffer. The reader will alternate from reading the buffer via event by event, or by full pages. The output is a pr_info, thus it will fill up the syslogs. Starting ring buffer hammer End ring buffer hammer Time: 9000349 (usecs) Overruns: 12578640 Read: 5358440 (by events) Entries: 0 Total: 17937080 Missed: 0 Hit: 17937080 Entries per millisec: 1993 501 ns per entry Sleeping for 10 secs Starting ring buffer hammer End ring buffer hammer Time: 9936350 (usecs) Overruns: 0 Read: 28146644 (by pages) Entries: 74 Total: 28146718 Missed: 0 Hit: 28146718 Entries per millisec: 2832 353 ns per entry Sleeping for 10 secs Time: is the time the test ran Overruns: the number of events that were overwritten and not read Read: the number of events read (either by pages or events) Entries: the number of entries left in the buffer (the by pages will only read full pages) Total: Entries + Read + Overruns Missed: the number of entries that failed to write Hit: the number of entries that were written The above example shows that it takes ~353 nanosecs per entry when there is a reader, reading by pages (and no overruns) The event by event reader slowed the producer down to 501 nanosecs. [ Impact: see how changes to the ring buffer affect stability and performance ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-05-05ring-buffer: move big if statement downSteven Rostedt
In the hot path of the ring buffer "__rb_reserve_next" there's a big if statement that does not even return back to the work flow. code; if (cross to next page) { [ lots of code ] return; } more code; The condition is even the unlikely path, although we do not denote it with an unlikely because gcc is fine with it. The condition is true when the write crosses a page boundary, and we need to start at a new page. Having this if statement makes it hard to read, but calling another function to do the work is also not appropriate, because we are using a lot of variables that were set before the if statement, and we do not want to send them as parameters. This patch changes it to a goto: code; if (cross to next page) goto next_page; more code; return; next_page: [ lots of code] This makes the code easier to understand, and a bit more obvious. The output from gcc is practically identical. For some reason, gcc decided to use different registers when I switched it to a goto. But other than that, the logic is the same. [ Impact: easier to read code ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-05-05Merge branch 'drm-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 * 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6: drm/r128: fix r128 ioremaps to use ioremap_wc. drm: cleanup properly in drm_get_dev() failure paths drm: clean the map list before destroying the hash table drm: remove unreachable code in drm_sysfs.c drm: add control node checks missing from kms merge drm/kms: don't try to shortcut drm mode set function drm/radeon: bump minor version for occlusion queries support
2009-05-05tracing: use proper export symbol for tracing apiSteven Rostedt
When adding the EXPORT_SYMBOL to some of the tracing API, I accidently used EXPORT_SYMBOL instead of EXPORT_SYMBOL_GPL. This patch fixes that mistake. [ Impact: export the tracing code only for GPL modules ] Reported-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-05-05ftrace: use .sched.text, not .text.sched in recordmcount.plTim Abbott
The only references in the kernel to the .text.sched section are in recordmcount.pl. Since the code it has is intended to be example code it should refer to real kernel sections. So change it to .sched.text instead. [ Impact: consistency in comments ] Signed-off-by: Tim Abbott <tabbott@mit.edu> LKML-Reference: <1241136371-10768-1-git-send-email-tabbott@mit.edu> Acked-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-05-06drm/r128: fix r128 ioremaps to use ioremap_wc.Dave Airlie
This should allow r128 to start working again since PAT changes. taken from F-11 kernel. Signed-off-by: Dave Airlie <airlied@redhat.com>
2009-05-05Merge branch 'release' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6 * 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6: [IA64] xen_domu_defconfig: fix build issues/warnings
2009-05-05Ignore madvise(MADV_WILLNEED) for hugetlbfs-backed regionsMel Gorman
madvise(MADV_WILLNEED) forces page cache readahead on a range of memory backed by a file. The assumption is made that the page required is order-0 and "normal" page cache. On hugetlbfs, this assumption is not true and order-0 pages are allocated and inserted into the hugetlbfs page cache. This leaks hugetlbfs page reservations and can cause BUGs to trigger related to corrupted page tables. This patch causes MADV_WILLNEED to be ignored for hugetlbfs-backed regions. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-05ring-buffer: disable writers when resetting buffersSteven Rostedt
As a precaution, it is best to disable writing to the ring buffers when reseting them. [ Impact: prevent weird things if write happens during reset ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-05-05ring-buffer: have read page swap increment counter with page entriesSteven Rostedt
In the swap page ring buffer code that is used by the ftrace splice code, we scan the page to increment the counter of entries read. With the number of entries already in the page we simply need to add it. [ Impact: speed up reading page from ring buffer ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-05-05Merge branch 'timers/urgent' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: clockevents: prevent endless loop in tick_handle_periodic()
2009-05-05Merge branch 'irq/urgent' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'irq/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: Revert "genirq: assert that irq handlers are indeed running in hardirq context"
2009-05-05Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: account system time properly
2009-05-05Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: kernel/posix-cpu-timers.c: fix sparse warning dma-debug: remove broken dma memory leak detection for 2.6.30 locking: Documentation: lockdep-design.txt, fix note of state bits
2009-05-05Merge branch 'tracing-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: tracing: x86, mmiotrace: fix range test tracing: fix ref count in splice pages
2009-05-05Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86: show number of core_siblings instead of thread_siblings in /proc/cpuinfo amd-iommu: fix iommu flag masks x86: initialize io_bitmap_base on 32bit x86: gettimeofday() vDSO: fix segfault when tv == NULL
2009-05-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-fixesLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-fixes: kbuild, modpost: fix unexpected non-allocatable warning with mips kbuild, modpost: fix "unexpected non-allocatable" warning with SUSE gcc kbuild, modpost: fix unexpected non-allocatable section when cross compiling
2009-05-05[IA64] xen_domu_defconfig: fix build issues/warningsJan Beulich
- drivers/xen/events.c did not compile - xen_setup_hook caused a modpost section warning - the use of u64 (instead of unsigned long long) together with a %llu in drivers/xen/balloon.c caused a compiler warning Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2009-05-05ring-buffer: record page entries in buffer page descriptorSteven Rostedt
Currently, when the ring buffer writer overflows the buffer and must write over non consumed data, we increment the overrun counter by reading the entries on the page we are about to overwrite. This reads the entries one by one. This is not very effecient. This patch adds another entry counter into each buffer page descriptor that keeps track of the number of entries on the page. Now on overwrite, the overrun counter simply needs to add the number of entries that is on the page it is about to overwrite. [ Impact: speed up of ring buffer in overwrite mode ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-05-05ring-buffer: convert cpu buffer entries to local_tSteven Rostedt
The entries counter in cpu buffer is not atomic. It can be updated by other interrupts or from another CPU (readers). But making entries into "atomic_t" causes an atomic operation that can hurt performance. Instead we convert it to a local_t that will increment a counter with a local CPU atomic operation (if the arch supports it). Instead of fighting with readers and overwrites that decrement the counter, I added a "read" counter. Every time a reader reads an entry it is incremented. We already have a overrun counter and with that, the entries counter and the read counter, we can calculate the total number of entries in the buffer with: (entries - overrun) - read As long as the total number of entries in the ring buffer is less than the word size, this will work. But since the entries counter was previously a long, this is no different than what we had before. Thanks to Andrew Morton for pointing out in the first version that atomic_t does not replace unsigned long. I switched to atomic_long_t even though it is signed. A negative count is most likely a bug. [ Impact: keep accurate count of cpu buffer entries ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-05-05tracing: export stats of ring buffers to userspaceSteven Rostedt
This patch adds stats to the ftrace ring buffers: # cat /debugfs/tracing/per_cpu/cpu0/stats entries: 42360 overrun: 30509326 commit overrun: 0 nmi dropped: 0 Where entries are the total number of data entries in the buffer. overrun is the number of entries not consumed and were overwritten by the writer. commit overrun is the number of entries dropped due to nested writers wrapping the buffer before the initial writer finished the commit. nmi dropped is the number of entries dropped due to the ring buffer lock being held when an nmi was going to write to the ring buffer. Note, this field will be meaningless and will go away when the ring buffer becomes lockless. [ Impact: let userspace know what is happening in the ring buffers ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-05-05ring-buffer: add counters for commit overrun and nmi dropped entriesSteven Rostedt
The WARN_ON in the ring buffer when a commit is preempted and the buffer is filled by preceding writes can happen in normal operations. The WARN_ON makes it look like a bug, not to mention, because it does not stop tracing and calls printk which can also recurse, this is prone to deadlock (the WARN_ON is not in a position to recurse). This patch removes the WARN_ON and replaces it with a counter that can be retrieved by a tracer. This counter is called commit_overrun. While at it, I added a nmi_dropped counter to count any time an NMI entry is dropped because the NMI could not take the spinlock. [ Impact: prevent deadlock by printing normal case warning ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-05-05ring-buffer: export symbolsSteven Rostedt
I'm adding a module to do a series of tests on the ring buffer as well as benchmarks. This module needs to have more of the ring buffer API exported. There's nothing wrong with reading the ring buffer from a module. [ Impact: allow modules to read pages from the ring buffer ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-05-05Merge branch 'i2c-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6Linus Torvalds
* 'i2c-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6: i2c-algo-pca: Let PCA9564 recover from unacked data byte (state 0x30) i2c-algo-bit: Fix timeout test i2c: Timeouts off by 1
2009-05-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (30 commits) e1000: fix virtualization bug bonding: fix alb mode locking regression Bluetooth: Fix issue with sysfs handling for connections usbnet: CDC EEM support (v5) tcp: Fix tcp_prequeue() to get correct rto_min value ehea: fix invalid pointer access ne2k-pci: Do not register device until initialized. Subject: [PATCH] br2684: restore net_dev initialization net: Only store high 16 bits of kernel generated filter priorities virtio_net: Fix function name typo virtio_net: Cleanup command queue scatterlist usage bonding: correct the cleanup in bond_create() virtio: add missing include to virtio_net.h smsc95xx: add support for LAN9512 and LAN9514 smsc95xx: configure LED outputs netconsole: take care of NETDEV_UNREGISTER event xt_socket: checks for the state of nf_conntrack bonding: bond_slave_info_query() fix cxgb3: fixing gcc 4.4 compiler warning: suggest parentheses around operand of ‘!’ netfilter: use likely() in xt_info_rdlock_bh() ...
2009-05-05Merge branch 'merge' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc * 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: powerpc: Fix setting of oprofile cpu type powerpc: Update MPC5xxx and Xilinx Virtex maintainer entries powerpc adjust oprofile_cpu_type version 3
2009-05-05Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: selinux: Fix send_sigiotask hook
2009-05-05Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs: net/9p: handle correctly interrupted 9P requests net/9p: return error when p9_client_stat fails net/9p: set correct stat size when sending Twstat messages
2009-05-05Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc: mvsdio: fix CONFIG_PM=y build mmci: fix crash with debug enabled sdhci: catch ADMA errors mmc: increase power up delay sdhci-pci: bad error handling in probe function mmc_block: be prepared for oversized requests
2009-05-05Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6: ASoC: Remove BROKEN from mpc5200 kconfig ASoC: TWL4030: Fix gain control for earpiece amplifier ALSA: pcm core - Avoid jiffies check for devices with BATCH flag ALSA: Add missing SNDRV_PCM_INFO_BATCH flag to some drivers ALSA: indigo-express: add missing 64KHz flags ASoC: Set the MPC5200 i2s driver to BROKEN status. ASoC: Fix logic in WM8350 master clocking check