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* Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds2010-10-27
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (50 commits) perf python scripting: Add futex-contention script perf python scripting: Fixup cut'n'paste error in sctop script perf scripting: Shut up 'perf record' final status perf record: Remove newline character from perror() argument perf python scripting: Support fedora 11 (audit 1.7.17) perf python scripting: Improve the syscalls-by-pid script perf python scripting: print the syscall name on sctop perf python scripting: Improve the syscalls-counts script perf python scripting: Improve the failed-syscalls-by-pid script kprobes: Remove redundant text_mutex lock in optimize x86/oprofile: Fix uninitialized variable use in debug printk tracing: Fix 'faild' -> 'failed' typo perf probe: Fix format specified for Dwarf_Off parameter perf trace: Fix detection of script extension perf trace: Use $PERF_EXEC_PATH in canned report scripts perf tools: Document event modifiers perf tools: Remove direct slang.h include perf_events: Fix for transaction recovery in group_sched_in() perf_events: Revert: Fix transaction recovery in group_sched_in() perf, x86: Use NUMA aware allocations for PEBS/BTS/DS allocations ...
| * Merge branch 'tip/perf/ringbuffer-2' of ↵Ingo Molnar2010-10-26
| |\ | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/urgent
| | * ring-buffer: Remove unused macro RB_TIMESTAMPS_PER_PAGESteven Rostedt2010-10-20
| | | | | | | | | | | | | | | | | | | | | With the binding of time extends to events we no longer need to use the macro RB_TIMESTAMPS_PER_PAGE. Remove it. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| | * ring-buffer: Micro-optimize with some strategic inliningSteven Rostedt2010-10-20
| | | | | | | | | | | | | | | | | | | | | By using inline and noinline, we are able to make the fast path of recording an event 4% faster. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| | * ring-buffer: Remove condition to add timestamp in fast pathSteven Rostedt2010-10-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's a condition to check if we should add a time extend or not in the fast path. But this condition is racey (in the sense that we can add a unnecessary time extend, but nothing that can break anything). We later check if the time or event time delta should be zero or have real data in it (not racey), making this first check redundant. This check may help save space once in a while, but really is not worth the hassle to try to save some space that happens at most 134 ms at a time. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| | * ring-buffer: Bind time extend and data events togetherSteven Rostedt2010-10-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the time between two timestamps is greater than 2^27 nanosecs (~134 ms) a time extend event is added that extends the time difference to 59 bits (~18 years). This is due to events only having a 27 bit field to store time. Currently this time extend is a separate event. We add it just before the event data that is being written to the buffer. But before the event data is committed, the event data can also be discarded (as with the case of filters). But because the time extend has already been committed, it will stay in the buffer. If lots of events are being filtered and no event is being written, then every 134ms a time extend can be added to the buffer without any data attached. To keep from filling the entire buffer with time extends, a time extend will never be the first event in a page because the page timestamp can be used. Time extends can only fill the rest of a page with some data at the beginning. This patch binds the time extend with the data. The difference here is that the time extend is not committed before the data is added. Instead, when a time extend is needed, the space reserved on the ring buffer is the time extend + the data event size. The time extend is added to the first part of the reserved block and the data is added to the second. The time extend event is passed back to the reserver, but since the reserver also uses a function to find the data portion of the reserved block, no changes to the ring buffer interface need to be made. When a commit is discarded, we now remove both the time extend and the event. With this approach no more than one time extend can be in the buffer in a row. Data must always follow a time extend. Thanks to Mathieu Desnoyers for suggesting this idea. Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| | * ring-buffer: Pass delta by value and not by referenceSteven Rostedt2010-10-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The delta between events is passed to the timestamp code by reference and the timestamp code will reset the value. But it can be reset from the caller. No need to pass it in by reference. By changing the call to pass by value, lets gcc optimize the code a bit more where it can store the delta in a register and not worry about updating the reference. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| | * ring-buffer: Pass timestamp by value and not by referenceSteven Rostedt2010-10-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The original code for the ring buffer had locations that modified the timestamp and that change was used by the callers. Now, the timestamp is not reused by the callers and there is no reason to pass it by reference. By changing the call to pass by value, lets gcc optimize the code a bit more where it can store the timestamp in a register and not worry about updating the reference. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| | * ring-buffer: Make write slow path out of lineSteven Rostedt2010-10-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Gcc inlines the slow path of the ring buffer write which can hurt performance. This patch simply forces the slow path function rb_move_tail() to always be a function. The ring_buffer_benchmark module with reader_disabled=1 shows that this patch changes the time to record an event from 135 ns to 132 ns. (3 ns or 2.22% improvement) Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bklLinus Torvalds2010-10-22
|\ \ \ | |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl: vfs: make no_llseek the default vfs: don't use BKL in default_llseek llseek: automatically add .llseek fop libfs: use generic_file_llseek for simple_attr mac80211: disallow seeks in minstrel debug code lirc: make chardev nonseekable viotape: use noop_llseek raw: use explicit llseek file operations ibmasmfs: use generic_file_llseek spufs: use llseek in all file operations arm/omap: use generic_file_llseek in iommu_debug lkdtm: use generic_file_llseek in debugfs net/wireless: use generic_file_llseek in debugfs drm: use noop_llseek
| * | llseek: automatically add .llseek fopArnd Bergmann2010-10-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
* | | Merge branch 'perf-core-for-linus' of ↵Linus Torvalds2010-10-21
|\ \ \ | |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (163 commits) tracing: Fix compile issue for trace_sched_wakeup.c [S390] hardirq: remove pointless header file includes [IA64] Move local_softirq_pending() definition perf, powerpc: Fix power_pmu_event_init to not use event->ctx ftrace: Remove recursion between recordmcount and scripts/mod/empty jump_label: Add COND_STMT(), reducer wrappery perf: Optimize sw events perf: Use jump_labels to optimize the scheduler hooks jump_label: Add atomic_t interface jump_label: Use more consistent naming perf, hw_breakpoint: Fix crash in hw_breakpoint creation perf: Find task before event alloc perf: Fix task refcount bugs perf: Fix group moving irq_work: Add generic hardirq context callbacks perf_events: Fix transaction recovery in group_sched_in() perf_events: Fix bogus AMD64 generic TLB events perf_events: Fix bogus context time tracking tracing: Remove parent recording in latency tracer graph options tracing: Use one prologue for the preempt irqs off tracer function tracers ...
| * | Merge branch 'tip/perf/core' of ↵Ingo Molnar2010-09-15
| |\| | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core
| * | ring-buffer: Place duplicate expression into a single functionSteven Rostedt2010-09-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While discussing the strictness of the 80 character limit on the Kernel Summit Discussion mailing list, I showed examples that I broke that limit slightly with some algorithms. In discussing with John Linville, what looked better, I realized that two of the 80 char breaking culprits were an identical expression. As a clean up, this patch moves the identical expression into its own helper function and that is used instead. As a side effect, the offending code is now under the 80 character limit. :-) This clean up code also changes the expression from (A - B) - C to A - (B + C) This makes the code look a little nicer too. Cc: John W. Linville <linville@tuxdriver.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ring-buffer: Fix typo of time extends per pageSteven Rostedt2010-10-12
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Time stamps for the ring buffer are created by the difference between two events. Each page of the ring buffer holds a full 64 bit timestamp. Each event has a 27 bit delta stamp from the last event. The unit of time is nanoseconds, so 27 bits can hold ~134 milliseconds. If two events happen more than 134 milliseconds apart, a time extend is inserted to add more bits for the delta. The time extend has 59 bits, which is good for ~18 years. Currently the time extend is committed separately from the event. If an event is discarded before it is committed, due to filtering, the time extend still exists. If all events are being filtered, then after ~134 milliseconds a new time extend will be added to the buffer. This can only happen till the end of the page. Since each page holds a full timestamp, there is no reason to add a time extend to the beginning of a page. Time extends can only fill a page that has actual data at the beginning, so there is no fear that time extends will fill more than a page without any data. When reading an event, a loop is made to skip over time extends since they are only used to maintain the time stamp and are never given to the caller. As a paranoid check to prevent the loop running forever, with the knowledge that time extends may only fill a page, a check is made that tests the iteration of the loop, and if the iteration is more than the number of time extends that can fit in a page a warning is printed and the ring buffer is disabled (all of ftrace is also disabled with it). There is another event type that is called a TIMESTAMP which can hold 64 bits of data in the theoretical case that two events happen 18 years apart. This code has not been implemented, but the name of this event exists, as well as the structure for it. The size of a TIMESTAMP is 16 bytes, where as a time extend is only 8 bytes. The macro used to calculate how many time extends can fit on a page used the TIMESTAMP size instead of the time extend size cutting the amount in half. The following test case can easily trigger the warning since we only need to have half the page filled with time extends to trigger the warning: # cd /sys/kernel/debug/tracing/ # echo function > current_tracer # echo 'common_pid < 0' > events/ftrace/function/filter # echo > trace # echo 1 > trace_marker # sleep 120 # cat trace Enabling the function tracer and then setting the filter to only trace functions where the process id is negative (no events), then clearing the trace buffer to ensure that we have nothing in the buffer, then write to trace_marker to add an event to the beginning of a page, sleep for 2 minutes (only 35 seconds is probably needed, but this guarantees the bug), and then finally reading the trace which will trigger the bug. This patch fixes the typo and prevents the false positive of that warning. Reported-by: Hans J. Koch <hjk@linutronix.de> Tested-by: Hans J. Koch <hjk@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Stable Kernel <stable@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | gcc-4.6: kernel/*: Fix unused but set warningsAndi Kleen2010-09-05
|/ | | | | | | | | | No real bugs I believe, just some dead code. Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: andi@firstfloor.org Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge branch 'tip/perf/urgent-3' of ↵Steven Rostedt2010-08-16
|\ | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into trace/tip/perf/urgent-4 Conflicts: kernel/trace/trace_events.c Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Fix ring_buffer_read_page reading out of page boundaryHuang Ying2010-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the configuration: CONFIG_DEBUG_PAGEALLOC=y and Shaohua's patch: [PATCH]x86: make spurious_fault check correct pte bit Function call graph trace with the following will trigger a page fault. # cd /sys/kernel/debug/tracing/ # echo function_graph > current_tracer # cat per_cpu/cpu1/trace_pipe_raw > /dev/null BUG: unable to handle kernel paging request at ffff880006e99000 IP: [<ffffffff81085572>] rb_event_length+0x1/0x3f PGD 1b19063 PUD 1b1d063 PMD 3f067 PTE 6e99160 Oops: 0000 [#1] SMP DEBUG_PAGEALLOC last sysfs file: /sys/devices/virtual/net/lo/operstate CPU 1 Modules linked in: Pid: 1982, comm: cat Not tainted 2.6.35-rc6-aes+ #300 /Bochs RIP: 0010:[<ffffffff81085572>] [<ffffffff81085572>] rb_event_length+0x1/0x3f RSP: 0018:ffff880006475e38 EFLAGS: 00010006 RAX: 0000000000000ff0 RBX: ffff88000786c630 RCX: 000000000000001d RDX: ffff880006e98000 RSI: 0000000000000ff0 RDI: ffff880006e99000 RBP: ffff880006475eb8 R08: 000000145d7008bd R09: 0000000000000000 R10: 0000000000008000 R11: ffffffff815d9336 R12: ffff880006d08000 R13: ffff880006e605d8 R14: 0000000000000000 R15: 0000000000000018 FS: 00007f2b83e456f0(0000) GS:ffff880002100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: ffff880006e99000 CR3: 00000000064a8000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process cat (pid: 1982, threadinfo ffff880006474000, task ffff880006e40770) Stack: ffff880006475eb8 ffffffff8108730f 0000000000000ff0 000000145d7008bd <0> ffff880006e98010 ffff880006d08010 0000000000000296 ffff88000786c640 <0> ffffffff81002956 0000000000000000 ffff8800071f4680 ffff8800071f4680 Call Trace: [<ffffffff8108730f>] ? ring_buffer_read_page+0x15a/0x24a [<ffffffff81002956>] ? return_to_handler+0x15/0x2f [<ffffffff8108a575>] tracing_buffers_read+0xb9/0x164 [<ffffffff810debfe>] vfs_read+0xaf/0x150 [<ffffffff81002941>] return_to_handler+0x0/0x2f [<ffffffff810248b0>] __bad_area_nosemaphore+0x17e/0x1a1 [<ffffffff81002941>] return_to_handler+0x0/0x2f [<ffffffff810248e6>] bad_area_nosemaphore+0x13/0x15 Code: 80 25 b2 16 b3 00 fe c9 c3 55 48 89 e5 f0 80 0d a4 16 b3 00 02 c9 c3 55 31 c0 48 89 e5 48 83 3d 94 16 b3 00 01 c9 0f 94 c0 c3 55 <8a> 0f 48 89 e5 83 e1 1f b8 08 00 00 00 0f b6 d1 83 fa 1e 74 27 RIP [<ffffffff81085572>] rb_event_length+0x1/0x3f RSP <ffff880006475e38> CR2: ffff880006e99000 ---[ end trace a6877bb92ccb36bb ]--- The root cause is that ring_buffer_read_page() may read out of page boundary, because the boundary checking is done after reading. This is fixed via doing boundary checking before reading. Reported-by: Shaohua Li <shaohua.li@intel.com> Cc: <stable@kernel.org> Signed-off-by: Huang Ying <ying.huang@intel.com> LKML-Reference: <1280297641.2771.307.camel@yhuang-dev> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | trace: Reorder struct ring_buffer_per_cpu to remove padding on 64bitRichard Kennedy2010-07-20
| | | | | | | | | | | | | | | | | | | | Reorder structure to remove 8 bytes of padding on 64 bit builds. This shrinks the size to 128 bytes so allowing allocation from a smaller slab & needed one fewer cache lines. Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk> LKML-Reference: <1269516456.2054.8.camel@localhost> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | Merge branch 'tip/perf/core-3' of ↵Ingo Molnar2010-06-08
|\ \ | |/ |/| | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core
| * tracing: Remove ftrace_preempt_disable/enableSteven Rostedt2010-06-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ftrace_preempt_disable/enable functions were to address a recursive race caused by the function tracer. The function tracer traces all functions which makes it easily susceptible to recursion. One area was preempt_enable(). This would call the scheduler and the schedulre would call the function tracer and loop. (So was it thought). The ftrace_preempt_disable/enable was made to protect against recursion inside the scheduler by storing the NEED_RESCHED flag. If it was set before the ftrace_preempt_disable() it would not call schedule on ftrace_preempt_enable(), thinking that if it was set before then it would have already scheduled unless it was already in the scheduler. This worked fine except in the case of SMP, where another task would set the NEED_RESCHED flag for a task on another CPU, and then kick off an IPI to trigger it. This could cause the NEED_RESCHED to be saved at ftrace_preempt_disable() but the IPI to arrive in the the preempt disabled section. The ftrace_preempt_enable() would not call the scheduler because the flag was already set before entring the section. This bug would cause a missed preemption check and cause lower latencies. Investigating further, I found that the recusion caused by the function tracer was not due to schedule(), but due to preempt_schedule(). Now that preempt_schedule is completely annotated with notrace, the recusion no longer is an issue. Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | ring-buffer: Move zeroing out excess in page to ring buffer codeSteven Rostedt2010-05-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the trace splice code zeros out the excess bytes in the page before sending it off to userspace. This is to make sure userspace is not getting anything it should not be when reading the pages, because the excess data was never initialized to zero before writing (for perfomance reasons). But the splice code has no business in doing this work, it should be done by the ring buffer. With the latest changes for recording lost events, the splice code gets it wrong anyway. Move the zeroing out of excess bytes into the ring buffer code. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | ring-buffer: Reset "real_end" when page is filledSteven Rostedt2010-05-25
|/ | | | | | | | | | | | | | | | | | The code to store the "lost events" requires knowing the real end of the page. Since the 'commit' includes the padding at the end of a page a "real_end" variable was used to keep track of the end not including the padding. If events were lost, the reader can place the count of events in the padded area if there is enough room. The bug this patch fixes is that when we fill the page we do not reset the real_end variable, and if the writer had wrapped a few times, the real_end would be incorrect. This patch simply resets the real_end if the page was filled. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ring-buffer: Wrap open-coded WARN_ONCEBorislav Petkov2010-05-04
| | | | | | | | Wrap open-coded WARN_ONCE functionality into the equivalent macro. Signed-off-by: Borislav Petkov <bp@alien8.de> LKML-Reference: <20100502060354.GA5281@liondog.tnic> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ring-buffer: Make non-consuming read less expensive with lots of cpus.David Miller2010-04-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When performing a non-consuming read, a synchronize_sched() is performed once for every cpu which is actively tracing. This is very expensive, and can make it take several seconds to open up the 'trace' file with lots of cpus. Only one synchronize_sched() call is actually necessary. What is desired is for all cpus to see the disabling state change. So we transform the existing sequence: for_each_cpu() { ring_buffer_read_start(); } where each ring_buffer_start() call performs a synchronize_sched(), into the following: for_each_cpu() { ring_buffer_read_prepare(); } ring_buffer_read_prepare_sync(); for_each_cpu() { ring_buffer_read_start(); } wherein only the single ring_buffer_read_prepare_sync() call needs to do the synchronize_sched(). The first phase, via ring_buffer_read_prepare(), allocates the 'iter' memory and increments ->record_disabled. In the second phase, ring_buffer_read_prepare_sync() makes sure this ->record_disabled state is visible fully to all cpus. And in the final third phase, the ring_buffer_read_start() calls reset the 'iter' objects allocated in the first phase since we now know that none of the cpus are adding trace entries any more. This makes openning the 'trace' file nearly instantaneous on a sparc64 Niagara2 box with 128 cpus tracing. Signed-off-by: David S. Miller <davem@davemloft.net> LKML-Reference: <20100420.154711.11246950.davem@davemloft.net> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* Merge branch 'linus' into tracing/coreIngo Molnar2010-04-08
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: include/linux/module.h kernel/module.c Semantic conflict: include/trace/events/module.h Merge reason: Resolve the conflict with upstream commit 5fbfb18 ("Fix up possibly racy module refcounting") Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * Merge branch 'master' into export-slabhTejun Heo2010-04-04
| |\
| | * ring-buffer: Add missing unlockJulia Lawall2010-03-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In some error handling cases the lock is not unlocked. The return is converted to a goto, to share the unlock at the end of the function. A simplified version of the semantic patch that finds this problem is as follows: (http://coccinelle.lip6.fr/) // <smpl> @r exists@ expression E1; identifier f; @@ f (...) { <+... * spin_lock_irq (E1,...); ... when != E1 * return ...; ...+> } // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> LKML-Reference: <Pine.LNX.4.64.1003291736440.21896@ask.diku.dk> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-30
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* | ring-buffer: Add lost event count to end of sub bufferSteven Rostedt2010-03-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, binary readers of the ring buffer only know where events were lost, but not how many events were lost at that location. This information is available, but it would require adding another field to the sub buffer header to include it. But when a event can not fit at the end of a sub buffer, it is written to the next sub buffer. This means there is a good chance that the buffer may have room to hold this counter. If it does, write the counter at the end of the sub buffer and set another flag in the data size field that states that this information exists. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | ring-buffer: Add place holder recording of dropped eventsSteven Rostedt2010-03-31
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, when the ring buffer drops events, it does not record the fact that it did so. It does inform the writer that the event was dropped by returning a NULL event, but it does not put in any place holder where the event was dropped. This is not a trivial thing to add because the ring buffer mostly runs in overwrite (flight recorder) mode. That is, when the ring buffer is full, new data will overwrite old data. In a produce/consumer mode, where new data is simply dropped when the ring buffer is full, it is trivial to add the placeholder for dropped events. When there's more room to write new data, then a special event can be added to notify the reader about the dropped events. But in overwrite mode, any new write can overwrite events. A place holder can not be inserted into the ring buffer since there never may be room. A reader could also come in at anytime and miss the placeholder. Luckily, the way the ring buffer works, the read side can find out if events were lost or not, and how many events. Everytime a write takes place, if it overwrites the header page (the next read) it updates a "overrun" variable that keeps track of the number of lost events. When a reader swaps out a page from the ring buffer, it can record this number, perfom the swap, and then check to see if the number changed, and take the diff if it has, which would be the number of events dropped. This can be stored by the reader and returned to callers of the reader. Since the reader page swap will fail if the writer moved the head page since the time the reader page set up the swap, this gives room to record the overruns without worrying about races. If the reader sets up the pages, records the overrun, than performs the swap, if the swap succeeds, then the overrun variable has not been updated since the setup before the swap. For binary readers of the ring buffer, a flag is set in the header of each sub page (sub buffer) of the ring buffer. This flag is embedded in the size field of the data on the sub buffer, in the 31st bit (the size can be 32 or 64 bits depending on the architecture), but only 27 bits needs to be used for the actual size (less actually). We could add a new field in the sub buffer header to also record the number of events dropped since the last read, but this will change the format of the binary ring buffer a bit too much. Perhaps this change can be made if the information on the number of events dropped is considered important enough. Note, the notification of dropped events is only used by consuming reads or peeking at the ring buffer. Iterating over the ring buffer does not keep this information because the necessary data is only available when a page swap is made, and the iterator does not swap out pages. Cc: Robert Richter <robert.richter@amd.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: "Luis Claudio R. Goncalves" <lclaudio@uudg.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ring-buffer: Do 8 byte alignment for 64 bit that can not handle 4 byte alignSteven Rostedt2010-03-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ring buffer uses 4 byte alignment while recording events into the buffer, even on 64bit machines. This saves space when there are lots of events being recorded at 4 byte boundaries. The ring buffer has a zero copy method to write into the buffer, with the reserving of space and then committing it. This may cause problems when writing an 8 byte word into a 4 byte alignment (not 8). For x86 and PPC this is not an issue, but on some architectures this would cause an out-of-alignment exception. This patch uses CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS to determine if it is OK to use 4 byte alignments on 64 bit machines. If it is not, it forces the ring buffer event header to be 8 bytes and not 4, and will align the length of the data to be 8 byte aligned. This keeps the data payload at 8 byte alignments and will allow these machines to run without issue. The trick to this is that the header can be either 4 bytes or 8 bytes depending on the length of the data payload. The 4 byte header has a length field that supports up to 112 bytes. If the length of the data is more than 112, the length field is set to zero, and the actual length is stored in the next 4 bytes after the header. When CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS is not set, the code forces zero in the 4 byte header forcing the length to be stored in the 4 byte array, even with a small data load. It also forces the length of the data load to be 8 byte aligned. The combination of these two guarantee that the data is always at 8 byte alignment. Tested-by: Frederic Weisbecker <fweisbec@gmail.com> (on sparc64) Reported-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* Merge branch 'tracing-fixes-for-linus' of ↵Linus Torvalds2010-03-13
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Do not record user stack trace from NMI context tracing: Disable buffer switching when starting or stopping trace tracing: Use same local variable when resetting the ring buffer function-graph: Init curr_ret_stack with ret_stack ring-buffer: Move disabled check into preempt disable section function-graph: Add tracing_thresh support to function_graph tracer tracing: Update the comm field in the right variable in update_max_tr function-graph: Use comment notation for func names of dangling '}' function-graph: Fix unused reference to ftrace_set_func() tracing: Fix warning in s_next of trace file ops tracing: Include irqflags headers from trace clock
| * ring-buffer: Move disabled check into preempt disable sectionLai Jiangshan2010-03-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ring buffer resizing and resetting relies on a schedule RCU action. The buffers are disabled, a synchronize_sched() is called and then the resize or reset takes place. But this only works if the disabling of the buffers are within the preempt disabled section, otherwise a window exists that the buffers can be written to while a reset or resize takes place. Cc: stable@kernel.org Reported-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4B949E43.2010906@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | Merge branch 'for-next' into for-linusJiri Kosina2010-03-08
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: Documentation/filesystems/proc.txt arch/arm/mach-u300/include/mach/debug-macro.S drivers/net/qlge/qlge_ethtool.c drivers/net/qlge/qlge_main.c drivers/net/typhoon.c
| * | Fix misspellings of "truly" in comments.Adam Buchbinder2010-02-04
| |/ | | | | | | | | | | | | Some comments misspell "truly"; this fixes them. No code changes. Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* | Merge branch 'master' into percpuTejun Heo2010-02-02
|\|
| * ring-buffer: Check for end of page in iteratorSteven Rostedt2010-01-26
| | | | | | | | | | | | | | | | | | | | | | | | | | If the iterator comes to an empty page for some reason, or if the page is emptied by a consuming read. The iterator code currently does not check if the iterator is pass the contents, and may return a false entry. This patch adds a check to the ring buffer iterator to test if the current page has been completely read and sets the iterator to the next page if necessary. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ring-buffer: Check if ring buffer iterator has stale dataSteven Rostedt2010-01-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Usually reads of the ring buffer is performed by a single task. There are two types of reads from the ring buffer. One is a consuming read which will consume the entry that was read and the next read will be the entry that follows. The other is an iterator that will let the user read the contents of the ring buffer without modifying it. When an iterator is allocated, writes to the ring buffer are disabled to protect the iterator. The problem exists when consuming reads happen while an iterator is allocated. Specifically, the kind of read that swaps out an entire page (used by splice) and replaces it with a new read. If the iterator is on the page that is swapped out, then the next read may read from this swapped out page and return garbage. This patch adds a check when reading the iterator to make sure that the iterator contents are still valid. If a consuming read has taken place, the iterator is reset. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ring-buffer: Add rb_list_head() wrapper around new reader page next fieldSteven Rostedt2010-01-06
| | | | | | | | | | | | | | | | | | | | | | | | | | If the very unlikely case happens where the writer moves the head by one between where the head page is read and where the new reader page is assigned _and_ the writer then writes and wraps the entire ring buffer so that the head page is back to what was originally read as the head page, the page to be swapped will have a corrupted next pointer. Simple solution is to wrap the assignment of the next pointer with a rb_list_head(). Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ring-buffer: Wrap a list.next reference with rb_list_head()David Sharp2010-01-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reference at the end of rb_get_reader_page() was causing off-by-one writes to the prev pointer of the page after the reader page when that page is the head page, and therefore the reader page has the RB_PAGE_HEAD flag in its list.next pointer. This eventually results in a GPF in a subsequent call to rb_set_head_page() (usually from rb_get_reader_page()) when that prev pointer is dereferenced. The dereferenced register would characteristically have an address that appears shifted left by one byte (eg, ffxxxxxxxxxxxxyy instead of ffffxxxxxxxxxxxx) due to being written at an address one byte too high. Signed-off-by: David Sharp <dhsharp@google.com> LKML-Reference: <1262826727-9090-1-git-send-email-dhsharp@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | local_t: Move local.h include to ringbuffer.c and ring_buffer_benchmark.cChristoph Lameter2010-01-05
|/ | | | | | | | | ringbuffer*.c are the last users of local.h. Remove the include from modules.h and add it to ringbuffer files. Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Tejun Heo <tj@kernel.org>
* Merge branch 'tracing-fixes-for-linus' of ↵Linus Torvalds2009-12-16
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Fix return of trace_dump_stack() ksym_tracer: Fix bad cast tracing/power: Remove two exports tracing: Change event->profile_count to be int type tracing: Simplify trace_option_write() tracing: Remove useless trace option tracing: Use seq file for trace_clock tracing: Use seq file for trace_options function-graph: Allow writing the same val to set_graph_function ftrace: Call trace_parser_clear() properly ftrace: Return EINVAL when writing invalid val to set_ftrace_filter tracing: Move a printk out of ftrace_raw_reg_event_foo() tracing: Pull up calls to trace_define_common_fields() tracing: Extract duplicate ftrace_raw_init_event_foo() ftrace.h: Use common pr_info fmt string tracing: Add stack trace to irqsoff tracer tracing: Add trace_dump_stack() ring-buffer: Move resize integrity check under reader lock ring-buffer: Use sync sched protection on ring buffer resizing tracing: Fix wrong usage of strstrip in trace_ksyms
| * ring-buffer: Move resize integrity check under reader lockSteven Rostedt2009-12-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While using an application that does splice on the ftrace ring buffer at start up, I triggered an integrity check failure. Looking into this, I discovered that resizing the buffer performs an integrity check after the buffer is resized. This check unfortunately is preformed after it releases the reader lock. If a reader is reading the buffer it may cause the integrity check to trigger a false failure. This patch simply moves the integrity checker under the protection of the ring buffer reader lock. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ring-buffer: Use sync sched protection on ring buffer resizingSteven Rostedt2009-12-10
| | | | | | | | | | | | | | | | | | | | | | | | | | There was a comment in the ring buffer code that says the calling layers should prevent tracing or reading of the ring buffer while resizing. I have discovered that the tracers do not honor this arrangement. This patch moves the disabling and synchronizing the ring buffer to a higher layer during resizing. This guarantees that no writes are occurring while the resize takes place. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | locking: Convert __raw_spin* functions to arch_spin*Thomas Gleixner2009-12-14
| | | | | | | | | | | | | | | | | | | | Name space cleanup. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: linux-arch@vger.kernel.org
* | locking: Rename __RAW_SPIN_LOCK_UNLOCKED to __ARCH_SPIN_LOCK_UNLOCKEDThomas Gleixner2009-12-14
| | | | | | | | | | | | | | | | | | | | Further name space cleanup. No functional change Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: linux-arch@vger.kernel.org
* | locking: Convert raw_spinlock to arch_spinlockThomas Gleixner2009-12-14
|/ | | | | | | | | | | | | | | | | | | The raw_spin* namespace was taken by lockdep for the architecture specific implementations. raw_spin_* would be the ideal name space for the spinlocks which are not converted to sleeping locks in preempt-rt. Linus suggested to convert the raw_ to arch_ locks and cleanup the name space instead of using an artifical name like core_spin, atomic_spin or whatever No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: linux-arch@vger.kernel.org
* Merge branch 'perf-core-for-linus' of ↵Linus Torvalds2009-12-05
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (470 commits) x86: Fix comments of register/stack access functions perf tools: Replace %m with %a in sscanf hw-breakpoints: Keep track of user disabled breakpoints tracing/syscalls: Make syscall events print callbacks static tracing: Add DEFINE_EVENT(), DEFINE_SINGLE_EVENT() support to docbook perf: Don't free perf_mmap_data until work has been done perf_event: Fix compile error perf tools: Fix _GNU_SOURCE macro related strndup() build error trace_syscalls: Remove unused syscall_name_to_nr() trace_syscalls: Simplify syscall profile trace_syscalls: Remove duplicate init_enter_##sname() trace_syscalls: Add syscall_nr field to struct syscall_metadata trace_syscalls: Remove enter_id exit_id trace_syscalls: Set event_enter_##sname->data to its metadata trace_syscalls: Remove unused event_syscall_enter and event_syscall_exit perf_event: Initialize data.period in perf_swevent_hrtimer() perf probe: Simplify event naming perf probe: Add --list option for listing current probe events perf probe: Add argv_split() from lib/argv_split.c perf probe: Move probe event utility functions to probe-event.c ...
| * Merge commit 'v2.6.32-rc7' into perf/coreIngo Molnar2009-11-15
| |\ | | | | | | | | | | | | | | | Merge reason: pick up perf fixlets Signed-off-by: Ingo Molnar <mingo@elte.hu>