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* oprofile: protect from not being in an IRQ contextPhil Carmody2010-05-031-2/+10
| | | | | | | | | | | | | | | | http://lkml.org/lkml/2010/4/27/285 Protect against dereferencing regs when it's NULL, and force a magic number into pc to prevent too deep processing. This approach permits the dropped samples to be tallied as invalid Instruction Pointer events. e.g. output from about 15mins at 10kHz sample rate: Nr. samples received: 2565380 Nr. samples lost invalid pc: 4 Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Signed-off-by: Robert Richter <robert.richter@amd.com>
* Merge commit 'tip/tracing/core' into oprofile/coreRobert Richter2010-04-231-1/+1
|\ | | | | | | | | | | | | Conflicts: drivers/oprofile/cpu_buffer.c Signed-off-by: Robert Richter <robert.richter@amd.com>
| * ring-buffer: Add place holder recording of dropped eventsSteven Rostedt2010-03-311-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | oprofile: remove double ring bufferingAndi Kleen2010-04-231-50/+13
|/ | | | | | | | | | | | | | | | | | oprofile used a double buffer scheme for its cpu event buffer to avoid races on reading with the old locked ring buffer. But that is obsolete now with the new ring buffer, so simply use a single buffer. This greatly simplifies the code and avoids a lot of sample drops on large runs, especially with call graph. Based on suggestions from Steven Rostedt For stable kernels from v2.6.32, but not earlier. Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: stable <stable@kernel.org> Signed-off-by: Robert Richter <robert.richter@amd.com>
* percpu: make percpu symbols in oprofile uniqueTejun Heo2009-10-291-10/+9
| | | | | | | | | | | | | | | | This patch updates percpu related symbols in oprofile such that percpu symbols are unique and don't clash with local symbols. This serves two purposes of decreasing the possibility of global percpu symbol collision and allowing dropping per_cpu__ prefix from percpu symbols. * drivers/oprofile/cpu_buffer.c: s/cpu_buffer/op_cpu_buffer/ Partly based on Rusty Russell's "alloc_percpu: rename percpu vars which cause name clashes" patch. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Robert Richter <robert.richter@amd.com> Cc: Rusty Russell <rusty@rustcorp.com.au>
* x86/oprofile: introduce oprofile_add_data64()Robert Richter2009-06-111-0/+15
| | | | | | | | | The IBS implemention writes 64 bit register values to the cpu buffer by writing two 32 values using oprofile_add_data(). This patch introduces oprofile_add_data64() to write a single 64 bit value to the buffer. Signed-off-by: Robert Richter <robert.richter@amd.com>
* oprofile: remove obselete include headersRobert Richter2009-06-111-1/+0
| | | | | | | | This became obsolete with this commit: 6dad828 oprofile: port to the new ring_buffer Signed-off-by: Robert Richter <robert.richter@amd.com>
* oprofile: fix cpu buffer sizeRobert Richter2009-05-071-2/+6
| | | | | | | | | | The unit of oprofile_cpu_buffer_size is in samples, but was allocated in bytes. This led to the allocation of too small cpu buffers. This patch recalculates the buffer size in bytes taking also the ring_buffer_event header size into account. Reported-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> Signed-off-by: Robert Richter <robert.richter@amd.com>
* ring_buffer: remove unused flags parameter, fixIngo Molnar2009-02-061-3/+2
| | | | | | Oprofile's ring-buffer use was not considered. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* oprofile: fix uninitialized use of struct op_entryRobert Richter2009-01-171-0/+5
| | | | | | | | | | | Impact: fix crash In case of losing samples struct op_entry could have been used uninitialized causing e.g. a wrong preemption count or NULL pointer access. This patch fixes this. Signed-off-by: Robert Richter <robert.richter@amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* oprofile: make new cpu buffer functions part of the apiRobert Richter2009-01-071-3/+14
| | | | | | | | | | | | This patch creates the new functions oprofile_write_reserve() oprofile_add_data() oprofile_write_commit() and makes them part of the oprofile api. Signed-off-by: Robert Richter <robert.richter@amd.com>
* oprofile: remove #ifdef CONFIG_OPROFILE_IBS in non-ibs codeRobert Richter2009-01-071-4/+0
| | | | | | | | The ifdefs can be removed since the code is no longer ibs specific and can be used for other purposes as well. IBS specific code is only in op_model_amd.c. Signed-off-by: Robert Richter <robert.richter@amd.com>
* oprofile: use new data sample format for ibsRobert Richter2009-01-071-16/+23
| | | | | | | | | | | | | The new ring buffer implementation allows the storage of samples with different size. This patch implements the usage of the new sample format to store ibs samples in the cpu buffer. Until now, writing to the cpu buffer could lead to incomplete sampling sequences since IBS samples were transfered in multiple samples. Due to a full buffer, data could be lost at any time. This can't happen any more since the complete data is reserved in advance and then stored in a single sample. Signed-off-by: Robert Richter <robert.richter@amd.com>
* oprofile: add op_cpu_buffer_add_data()Robert Richter2009-01-071-1/+1
| | | | | | | | This function can be used to attach data to a sample. It returns the remaining free buffer size that has been reserved with op_cpu_buffer_write_reserve(). Signed-off-by: Robert Richter <robert.richter@amd.com>
* oprofile: rework implementation of cpu buffer eventsRobert Richter2009-01-071-64/+75
| | | | | | | | | | | | | | | | | Special events such as task or context switches are marked with an escape code in the cpu buffer followed by an event code or a task identifier. There is one escape code per event. To make escape sequences also available for data samples the internal cpu buffer format must be changed. The current implementation does not allow the extension of event codes since this would lead to collisions with the task identifiers. To avoid this, this patch introduces an event mask that allows the storage of multiple events with one escape code. Now, task identifiers are stored in the data section of the sample. The implementation also allows the usage of custom data in a sample. As a side effect the new code is much more readable and easier to understand. Signed-off-by: Robert Richter <robert.richter@amd.com>
* oprofile: modify op_cpu_buffer_read_entry()Robert Richter2009-01-071-3/+11
| | | | | | This implements the support of samples with attached data. Signed-off-by: Robert Richter <robert.richter@amd.com>
* oprofile: add op_cpu_buffer_write_reserve()Robert Richter2009-01-071-13/+30
| | | | | | | | | | | | | This function prepares the cpu buffer to write a sample. Struct op_entry is used during operations on the ring buffer while struct op_sample contains the data that is stored in the ring buffer. Struct entry can be uninitialized. The function reserves a data array that is specified by size. Use op_cpu_buffer_write_commit() after preparing the sample. In case of errors a null pointer is returned, otherwise the pointer to the sample. Signed-off-by: Robert Richter <robert.richter@amd.com>
* oprofile: rename add_sample() in cpu_buffer.cRobert Richter2009-01-071-11/+11
| | | | | | | Rename the fucntion to op_add_sample() since there is a collision with another one with the same name in buffer_sync.c. Signed-off-by: Robert Richter <robert.richter@amd.com>
* oprofile: remove backtrace code for ibsRobert Richter2009-01-071-8/+2
| | | | | | | | This code is broken since a TRACE_BEGIN_CODE is never sent to the daemon. The data becomes corrupt since the backtrace is interpreted as ibs sample. Signed-off-by: Robert Richter <robert.richter@amd.com>
* oprofile: remove unused ibs macroRobert Richter2009-01-071-2/+0
| | | | Signed-off-by: Robert Richter <robert.richter@amd.com>
* oprofile: remove unused components in struct oprofile_cpu_bufferRobert Richter2009-01-071-2/+0
| | | | Signed-off-by: Robert Richter <robert.richter@amd.com>
* oprofile: simplify add_sample() in cpu_buffer.cRobert Richter2008-12-301-5/+1
| | | | Signed-off-by: Robert Richter <robert.richter@amd.com>
* oprofile: simplify oprofile_begin_trace()Robert Richter2008-12-291-5/+4
| | | | | | | | This patch removes the unused return parameter in oprofile_begin_trace(). Also, oprofile_begin_trace() and oprofile_end_trace() are inline now. Signed-off-by: Robert Richter <robert.richter@amd.com>
* oprofile: add inline function __oprofile_add_ext_sample()Robert Richter2008-12-291-3/+10
| | | | | | | | This patch adds the inline function __oprofile_add_ext_sample() to cpu_buffer.c and thus reduces overhead when calling oprofile_add_sample(). Signed-off-by: Robert Richter <robert.richter@amd.com>
* oprofile: reordering some code in cpu_buffer.cRobert Richter2008-12-291-10/+10
| | | | | | Reordering code to keep alloc/free functions together. Signed-off-by: Robert Richter <robert.richter@amd.com>
* oprofile: remove ring buffer inline functions in cpu_buffer.hRobert Richter2008-12-291-2/+46
| | | | | | | This patch moves ring buffer inline functions to cpu_buffer.c. Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Robert Richter <robert.richter@amd.com>
* oprofile: rename cpu buffer functionsRobert Richter2008-12-291-2/+2
| | | | | | | | This patch renames cpu buffer functions to something more oprofile specific names. Functions will be moved to the global name space. Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Robert Richter <robert.richter@amd.com>
* oprofile: rename kernel-wide identifiersRobert Richter2008-12-161-6/+6
| | | | | | | | This patch renames kernel-wide identifiers to something more oprofile specific names. Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Robert Richter <robert.richter@amd.com>
* oprofile: fix lost sample counterRobert Richter2008-12-101-30/+53
| | | | | | | | The number of lost samples could be greater than the number of received samples. This patches fixes this. The implementation introduces return values for add_sample() and add_code(). Signed-off-by: Robert Richter <robert.richter@amd.com>
* oprofile: remove nr_available_slots()Robert Richter2008-12-101-34/+0
| | | | | | | | | | | | | | | | This function is no longer available after the port to the new ring buffer. Its removal can lead to incomplete sampling sequences since IBS samples and backtraces are transfered in multiple samples. Due to a full buffer, samples could be lost any time. The userspace daemon has to live with such incomplete sampling sequences as long as the data within one sample is consistent. This will be fixed by changing the internal buffer data there all data of one IBS sample or a backtrace is packed in a single ring buffer entry. This is possible since the new ring buffer supports variable data size. Signed-off-by: Robert Richter <robert.richter@amd.com>
* oprofile: port to the new ring_bufferRobert Richter2008-12-101-15/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch replaces the current oprofile cpu buffer implementation with the ring buffer provided by the tracing framework. The motivation here is to leave the pain of implementing ring buffers to others. Oh, no, there are more advantages. Main reason is the support of different sample sizes that could be stored in the buffer. Use cases for this are IBS and Cell spu profiling. Using the new ring buffer ensures valid and complete samples and allows copying the cpu buffer stateless without knowing its content. Second it will use generic kernel API and also reduce code size. And hopefully, there are less bugs. Since the new tracing ring buffer implementation uses spin locks to protect the buffer during read/write access, it is difficult to use the buffer in an NMI handler. In this case, writing to the buffer by the NMI handler (x86) could occur also during critical sections when reading the buffer. To avoid this, there are 2 buffers for independent read and write access. Read access is in process context only, write access only in the NMI handler. If the read buffer runs empty, both buffers are swapped atomically. There is potentially a small window during swapping where the buffers are disabled and samples could be lost. Using 2 buffers is a little bit overhead, but the solution is clear and does not require changes in the ring buffer implementation. It can be changed to a single buffer solution when the ring buffer access is implemented as non-locking atomic code. The new buffer requires more size to store the same amount of samples because each sample includes an u32 header. Also, there is more code to execute for buffer access. Nonetheless, the buffer implementation is proven in the ftrace environment and worth to use also in oprofile. Patches that changes the internal IBS buffer usage will follow. Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Robert Richter <robert.richter@amd.com>
* oprofile: moving cpu_buffer_reset() to cpu_buffer.hRobert Richter2008-12-101-12/+0
| | | | | | This is in preparation for changes in the cpu buffer implementation. Signed-off-by: Robert Richter <robert.richter@amd.com>
* oprofile: adding cpu_buffer_write_commit()Robert Richter2008-12-101-17/+1
| | | | | | This is in preparation for changes in the cpu buffer implementation. Signed-off-by: Robert Richter <robert.richter@amd.com>
* oprofile: adding cpu buffer r/w access functionsRobert Richter2008-12-101-1/+1
| | | | | | This is in preparation for changes in the cpu buffer implementation. Signed-off-by: Robert Richter <robert.richter@amd.com>
* oprofile: whitspace changes onlyRobert Richter2008-12-101-2/+2
| | | | Signed-off-by: Robert Richter <robert.richter@amd.com>
* oprofile: comment cleanupRobert Richter2008-12-101-9/+16
| | | | | | This fixes the coding style of some comments. Signed-off-by: Robert Richter <robert.richter@amd.com>
* Merge branch 'for-linus' of ↵Linus Torvalds2008-10-231-52/+39
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile: (21 commits) OProfile: Fix buffer synchronization for IBS oprofile: hotplug cpu fix oprofile: fixing whitespaces in arch/x86/oprofile/* oprofile: fixing whitespaces in arch/x86/oprofile/* oprofile: fixing whitespaces in drivers/oprofile/* x86/oprofile: add the logic for enabling additional IBS bits x86/oprofile: reordering functions in nmi_int.c x86/oprofile: removing unused function parameter in add_ibs_begin() oprofile: more whitespace fixes oprofile: whitespace fixes OProfile: Rename IBS sysfs dir into "ibs_op" OProfile: Rework string handling in setup_ibs_files() OProfile: Rework oprofile_add_ibs_sample() function oprofile: discover counters for op ppro too oprofile: Implement Intel architectural perfmon support oprofile: Don't report Nehalem as core_2 oprofile: drop const in num counters field Revert "Oprofile Multiplexing Patch" x86, oprofile: BUG: using smp_processor_id() in preemptible code x86/oprofile: fix on_each_cpu build error ... Manually fixed trivial conflicts in drivers/oprofile/{cpu_buffer.c,event_buffer.h}
| * oprofile: hotplug cpu fixChris J Arges2008-10-171-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | This patch addresses problems when hotplugging cpus while profiling. Instead of allocating only online cpus, all possible cpu buffers are allocated, which allows cpus to be onlined during operation. If a cpu is offlined before profiling is shutdown wq_sync_buffer checks for this condition then cancels this work and does not sync this buffer. Signed-off-by: Chris J Arges <arges@linux.vnet.ibm.com> Signed-off-by: Robert Richter <robert.richter@amd.com>
| * oprofile: fixing whitespaces in drivers/oprofile/*Robert Richter2008-10-161-8/+8
| | | | | | | | Signed-off-by: Robert Richter <robert.richter@amd.com>
| * oprofile: more whitespace fixesRobert Richter2008-10-151-11/+11
| | | | | | | | Signed-off-by: Robert Richter <robert.richter@amd.com>
| * OProfile: Rework oprofile_add_ibs_sample() functionRobert Richter2008-10-151-33/+15
| | | | | | | | | | | | Code looks much more cleaner now. Signed-off-by: Robert Richter <robert.richter@amd.com>
| * Merge commit 'v2.6.27-rc8' into oprofileIngo Molnar2008-09-301-1/+3
| |\ | | | | | | | | | | | | | | | | | | Conflicts: arch/x86/oprofile/nmi_int.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | powerpc/oprofile: Fix mutex locking for cell spu-oprofileCarl Love2008-10-211-1/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The issue is the SPU code is not holding the kernel mutex lock while adding samples to the kernel buffer. This patch creates per SPU buffers to hold the data. Data is added to the buffers from in interrupt context. The data is periodically pushed to the kernel buffer via a new Oprofile function oprofile_put_buff(). The oprofile_put_buff() function is called via a work queue enabling the funtion to acquire the mutex lock. The existing user controls for adjusting the per CPU buffer size is used to control the size of the per SPU buffers. Similarly, overflows of the SPU buffers are reported by incrementing the per CPU buffer stats. This eliminates the need to have architecture specific controls for the per SPU buffers which is not acceptable to the OProfile user tool maintainer. The export of the oprofile add_event_entry() is removed as it is no longer needed given this patch. Note, this patch has not addressed the issue of indexing arrays by the spu number. This still needs to be fixed as the spu numbering is not guarenteed to be 0 to max_num_spus-1. Signed-off-by: Carl Love <carll@us.ibm.com> Signed-off-by: Maynard Johnson <maynardj@us.ibm.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Acked-by: Robert Richter <robert.richter@amd.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | | Merge branch 'linus' into oprofile-v2Ingo Molnar2008-10-131-1/+3
|\ \ \ | |/ / |/| / | |/ | | | | | | Conflicts: arch/x86/kernel/apic_32.c arch/x86/oprofile/nmi_int.c include/linux/pci_ids.h
| * powerpc/cell/oprofile: Avoid double vfree of profile bufferCarl Love2008-08-261-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | If an error occurs on opcontrol start, the event and per cpu buffers are released. If later opcontrol shutdown is called then the free function will be called again to free buffers that no longer exist. This results in a kernel oops. The following changes prevent the call to delete buffers that don't exist. Signed-off-by: Carl Love <carll@us.ibm.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Robert Richter <robert.richter@amd.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
* | oprofile: fix printk in cpu_buffer.cRobert Richter2008-07-261-1/+1
| | | | | | | | | | | | | | | | Signed-off-by: Robert Richter <robert.richter@amd.com> Cc: oprofile-list <oprofile-list@lists.sourceforge.net> Cc: Robert Richter <robert.richter@amd.com> Cc: Barry Kasindorf <barry.kasindorf@amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | x86/oprofile: add CONFIG_OPROFILE_IBS optionRobert Richter2008-07-261-0/+4
| | | | | | | | | | | | | | | | Signed-off-by: Robert Richter <robert.richter@amd.com> Cc: oprofile-list <oprofile-list@lists.sourceforge.net> Cc: Robert Richter <robert.richter@amd.com> Cc: Barry Kasindorf <barry.kasindorf@amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | x86/oprofile: add IBS support for AMD CPUs, IBS buffer handling routinesBarry Kasindorf2008-07-261-1/+67
|/ | | | | | | | | | This patchset supports the new profiling hardware available in the latest AMD CPUs in the oProfile driver. Signed-off-by: Barry Kasindorf <barry.kasindorf@amd.com> Signed-off-by: Robert Richter <robert.richter@amd.com> Cc: oprofile-list <oprofile-list@lists.sourceforge.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* oprofile: don't request cache line alignment for cpu_bufferEric Dumazet2008-05-141-1/+1
| | | | | | | | | | | | | | Alignment was previously requested because cpu_buffer was an [NR_CPUS] array, to avoid cache line sharing between CPUS. After commit 608dfddd845da5ab6accef70154c8910529699f7 (oprofile: change cpu_buffer from array to per_cpu variable ), we dont need to force an alignement anymore since cpu_buffer sits in per_cpu zone. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Cc: Mike Travis <travis@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* oprofile: change cpu_buffer from array to per_cpu variableMike Travis2008-04-281-8/+8
| | | | | | | | | | Change cpu_buffer from array to per_cpu variable in oprofile functions. [akpm@linux-foundation.org: coding-style fixes] Cc: Philippe Elie <phil.el@wanadoo.fr> Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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