- 18 Jul, 2009 5 commits
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Anton Blanchard authored
perf record uses -g for logging call graph data but perf report uses -c to print call graph data. Be consistent and use -g everywhere for call graph data. Also update the help text to reflect the current default - fractal,0.5 Signed-off-by:
Anton Blanchard <anton@samba.org> Acked-by:
Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by:
Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090716104817.803604373@samba.org> Signed-off-by:
Ingo Molnar <mingo@elte.hu>
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Anton Blanchard authored
Add the -d or --data option to log event addresses (eg page faults). Signed-off-by:
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Anton Blanchard authored
Right now we don't output vfork events. Even though we should always see an exec after a vfork, we may get perfcounter samples between the vfork and exec. These samples can lead to some confusion when parsing perfcounter data. To keep things consistent we should always log a fork event. It will result in a little more log data, but is less confusing to trace parsing tools. Signed-off-by:
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Anton Blanchard authored
perf record synthesizes mmap events for the running process. Right now it just catches file mappings, but we can check for the vdso symbol and add that too. Signed-off-by:
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Anton Blanchard authored
There are a few places we are leaking tiny amounts of kernel memory to userspace. This happens when writing out strings because we always align the end to 64 bits. To avoid this we should always use an appropriately sized temporary buffer and ensure it is zeroed. Since d_path assembles the string from the end of the buffer backwards, we need to add 64 bits after the buffer to allow for alignment. We also need to copy arch_vma_name to the temporary buffer, because if we use it directly we may end up copying to userspace a number of bytes after the end of the string constant. Signed-off-by:
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- 13 Jul, 2009 2 commits
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Roel Kluin authored
Keep index within event_type_descriptors[] Signed-off-by:
Roel Kluin <roel.kluin@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <4A5A7F0B.4070106@gmail.com> Signed-off-by:
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Chris Wilson authored
Fix a missed rename in EVENT_PROFILE support so that it gets built and allows tracepoint tracing from the 'perf' tool. Fix a typo in the (never before built & enabled) portion in perf_counter.c as well, and update that code to the attr.config changes as well. Signed-off-by:
Chris Wilson <chris@chris-wilson.co.uk> Cc: Ben Gamari <bgamari.foss@gmail.com> Cc: Jason Baron <jbaron@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <1246869094-21237-1-git-send-email-chris@chris-wilson.co.uk> Signed-off-by:
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- 10 Jul, 2009 1 commit
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Anton Blanchard authored
The cache events contain '$' which will hit shell variable expansion. To avoid confusion change this to 'cache', ie L1-d$-loads becomes L1-dcache-loads. Signed-off-by:
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- 05 Jul, 2009 5 commits
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Frederic Weisbecker authored
The current callchain displays the overhead rates as absolute: relative to the total overhead. This patch provides relative overhead percentage, in which each branch of the callchain tree is a independant instrumentated object. This provides a 'fractal' view of the call-chain profile: each sub-graph looks like a profile in itself - relative to its parent. You can produce such output by using the "fractal" mode that you can abbreviate via f, fr, fra, frac, etc... ./perf report -s sym -c fractal Example: 8.46% [k] copy_user_generic_string | |--52.01%-- generic_file_aio_read | do_sync_read | vfs_read | | | |--97.20%-- sys_pread64 | | system_call_fastpath | | pread64 | | | --2.81%-- sys_read | system_call_fastpath | __read | |--39.85%-- generic_file_buffered_write | __generic_file_aio_write_nolock | generic_file_aio_write | do_sync_write | reiserfs_file_write | vfs_write | | | |--97.05%-- sys_pwrite64 | | system_call_fastpath | | __pwrite64 | | | --2.95%-- sys_write | system_call_fastpath | __write_nocancel [...] Signed-off-by: -
Frederic Weisbecker authored
The cumul hits are the number of hits of every childs of a node plus the hits of the current nodes, required for percentage computing of a branch. Theses numbers are calculated during the sorting of the branches of the callchain tree using a depth first postfix traversal, so that cumulative hits are propagated in the right order. But if we plan to implement percentages relative to the parent and not absolute percentages (relative to the whole overhead), we need to know the cumulative hits of the parent before computing the children because the relative minimum acceptable number of entries (ie: minimum rate against the cumulative hits from the parent) is the basis to filter the children against a given rate. Then we need to handle the cumul hits on the fly to prepare the implementation of relative overhead rates. Signed-off-by:
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Frederic Weisbecker authored
The default callchain parameters are set to use the flat mode and never filter any overhead threshold of backtrace. But flat mode is boring compared to graph mode. Also the number of callchains may be very high if none is filtered. Let's change this to set the graph view and a minimum overhead of 0.5% as default parameters. Reported-by:
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Frederic Weisbecker authored
If the user doesn't provide options to tune his callchain output (ie: if he uses -c without arguments) then the default value passed in the OPT_CALLBACK_DEFAULT() macro is used. But it's parsed later by strtok() which will replace comma separators to a zero. This may segfault as we are using a read-only string. Use a modifiable one instead, and also fix the "100%" default minimum threshold value by turning it into a 0 (output every callchains) as it was intended in the origin. Signed-off-by:
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Frederic Weisbecker authored
perf report segfaults while trying to handle callchains from a non callchain data file. Instead of a segfault, print a useful message to the user. Reported-by:
Jens Axboe <jens.axboe@oracle.com> Reported-by:
Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by:
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- 04 Jul, 2009 1 commit
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Eric Dumazet authored
Now atomic64_read() is light weight (no register pressure and small icache), we can inline it again. Also use "=&A" constraint instead of "+A" to avoid warning about unitialized 'res' variable. (gcc had to force 0 in eax/edx) $ size vmlinux.prev vmlinux.after text data bss dec hex filename 4908667 451676 1684868 7045211 6b805b vmlinux.prev 4908651 451676 1684868 7045195 6b804b vmlinux.after Signed-off-by:Eric Dumazet <eric.dumazet@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> LKML-Reference: <4A4E1AA2.30002@gmail.com> [ Also fix typo in atomic64_set() export ] Signed-off-by:
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- 03 Jul, 2009 15 commits
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Ingo Molnar authored
Linus noticed that the variable name 'old_val' is confusingly named in these functions - the correct naming is 'new_val'. Reported-by:
Linus Torvalds <torvalds@linux-foundation.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> LKML-Reference: <alpine.LFD.2.01.0907030942260.3210@localhost.localdomain> Signed-off-by:
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Ingo Molnar authored
Remove the read-first logic from atomic64_xchg() and simplify the loop. This function was the last user of __atomic64_read() - remove it. Also, change the 'real_val' assumption from the somewhat quirky 1ULL << 32 value to the (just as arbitrary, but simpler) value of 0. Reported-by:
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Ingo Molnar authored
atomic64_t primitives are used by a handful of drivers, so export the APIs consistently. These were inlined before. Also mark atomic64_32.o a core object, so that the symbols are available even if not linked to core kernel pieces. Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> LKML-Reference: <tip-05118ab8859492ac9ddda0154cf90e37b0a4a0b0@git.kernel.org> Signed-off-by: -
Eric Dumazet authored
Optimize atomic64_read() as a special open-coded cmpxchg8b variant. This generates nicer code: arch/x86/lib/atomic64_32.o: text data bss dec hex filename 435 0 0 435 1b3 atomic64_32.o.before 431 0 0 431 1af atomic64_32.o.after md5: bd8ab95e69c93518578bfaf0ea3be4d9 atomic64_32.o.before.asm 2bdfd4bd1f6b7b61b7fc127aef90ce3b atomic64_32.o.after.asm Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> LKML-Reference: <alpine.LFD.2.01.0907021653030.3210@localhost.localdomain> Signed-off-by: -
Paul Mackerras authored
Occasionally we get bugs where atomic_read or atomic_set are used on atomic64_t variables or vice versa. These bugs don't generate warnings on x86 because atomic_read and atomic_set are coded as macros rather than C functions, so we don't get any type-checking on their arguments; similarly for atomic64_read and atomic64_set in 64-bit kernels. This converts them to C functions so that the arguments are type-checked and bugs like this will get caught more easily. It also converts atomic_cmpxchg and atomic_xchg, and atomic64_cmpxchg and atomic64_xchg on 64-bit, so we get type-checking on their arguments too. Compiling a typical 64-bit x86 config, this generates no new warnings, and the vmlinux text is 86 bytes smaller. Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> LKML-Reference: <alpine.LFD.2.01.0907021653030.3210@localhost.localdomain> Signed-off-by: -
Ingo Molnar authored
Linus noticed that atomic64_xchg() uses atomic_read(), which happens to work because atomic_read() is a macro so the .counter value gets u64-read on 32-bit too - but this is really bogus and serious bugs are waiting to happen. Fix atomic64_xchg() to use __atomic64_read() instead. No code changed: arch/x86/lib/atomic64_32.o: text data bss dec hex filename 435 0 0 435 1b3 atomic64_32.o.before 435 0 0 435 1b3 atomic64_32.o.after md5: bd8ab95e69c93518578bfaf0ea3be4d9 atomic64_32.o.before.asm bd8ab95e69c93518578bfaf0ea3be4d9 atomic64_32.o.after.asm Reported-by: -
Ingo Molnar authored
Linus noticed that atomic64_xchg() uses atomic_read(), which happens to work because atomic_read() is a macro so the .counter value gets u64-read on 32-bit too - but this is really bogus and serious bugs are waiting to happen. Change atomic_read() to be a type-safe inline, and this exposes the atomic64 bogosity as well: arch/x86/lib/atomic64_32.c: In function ‘atomic64_xchg’: arch/x86/lib/atomic64_32.c:39: warning: passing argument 1 of ‘atomic_read’ from incompatible pointer type Reported-by:
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Ingo Molnar authored
cmpxchg8b is a huge instruction in terms of register footprint, we almost never want to inline it, not even within the same code module. GCC 4.3 still messes up for two functions, under-judging the true cost of this instruction - so annotate two key functions to reduce the bloat: arch/x86/lib/atomic64_32.o: text data bss dec hex filename 1763 0 0 1763 6e3 atomic64_32.o.before 435 0 0 435 1b3 atomic64_32.o.after Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> LKML-Reference: <alpine.LFD.2.01.0907021653030.3210@localhost.localdomain> Signed-off-by: -
Ingo Molnar authored
Linus noted (based on Eric Dumazet's numbers) that we would probably be better off not trying an atomic_read() in atomic64_add_return() but intead intentionally let the first cmpxchg8b fail - to get a cache-friendly 'give me ownership of this cacheline' transaction. That can then be followed by the real cmpxchg8b which sets the value local to the CPU. Reported-by:
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Eric Dumazet authored
Rewrite cmpxchg8b() to not use %edi register but a generic "+m" constraint, to increase compiler freedom in code generation and possibly better code. Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> LKML-Reference: <alpine.LFD.2.01.0907021653030.3210@localhost.localdomain> Signed-off-by: -
Eric Dumazet authored
Linus noticed that the 32-bit version of atomic64_read() was being overly complex with re-reading the value and doing a retry loop over that. Instead we can just rely on cmpxchg8b returning either the new value or returning the current value. We can use any 'old' value, which will be faster as it can be loaded via immediates. Using some value that is not equal to the real value in memory the instruction gets faster. This also has the advantage that the CPU could avoid dirtying the cacheline. Reported-by:
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Ingo Molnar authored
Linus noted that the atomic64_t primitives are all inlines currently which is crazy because these functions have a large register footprint anyway. Move them to a separate file: arch/x86/lib/atomic64_32.c Also, while at it, rename all uses of 'unsigned long long' to the much shorter u64. This makes the appearance of the prototypes a lot nicer - and it also uncovered a few bugs where (yet unused) API variants had 'long' as their return type instead of u64. [ More intrusive changes are not yet done in this patch. ] Reported-by:
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Eric Dumazet authored
Locked instructions on two cache lines at once are painful. If atomic64_t uses two cache lines, my test program is 10x slower. The chance for that is significant: 4/32 or 12.5%. Make sure an atomic64_t is 8 bytes aligned. Signed-off-by:
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Ingo Molnar authored
Certain versions of GCC dont see the initialization that is done here: builtin-report.c: In function ‘__cmd_report’: builtin-report.c:1038: warning: ‘syms’ may be used uninitialized in this function So annotate it with a NULL initialization. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <new-submission> Signed-off-by: -
Arnaldo Carvalho de Melo authored
Ingo Molnar wrote: > i just bisected a 'perf report' bug that would cause us to not > resolve all user-space symbols in a 'git gc' run to: > > f5812a7a is first bad commit > commit f5812a7a > Author: Arnaldo Carvalho de Melo <acme@redhat.com> > Date: Tue Jun 30 11:43:17 2009 -0300 > > perf_counter tools: Adjust only prelinked symbol's addresses Rename ->prelinked to ->adjust_symbols and making what was done only for prelinked libraries also to ET_EXEC binaries, such as /usr/bin/git: [acme@doppio pahole]$ readelf -h /usr/bin/git | grep Type Type: EXEC (Executable file) [acme@doppio pahole]$ And after installing the 'git-debuginfo' package, I get correct results: [acme@doppio linux-2.6-tip]$ perf report --sort comm,dso,symbol -d /usr/bin/git | head -20 # # (1139614 samples) # # Overhead Command Shared Object Symbol # ........ ................ ......................... ...... # 34.98% git /usr/bin/git [.] send_sideband 33.39% git /usr/bin/git [.] enter_repo 6.81% git /usr/bin/git [.] diff_opt_parse 4.95% git /usr/bin/git [.] is_repository_shallow 3.24% git /usr/bin/git [.] odb_mkstemp 1.39% git /usr/bin/git [.] output 1.34% git /usr/bin/git [.] xmmap 1.25% git /usr/bin/git [.] receive_pack_config 1.16% git /usr/bin/git [.] git_pathdup 0.90% git /usr/bin/git [.] read_object_with_reference 0.86% git /usr/bin/git [.] show_patch_diff 0.85% git /usr/bin/git 0x00000000095e2e 0.69% git /usr/bin/git [.] display [acme@doppio linux-2.6-tip]$ I'll check what are the last cases where we can't resolve symbols, like this 0x00000000095e2e later. And I guess this will fix the problems Mike were seeing too: [acme@doppio linux-2.6-tip]$ readelf -h ../build/perf/vmlinux | grep Type Type: EXEC (Executable file) [acme@doppio linux-2.6-tip]$ Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <new-submission> Signed-off-by:
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- 02 Jul, 2009 10 commits
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Frederic Weisbecker authored
This adds the use of colors to signal at a glance the important overhead thresholds in callchains hit rates. Signed-off-by:
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Frederic Weisbecker authored
Among perf annotate, perf report and perf top, we can find the common colored printing of percents according to the following rules: High overhead = > 5%, colored in red Mid overhead = > 0.5%, colored in green Low overhead = < 0.5%, default color Factorize these multiple checks in a single function named percent_color_fprintf() and also provide a get_percent_color() for sites which print percentages and other things at the same time. Signed-off-by: -
Frederic Weisbecker authored
Callchains output may become a burden on a trace because even rarely hit site are exposed. This can be too much information. Let the user set a threshold as a minimum percent of hits using the new pattern for the -c option: -c mode,min_percent Example: $ perf report -s sym -c flat,4 8.25% [k] copy_user_generic_string 4.19% copy_user_generic_string generic_file_aio_read do_sync_read vfs_read sys_pread64 system_call_fastpath pread64 5.39% [k] search_by_key 4.63% 0x00000000009e0a 2.36% [k] memcpy_c [...] $ perf report -s sym -c graph,2 8.25% [k] copy_user_generic_string | |--4.31%-- generic_file_aio_read | do_sync_read | vfs_read | | | --4.19%-- sys_pread64 | system_call_fastpath | pread64 | --3.24%-- generic_file_buffered_write __generic_file_aio_write_nolock generic_file_aio_write do_sync_write reiserfs_file_write vfs_write | --3.14%-- sys_pwrite64 system_call_fastpath __pwrite64 5.39% [k] search_by_key | --2.23%-- reiserfs_update_sd_size 4.63% 0x00000000009e0a 2.36% [k] memcpy_c [...] You can also omit it and it will default to 0. Signed-off-by: -
Frederic Weisbecker authored
Currently, the printing of callchains is done in a single vertical level, this is the "flat" mode: 8.25% [k] copy_user_generic_string 4.19% copy_user_generic_string generic_file_aio_read do_sync_read vfs_read sys_pread64 system_call_fastpath pread64 This patch introduces a new "graph" mode which provides a hierarchical output of factorized paths recursively sorted: 8.25% [k] copy_user_generic_string | |--4.31%-- generic_file_aio_read | do_sync_read | vfs_read | | | |--4.19%-- sys_pread64 | | system_call_fastpath | | pread64 | | | --0.12%-- sys_read | system_call_fastpath | __read | |--3.24%-- generic_file_buffered_write | __generic_file_aio_write_nolock | generic_file_aio_write | do_sync_write | reiserfs_file_write | vfs_write | | | |--3.14%-- sys_pwrite64 | | system_call_fastpath | | __pwrite64 | | | --0.10%-- sys_write [...] The command line has then changed. By providing the -c option, the callchain will output in the flat mode by default. But you can override it: perf report -c graph or perf report -c flat You can also pass the abreviated mode: perf report -c g or perf report -c gra will both make use of the graph mode. Signed-off-by: -
Frederic Weisbecker authored
There is no predefined macro to create an option that can have a custom value or a default one if none is given. This patch provides a new helper OPT_CALLBACK_DEFAULT() which defines such kind of option. For example, considering an option -c, we want to get the default value in the following cases: perf command -c -d perf command -d -c And the foo value when it's given: perf command -c foo -d perf command -d -c foo That's also why PARSE_OPT_LASTARG_DEFAULT is extended here to support default values whatever the position of the option, not only in the end. Should it now be renamed to PARSE_OPT_ARG_DEFAULT ? Signed-off-by: -
Frederic Weisbecker authored
Iterating through children of a node in the callchain tree shows something that may be quite confusing at a first glance. The head is the children field of the parent and the list nodes are in the brothers field of the children. This is because the childs are linked to the parent as a list of "brothers" using the "children" list of the parent as a head: --------------- | Parent (head) |------------------------------------- --------------- | | | children | | | ----------- ----------- | | 1st child |---brother---| 2nd child |---brother----- ----------- ----------- This makes the following strange pattern often occuring: list_for_each_entry(child, &parent->children, brothers) { // do something with children } Abstract it to chain_for_each_child() to factorize and simplify this pattern. Signed-off-by: -
Mike Galbraith authored
Add the -m/--modules option to perf report and perf annotate, which enables live module symbol/image loading. To be used with -k/--vmlinux. (Also give perf annotate a -P/--full-paths option.) Signed-off-by:
Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <1246514986.13293.48.camel@marge.simson.net> Signed-off-by:
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Mike Galbraith authored
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Mike Galbraith authored
Add infrastructure for module path discovery and section load addresses. Signed-off-by:
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Mike Galbraith authored
perf_counter tools: Make symbol loading consistently return number of loaded symbols. Signed-off-by:
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- 01 Jul, 2009 1 commit
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Frederic Weisbecker authored
Building builtin-stat.c reports the following errors: cc1: warnings being treated as errors builtin-stat.c: In function ‘run_perf_stat’: builtin-stat.c:242: erreur: ignoring return value of ‘read’, declared with attribute warn_unused_result builtin-stat.c:255: erreur: ignoring return value of ‘read’, declared with attribute warn_unused_result make: *** [builtin-stat.o] Erreur 1 This patch handles the possible pipe read failures. Signed-off-by:
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