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2009-08-16perf: Enable more compiler warningsIngo Molnar
Related to a shadowed variable bug fix Valdis Kletnieks noticed that perf does not get built with -Wshadow, which could have helped us avoid the bug. So enable -Wshadow and also enable the following warnings on perf builds, in addition to the already enabled -Wall -Wextra -std=gnu99 warnings: -Wcast-align -Wformat=2 -Wshadow -Winit-self -Wpacked -Wredundant-decls -Wstack-protector -Wstrict-aliasing=3 -Wswitch-default -Wswitch-enum -Wno-system-headers -Wundef -Wvolatile-register-var -Wwrite-strings -Wbad-function-cast -Wmissing-declarations -Wmissing-prototypes -Wnested-externs -Wold-style-definition -Wstrict-prototypes -Wdeclaration-after-statement And change/fix the perf code to build cleanly under GCC 4.3.2. The list of warnings enablement is rather arbitrary: it's based on my (quick) reading of the GCC manpages and trying them on perf. I categorized the warnings based on individually enabling them and looking whether they trigger something in the perf build. If i liked those warnings (i.e. if they trigger for something that arguably could be improved) i enabled the warning. If the warnings seemed to come from language laywers spamming the build with tons of nuisance warnings i generally kept them off. Most of the sign conversion related warnings were in this category. (A second patch enabling some of the sign warnings might be welcome - sign bugs can be nasty.) I also kept warnings that seem to make sense from their manpage description and which produced no actual warnings on our code base. These warnings might still be turned off if they end up being a nuisance. I also left out a few warnings that are not supported in older compilers. [ Note that these changes might break the build on older compilers i did not test, or on non-x86 architectures that produce different warnings, so more testing would be welcome. ] Reported-by: Valdis.Kletnieks@vt.edu 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: Ingo Molnar <mingo@elte.hu>
2009-08-09perf tools: callchain: Fix bad rounding of minimum rateFrederic Weisbecker
Sometimes we get callchain branches that have a rate under the limit given by the user. Say you launched: perf record -f -g -a ./hackbench 10 perf report -g fractal,10.0 And you got: 2.33% hackbench [kernel] [k] _spin_lock_irqsave | |--78.57%-- remove_wait_queue | poll_freewait | do_sys_poll | sys_poll | sysenter_dispatch | 0xf7ffa430 | 0x1ffadea3c | |--7.14%-- __up_read | up_read | do_page_fault | page_fault | 0xf7ffa430 | 0xa0df710000000a ... It is abnormal to get a 7.14% branch whereas we passed a 10% filter. The problem is that we round down the minimum threshold. This happens mostly when we have very low number of events. If the total amount of your branch is 4 and you have a subranch of 3 events, filtering to 90% will be computed like follows: limit = 4 * 0.9; The result is about 3.6, but the cast to integer will round down to 3. It means that our filter is actually of 75% We must then explicitly round up the minimum threshold. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: acme@redhat.com Cc: peterz@infradead.org Cc: efault@gmx.de LKML-Reference: <20090809024235.GA10146@nowhere> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-09perf tools: callchain: Fix spurious 'perf report' warnings: ignore empty ↵Frederic Weisbecker
callchains When the callchain tree comes to insert an empty backtrace, it raises a spurious warning about the fact we are inserting an empty. This is spurious because the radix tree assumes it did something wrong to reach this state. But it didn't, we just met an empty callchain that has to be ignored. This happens occasionally with certain types of call-chain recordings. If it happens it's a big nuisance as perf report output starts with thousands of warning lines. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <1249690585-9145-2-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-09perf tools: Fix call-chain cumul hit based sub-total (fractal mode)Frederic Weisbecker
The callchain fractal mode builds each new total hits in a new branch of profiling by using the parent's hits of the current branch plus the hits of the children. This is wrong, the total hits of a branch should be made of the sum of every children hits, we must ignore the parent hits in this scope. This patch also fixes another mistake with the hit counting. Now the rates are correct. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-05perf report: Add "Fractal" mode output - support callchains with relative ↵Frederic Weisbecker
overhead rate 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 <fweisbec@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Anton Blanchard <anton@samba.org> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <1246772361-9960-5-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-05perf_counter tools: callchains: Manage the cumul hits on the flyFrederic Weisbecker
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: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Anton Blanchard <anton@samba.org> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <1246772361-9960-4-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-02perf_counter tools: Set the minimum percent for callchains to be displayedFrederic Weisbecker
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 <fweisbec@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Anton Blanchard <anton@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <1246558475-10624-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-02perf report: Add support for callchain graph outputFrederic Weisbecker
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 <fweisbec@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Anton Blanchard <anton@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <1246550301-8954-3-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-02perf_counter tools: Create new chain_for_each_child() iteratorFrederic Weisbecker
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: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Anton Blanchard <anton@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <1246550301-8954-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-01perf_counter tools: Add more warnings and fix/annotate themIngo Molnar
Enable -Wextra. This found a few real bugs plus a number of signed/unsigned type mismatches/uncleanlinesses. It also required a few annotations All things considered it was still worth it so lets try with this enabled for now. 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: Ingo Molnar <mingo@elte.hu>
2009-07-01perf_counter tools: Various fixes for callchainsFrederic Weisbecker
The symbol resolving has of course revealed some bugs in the callchain tree handling. This patch fixes some of them, including: - inherit the children from the parents while splitting a node - fix list range moving - fix indexes setting in callchains - create a child on the current node if the path doesn't match in the existent children (was only done on the root) - compare using symbols when possible so that we can match a function using any ip inside by referring to its start address. The practical effects are: - remove double callchains - fix upside down or any random order of callchains - fix wrong paths - fix bad hits and percentage accounts Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Anton Blanchard <anton@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <1246419315-9968-4-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-01perf_counter tools: Resolve symbols in callchainsFrederic Weisbecker
This patch resolves the names, when possible, of each ip present in the callchains while using the -c option with perf report. Example: 5.40% [k] __d_lookup 5.37% perf_callchain perf_counter_overflow intel_pmu_handle_irq perf_counter_nmi_handler notifier_call_chain atomic_notifier_call_chain notify_die do_nmi nmi do_lookup __link_path_walk path_walk do_path_lookup user_path_at sys_faccessat sys_access system_call_fastpath 0x7fb609846f77 0.01% perf_callchain perf_counter_overflow intel_pmu_handle_irq perf_counter_nmi_handler notifier_call_chain atomic_notifier_call_chain notify_die do_nmi nmi do_lookup __link_path_walk path_walk do_path_lookup user_path_at sys_faccessat Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Anton Blanchard <anton@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <1246419315-9968-3-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-01perf_counter tools: Fix storage size allocation of callchain listFrederic Weisbecker
Fix a confusion while giving the size of a callchain list during its allocation. We are using the wrong structure size. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Anton Blanchard <anton@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <1246419315-9968-2-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-26perf_counter tools: Prepare a small callchain frameworkFrederic Weisbecker
We plan to display the callchains depending on some user-configurable parameters. To gather the callchains stats from the recorded stream in a fast way, this patch introduces an ad hoc radix tree adapted for callchains and also a rbtree to sort these callchains once we have gathered every events from the stream. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1246026481-8314-2-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>