Messages in this thread | | | Date | Wed, 28 Jan 2009 18:10:52 -0800 | From | Corey Ashford <> | Subject | Re: [announce] Performance Counters for Linux, v6 |
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Ingo Molnar wrote: > We are pleased to announce version 6 of our performance counters subsystem > implementation. The shortlog, diffstat and the combo patch can be found > below. The combo patch against latest -git (2.6.29-rc2) can be also found > at: > > http://people.redhat.com/mingo/perfcounters/perfcounters-v6-v2.6.29-rc2.patch > > It's also available in tip/master at: > > http://people.redhat.com/mingo/tip.git/README > > There are many changes in the v6 release: > > - PowerPC performance counters support from Paul Mackerras, for POWER6 > and for the PPC970 family. > > - ioctl API to disable/enable individual counters and groups without > closing their fd. This can be useful for libraries, ad-hoc > instrumentation and PAPI support. > > - 'pinned' and 'exclusive' counter attributes - for those > applications that want to influence counter scheduling explicitly. > > - The 'perfstat' utility (ex 'timec') has been updated: > > http://people.redhat.com/mingo/perfcounters/perfstat.c > > - 'kerneltop' (easy-to-use text mode NMI profiler) has been updated: > > http://people.redhat.com/mingo/perfcounters/kerneltop.c > > - Merged to latest mainline > > - Various fixes and other updates > > Ingo
I'm not sure if this is the right place to propose such a thing, but I think it would be very valuable to have a standardized user-side library to accompany this addition to the kernel.
In particular, as a starting place for the discussion, I'd like to see functions in it that are very similar to a subset of what is currently in libpfm. Specifically, I'd like to see the following functions (with the names changed to pcl_* perhaps):
extern pfm_err_t pfm_find_event(const char *str, unsigned int *idx); extern pfm_err_t pfm_find_event_bycode(int code, unsigned int *idx); extern pfm_err_t pfm_find_event_bycode_next(int code, unsigned int start, unsigned int *next); extern pfm_err_t pfm_find_event_mask(unsigned int event_idx, const char *str, unsigned int *mask_idx); extern pfm_err_t pfm_find_full_event(const char *str, pfmlib_event_t *e);
extern pfm_err_t pfm_get_max_event_name_len(size_t *len);
extern pfm_err_t pfm_get_num_events(unsigned int *count); extern pfm_err_t pfm_get_num_event_masks(unsigned int event_idx, unsigned int *count); extern pfm_err_t pfm_get_event_name(unsigned int idx, char *name, size_t maxlen); extern pfm_err_t pfm_get_full_event_name(pfmlib_event_t *e, char *name, size_t maxlen); extern pfm_err_t pfm_get_event_code(unsigned int idx, int *code); extern pfm_err_t pfm_get_event_mask_code(unsigned int idx, unsigned int mask_idx, unsigned int *code); extern pfm_err_t pfm_get_event_description(unsigned int idx, char **str); extern pfm_err_t pfm_get_event_code_counter(unsigned int idx, unsigned int cnt, int *code); extern pfm_err_t pfm_get_event_mask_name(unsigned int event_idx, unsigned int mask_idx, char *name, size_t maxlen); extern pfm_err_t pfm_get_event_mask_description(unsigned int event_idx, unsigned int mask_idx, char **desc);
Now, since it's not clear right now how unit masks are going to be handled in your proposal, I'm not sure the that *_event_mask_* functions are applicable, but I think something that fills that function will be needed.
Architectures that have need for additional functionality should be free to add arch-specific functions.
Full descriptions of these functions can be found in the man pages of the libpfm documentation.
Any thoughts on this? Do you already have a user library structure in mind?
-- Regards,
- Corey
Corey Ashford Software Engineer IBM Linux Technology Center, Linux Toolchain Beaverton, OR 503-578-3507 cjashfor@us.ibm.com
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