Messages in this thread | | | Date | Tue, 25 Aug 2015 10:22:28 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH v2 0/6] perf: Introduce extended syscall error reporting |
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* Alexander Shishkin <alexander.shishkin@linux.intel.com> wrote:
> Hi Peter and Ingo and everybody, > > Here's an update of my extended error reporting patchset, addressing > review comments and adding a few more error messages to PT and BTS > drivers. > > Changes since v1: > * addressed Peter's comments, > * added perf_err() annotation to intel_pt and intel_bts drivers; > especially the former is rich in EINVALs in event validation path, > so it should be immediately useful; > * changed the error code to EINVAL for the case when perf_err() is > supplied a non-constart error code; > * dropped RFC, added sign-offs. > > This time around, I employed a linker trick to convert the structures > containing extended error information into integers, which are then > made to look just like normal error codes so that IS_ERR_VALUE() and > friends would still work correctly on them. So no extra pointers in > the struct perf_event or anywhere else; the extended error codes are > passed around like normal error codes. They only need to be converted > in syscalls' topmost return statements. This is done in 1/6.
Nice trick!
> Then, 2/6 illustrates how error sites can be extended to include more > information such as file names and line numbers [1]. Side note, it can > be dropped without impact on other patches. > > The other patches add perf_err() annotation to a few semi-randomly > picked places in perf core (3/6), x86 bits (4/6), intel_pt (5/6) and > intel_bts (6/6). > > [1] http://marc.info/?l=linux-kernel&m=141471816115946 > > Alexander Shishkin (6): > perf: Introduce extended syscall error reporting > perf: Add file name and line number to perf extended error reports > perf: Annotate some of the error codes with perf_err() > perf/x86: Annotate some of the error codes with perf_err() > perf/x86/intel/pt: Use extended error reporting in event > initialization > perf/x86/intel/bts: Use extended error reporting in event > initialization > > arch/x86/kernel/cpu/perf_event.c | 8 +- > arch/x86/kernel/cpu/perf_event_intel_bts.c | 4 +- > arch/x86/kernel/cpu/perf_event_intel_lbr.c | 2 +- > arch/x86/kernel/cpu/perf_event_intel_pt.c | 29 +++++--- > include/linux/perf_event.h | 82 +++++++++++++++++++++ > include/uapi/linux/perf_event.h | 8 +- > kernel/events/core.c | 113 +++++++++++++++++++++++++---- > 7 files changed, 215 insertions(+), 31 deletions(-)
Ok, this looks pretty good to me.
Mind adding support on the perf tooling side as well, so that it can be tested and applied in a single set of patches?
Thanks,
Ingo
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