Messages in this thread | | | Subject | Re: [PATCH] perf script python: Fix buffer size to report iregs in perf script | From | Nageswara Sastry <> | Date | Mon, 28 Jun 2021 12:45:36 +0530 |
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Tested by creating perf-script.py using perf script and priting the iregs. Seen more values with this patch.
Tested-by: Nageswara R Sastry <rnsastry@linux.ibm.com>
On 28/06/21 11:53 am, Kajol Jain wrote: > Commit 48a1f565261d ("perf script python: Add more PMU fields > to event handler dict") added functionality to report fields like > weight, iregs, uregs etc via perf report. > That commit predefined buffer size to 512 bytes to print those fields. > > But incase of powerpc, since we added extended regs support > in commits: > > Commit 068aeea3773a ("perf powerpc: Support exposing Performance Monitor > Counter SPRs as part of extended regs") > Commit d735599a069f ("powerpc/perf: Add extended regs support for > power10 platform") > > Now iregs can carry more bytes of data and this predefined buffer size > can result to data loss in perf script output. > > Patch resolve this issue by making buffer size dynamic based on number > of registers needed to print. It also changed return type for function > "regs_map" from int to void, as the return value is not being used by > the caller function "set_regs_in_dict". > > Fixes: 068aeea3773a ("perf powerpc: Support exposing Performance Monitor > Counter SPRs as part of extended regs") > Signed-off-by: Kajol Jain <kjain@linux.ibm.com> > --- > .../util/scripting-engines/trace-event-python.c | 17 ++++++++++++----- > 1 file changed, 12 insertions(+), 5 deletions(-) > > diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c > index 4e4aa4c97ac5..c8c9706b4643 100644 > --- a/tools/perf/util/scripting-engines/trace-event-python.c > +++ b/tools/perf/util/scripting-engines/trace-event-python.c > @@ -687,7 +687,7 @@ static void set_sample_datasrc_in_dict(PyObject *dict, > _PyUnicode_FromString(decode)); > } > > -static int regs_map(struct regs_dump *regs, uint64_t mask, char *bf, int size) > +static void regs_map(struct regs_dump *regs, uint64_t mask, char *bf, int size) > { > unsigned int i = 0, r; > int printed = 0; > @@ -695,7 +695,7 @@ static int regs_map(struct regs_dump *regs, uint64_t mask, char *bf, int size) > bf[0] = 0; > > if (!regs || !regs->regs) > - return 0; > + return; > > for_each_set_bit(r, (unsigned long *) &mask, sizeof(mask) * 8) { > u64 val = regs->regs[i++]; > @@ -704,8 +704,6 @@ static int regs_map(struct regs_dump *regs, uint64_t mask, char *bf, int size) > "%5s:0x%" PRIx64 " ", > perf_reg_name(r), val); > } > - > - return printed; > } > > static void set_regs_in_dict(PyObject *dict, > @@ -713,7 +711,16 @@ static void set_regs_in_dict(PyObject *dict, > struct evsel *evsel) > { > struct perf_event_attr *attr = &evsel->core.attr; > - char bf[512]; > + > + /* > + * Here value 28 is a constant size which can be used to print > + * one register value and its corresponds to: > + * 16 chars is to specify 64 bit register in hexadecimal. > + * 2 chars is for appending "0x" to the hexadecimal value and > + * 10 chars is for register name. > + */ > + int size = __sw_hweight64(attr->sample_regs_intr) * 28; > + char bf[size]; > > regs_map(&sample->intr_regs, attr->sample_regs_intr, bf, sizeof(bf)); > >
-- Thanks and Regards R.Nageswara Sastry
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