Messages in this thread | | | Subject | Re: [PATCH v2 6/7] perf cs-etm: Detect pid in VMID for kernel running at EL2 | From | Suzuki K Poulose <> | Date | Tue, 2 Feb 2021 23:29:47 +0000 |
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On 2/2/21 4:38 PM, Leo Yan wrote: > From: Suzuki K Poulose <suzuki.poulose@arm.com> > > The PID of the task could be traced as VMID when the kernel is running > at EL2. Teach the decoder to look for VMID when the CONTEXTIDR (Arm32) > or CONTEXTIDR_EL1 (Arm64) is invalid but we have a valid VMID. > > Cc: Mike Leach <mike.leach@linaro.org> > Cc: Mathieu Poirier <mathieu.poirier@linaro.org> > Cc: Al Grant <al.grant@arm.com> > Co-developed-by: Leo Yan <leo.yan@linaro.org> > Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> > Signed-off-by: Leo Yan <leo.yan@linaro.org> > --- > .../perf/util/cs-etm-decoder/cs-etm-decoder.c | 32 ++++++++++++++++--- > 1 file changed, 28 insertions(+), 4 deletions(-) > > diff --git a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c > index 3f4bc4050477..fb2a163ff74e 100644 > --- a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c > +++ b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c > @@ -6,6 +6,7 @@ > * Author: Mathieu Poirier <mathieu.poirier@linaro.org> > */ > > +#include <linux/coresight-pmu.h> > #include <linux/err.h> > #include <linux/list.h> > #include <linux/zalloc.h> > @@ -491,13 +492,36 @@ cs_etm_decoder__set_tid(struct cs_etm_queue *etmq, > const ocsd_generic_trace_elem *elem, > const uint8_t trace_chan_id) > { > - pid_t tid; > + pid_t tid = -1; > + u64 pid_fmt; > + int ret; > > - /* Ignore PE_CONTEXT packets that don't have a valid contextID */ > - if (!elem->context.ctxt_id_valid) > + ret = cs_etm__get_pid_fmt(trace_chan_id, &pid_fmt); > + if (ret)
Is this something we can cache in this function ? e.g, static u64 pid_fmt;
if (!pid_pfmt) ret = cs_etm__get_pid_fmt(trace_chan_id, &pid_fmt);
As all the ETMs will be running at the same exception level.
> + return OCSD_RESP_FATAL_SYS_ERR; > + > + /* > + * Process the PE_CONTEXT packets if we have a valid contextID or VMID. > + * If the kernel is running at EL2, the PID is traced in CONTEXTIDR_EL2 > + * as VMID, Bit ETM_OPT_CTXTID2 is set in this case. > + */ > + switch (pid_fmt) { > + case BIT(ETM_OPT_CTXTID): > + if (elem->context.ctxt_id_valid) > + tid = elem->context.context_id; > + break; > + case BIT(ETM_OPT_CTXTID2) | BIT(ETM_OPT_CTXTID):
I would rather fix the cs_etm__get_pid_fmt() to return either of these as commented. i.e, ETM_OPT_CTXTID or ETM_OPT_CTXTID2. Thus we don't need the this case.
With the above two addressed:
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
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