From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F2F0E166F16; Fri, 2 Aug 2024 18:21:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722622873; cv=none; b=NbFCt0ggpKgpUT14cMlSyTnvsgwauerFMQ5FkOo1MFSJ1fRHzgS70Fjcw+IU8bBMNEu2kkXMTfzUZye4AVi5PaTGNKM1hyOiQov/M555IGF9iAJtFY48FrvFC8FZGBRjx7zgHDYRBv0DBc2/tsZ4AbVfi40v7U+mlA2vAH+OHu4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722622873; c=relaxed/simple; bh=JPfxNE1HkT7S+SO31tOM4YJy8RSd9UqK2EwtYsA4LIo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=NR+8pI3+ctqm826/wYL9Z3+fqmD0hYKlq2PezxR7KvoA4btyj7bBMoSlq1wov7E+Y6R93odKRWdE0ykERaE8iOfj98Xe78Cm2Q0dBKS4pGurAV8G9hJVi43Dc5SQ2e6a3U/QIwaLRHoipFN4lGk4qyyrp4Pg0ZEqCeGEcF3HpTE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=fHArcFMz; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="fHArcFMz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 26A9BC4AF09; Fri, 2 Aug 2024 18:21:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1722622872; bh=JPfxNE1HkT7S+SO31tOM4YJy8RSd9UqK2EwtYsA4LIo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=fHArcFMzXWFo2LhphJghxbBkGwlItvYyluDndKYoyjvnIVwjCZGTwhKoJ1Ky+sa9T xZ7WQWfa8JgMk5G6ijX+AFaA5fQxwUK73lS7rIy13hUtbAGOI0469t4cRqvXkY+HMs oO066GJhzvWHgnQuXQ3AzIPG0Y3P65FVHwjdSYLGrGibmicJSo/RC/fR8OD4nCRJKL Tgig0ufNKyoMEOTxK/gbZTXN0Lr6+lvHL8eaVzrubV0R2fPE8JXOFZxjdFA7zQbU7c kr6p5ocfDdxE5/lMu2ymOqukHtwUImPTEQzULF5Z8RXR5aLYuCPD3dYTLi/rskEuUB DiyfLg5JjciiA== Date: Fri, 2 Aug 2024 11:21:09 -0700 From: Namhyung Kim To: Ben Gainey Cc: peterz@infradead.org, mingo@redhat.com, acme@kernel.org, james.clark@arm.com, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, irogers@google.com, adrian.hunter@intel.com, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v10 1/2] tools/perf: Correctly calculate sample period for inherited SAMPLE_READ values Message-ID: References: <20240801123030.3075928-1-ben.gainey@arm.com> <20240801123030.3075928-2-ben.gainey@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20240801123030.3075928-2-ben.gainey@arm.com> On Thu, Aug 01, 2024 at 01:30:29PM +0100, Ben Gainey wrote: > Sample period calculation in deliver_sample_value is updated to > calculate the per-thread period delta for events that are inherit + > PERF_SAMPLE_READ. When the sampling event has this configuration, the > read_format.id is used with the tid from the sample to lookup the > storage of the previously accumulated counter total before calculating > the delta. All existing valid configurations where read_format.value > represents some global value continue to use just the read_format.id to > locate the storage of the previously accumulated total. > > perf_sample_id is modified to support tracking per-thread > values, along with the existing global per-id values. In the > per-thread case, values are stored in a hash by tid within the > perf_sample_id, and are dynamically allocated as the number is not known > ahead of time. > > Signed-off-by: Ben Gainey > --- > tools/lib/perf/evsel.c | 48 +++++++++++++++++++ > tools/lib/perf/include/internal/evsel.h | 63 ++++++++++++++++++++++++- > tools/perf/util/session.c | 25 ++++++---- > 3 files changed, 126 insertions(+), 10 deletions(-) > > diff --git a/tools/lib/perf/evsel.c b/tools/lib/perf/evsel.c > index c07160953224..abdae2f9498b 100644 > --- a/tools/lib/perf/evsel.c > +++ b/tools/lib/perf/evsel.c > @@ -5,6 +5,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -23,6 +24,7 @@ void perf_evsel__init(struct perf_evsel *evsel, struct perf_event_attr *attr, > int idx) > { > INIT_LIST_HEAD(&evsel->node); > + INIT_LIST_HEAD(&evsel->per_stream_periods); > evsel->attr = *attr; > evsel->idx = idx; > evsel->leader = evsel; > @@ -531,10 +533,56 @@ int perf_evsel__alloc_id(struct perf_evsel *evsel, int ncpus, int nthreads) > > void perf_evsel__free_id(struct perf_evsel *evsel) > { > + struct perf_sample_id_period *pos, *n; > + > xyarray__delete(evsel->sample_id); > evsel->sample_id = NULL; > zfree(&evsel->id); > evsel->ids = 0; > + > + perf_evsel_for_each_per_thread_period_safe(evsel, n, pos) { > + list_del_init(&pos->node); > + free(pos); > + } > +} > + > +bool perf_evsel__attr_has_per_thread_sample_period(struct perf_evsel *evsel) > +{ > + return (evsel->attr.sample_type & PERF_SAMPLE_READ) > + && (evsel->attr.sample_type & PERF_SAMPLE_TID) > + && evsel->attr.inherit; Nitpick: I believe the coding style wants to put the operators at the end of the line like return (evsel->attr.sample_type & PERF_SAMPLE_READ) && (evsel->attr.sample_type & PERF_SAMPLE_TID) && evsel->attr.inherit; Thanks, Namhyung > +} > + > +u64 *perf_sample_id__get_period_storage(struct perf_sample_id *sid, u32 tid, bool per_thread) > +{ > + struct hlist_head *head; > + struct perf_sample_id_period *res; > + int hash; > + > + if (!per_thread) > + return &sid->period; > + > + hash = hash_32(tid, PERF_SAMPLE_ID__HLIST_BITS); > + head = &sid->periods[hash]; > + > + hlist_for_each_entry(res, head, hnode) > + if (res->tid == tid) > + return &res->period; > + > + if (sid->evsel == NULL) > + return NULL; > + > + res = zalloc(sizeof(struct perf_sample_id_period)); > + if (res == NULL) > + return NULL; > + > + INIT_LIST_HEAD(&res->node); > + res->tid = tid; > + > + list_add_tail(&res->node, &sid->evsel->per_stream_periods); > + hlist_add_head(&res->hnode, &sid->periods[hash]); > + > + return &res->period; > } > > void perf_counts_values__scale(struct perf_counts_values *count, > diff --git a/tools/lib/perf/include/internal/evsel.h b/tools/lib/perf/include/internal/evsel.h > index 5cd220a61962..ea78defa77d0 100644 > --- a/tools/lib/perf/include/internal/evsel.h > +++ b/tools/lib/perf/include/internal/evsel.h > @@ -11,6 +11,32 @@ > struct perf_thread_map; > struct xyarray; > > +/** > + * The per-thread accumulated period storage node. > + */ > +struct perf_sample_id_period { > + struct list_head node; > + struct hlist_node hnode; > + /* Holds total ID period value for PERF_SAMPLE_READ processing. */ > + u64 period; > + /* The TID that the values belongs to */ > + u32 tid; > +}; > + > +/** > + * perf_evsel_for_each_per_thread_period_safe - safely iterate thru all the > + * per_stream_periods > + * @evlist:perf_evsel instance to iterate > + * @item: struct perf_sample_id_period iterator > + * @tmp: struct perf_sample_id_period temp iterator > + */ > +#define perf_evsel_for_each_per_thread_period_safe(evsel, tmp, item) \ > + list_for_each_entry_safe(item, tmp, &(evsel)->per_stream_periods, node) > + > + > +#define PERF_SAMPLE_ID__HLIST_BITS 4 > +#define PERF_SAMPLE_ID__HLIST_SIZE (1 << PERF_SAMPLE_ID__HLIST_BITS) > + > /* > * Per fd, to map back from PERF_SAMPLE_ID to evsel, only used when there are > * more than one entry in the evlist. > @@ -34,8 +60,32 @@ struct perf_sample_id { > pid_t machine_pid; > struct perf_cpu vcpu; > > - /* Holds total ID period value for PERF_SAMPLE_READ processing. */ > - u64 period; > + /* > + * Per-thread, and global event counts are mutually exclusive: > + * Whilst it is possible to combine events into a group with differing > + * values of PERF_SAMPLE_READ, it is not valid to have inconsistent > + * values for `inherit`. Therefore it is not possible to have a > + * situation where a per-thread event is sampled as a global event; > + * all !inherit groups are global, and all groups where the sampling > + * event is inherit + PERF_SAMPLE_READ will be per-thread. Any event > + * that is part of such a group that is inherit but not PERF_SAMPLE_READ > + * will be read as per-thread. If such an event can also trigger a > + * sample (such as with sample_period > 0) then it will not cause > + * `read_format` to be included in its PERF_RECORD_SAMPLE, and > + * therefore will not expose the per-thread group members as global. > + */ > + union { > + /* > + * Holds total ID period value for PERF_SAMPLE_READ processing > + * (when period is not per-thread). > + */ > + u64 period; > + /* > + * Holds total ID period value for PERF_SAMPLE_READ processing > + * (when period is per-thread). > + */ > + struct hlist_head periods[PERF_SAMPLE_ID__HLIST_SIZE]; > + }; > }; > > struct perf_evsel { > @@ -58,6 +108,10 @@ struct perf_evsel { > u32 ids; > struct perf_evsel *leader; > > + /* For events where the read_format value is per-thread rather than > + * global, stores the per-thread cumulative period */ > + struct list_head per_stream_periods; > + > /* parse modifier helper */ > int nr_members; > /* > @@ -88,4 +142,9 @@ int perf_evsel__apply_filter(struct perf_evsel *evsel, const char *filter); > int perf_evsel__alloc_id(struct perf_evsel *evsel, int ncpus, int nthreads); > void perf_evsel__free_id(struct perf_evsel *evsel); > > +bool perf_evsel__attr_has_per_thread_sample_period(struct perf_evsel *evsel); > + > +u64 *perf_sample_id__get_period_storage(struct perf_sample_id *sid, u32 tid, > + bool per_thread); > + > #endif /* __LIBPERF_INTERNAL_EVSEL_H */ > diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c > index 5596bed1b8c8..fac0557ff6ea 100644 > --- a/tools/perf/util/session.c > +++ b/tools/perf/util/session.c > @@ -1474,18 +1474,24 @@ static int deliver_sample_value(struct evlist *evlist, > union perf_event *event, > struct perf_sample *sample, > struct sample_read_value *v, > - struct machine *machine) > + struct machine *machine, > + bool per_thread) > { > struct perf_sample_id *sid = evlist__id2sid(evlist, v->id); > struct evsel *evsel; > + u64 *storage = NULL; > > if (sid) { > + storage = perf_sample_id__get_period_storage(sid, sample->tid, per_thread); > + } > + > + if (storage) { > sample->id = v->id; > - sample->period = v->value - sid->period; > - sid->period = v->value; > + sample->period = v->value - *storage; > + *storage = v->value; > } > > - if (!sid || sid->evsel == NULL) { > + if (!storage || sid->evsel == NULL) { > ++evlist->stats.nr_unknown_id; > return 0; > } > @@ -1506,14 +1512,15 @@ static int deliver_sample_group(struct evlist *evlist, > union perf_event *event, > struct perf_sample *sample, > struct machine *machine, > - u64 read_format) > + u64 read_format, > + bool per_thread) > { > int ret = -EINVAL; > struct sample_read_value *v = sample->read.group.values; > > sample_read_group__for_each(v, sample->read.group.nr, read_format) { > ret = deliver_sample_value(evlist, tool, event, sample, v, > - machine); > + machine, per_thread); > if (ret) > break; > } > @@ -1528,6 +1535,7 @@ static int evlist__deliver_sample(struct evlist *evlist, struct perf_tool *tool, > /* We know evsel != NULL. */ > u64 sample_type = evsel->core.attr.sample_type; > u64 read_format = evsel->core.attr.read_format; > + bool per_thread = perf_evsel__attr_has_per_thread_sample_period(&evsel->core); > > /* Standard sample delivery. */ > if (!(sample_type & PERF_SAMPLE_READ)) > @@ -1536,10 +1544,11 @@ static int evlist__deliver_sample(struct evlist *evlist, struct perf_tool *tool, > /* For PERF_SAMPLE_READ we have either single or group mode. */ > if (read_format & PERF_FORMAT_GROUP) > return deliver_sample_group(evlist, tool, event, sample, > - machine, read_format); > + machine, read_format, per_thread); > else > return deliver_sample_value(evlist, tool, event, sample, > - &sample->read.one, machine); > + &sample->read.one, machine, > + per_thread); > } > > static int machines__deliver_event(struct machines *machines, > -- > 2.45.2 >