Messages in this thread Patch in this message | | | Date | Mon, 10 Jul 2023 08:37:52 -0000 | From | "tip-bot2 for Ravi Bangoria" <> | Subject | [tip: perf/core] perf/amd: Prevent grouping of IBS events |
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The following commit has been merged into the perf/core branch of tip:
Commit-ID: 7c2128235eff99b448af8f4b5b2933495bf1a440 Gitweb: https://git.kernel.org/tip/7c2128235eff99b448af8f4b5b2933495bf1a440 Author: Ravi Bangoria <ravi.bangoria@amd.com> AuthorDate: Tue, 20 Jun 2023 14:46:03 +05:30 Committer: Peter Zijlstra <peterz@infradead.org> CommitterDate: Mon, 10 Jul 2023 09:52:34 +02:00
perf/amd: Prevent grouping of IBS events
IBS PMUs can have only one event active at any point in time. Restrict grouping of multiple IBS events.
Reported-by: Sandipan Das <sandipan.das@amd.com> Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20230620091603.269-1-ravi.bangoria@amd.com --- arch/x86/events/amd/ibs.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+)
diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c index 3710148..74e6642 100644 --- a/arch/x86/events/amd/ibs.c +++ b/arch/x86/events/amd/ibs.c @@ -247,11 +247,33 @@ int forward_event_to_ibs(struct perf_event *event) return -ENOENT; } +/* + * Grouping of IBS events is not possible since IBS can have only + * one event active at any point in time. + */ +static int validate_group(struct perf_event *event) +{ + struct perf_event *sibling; + + if (event->group_leader == event) + return 0; + + if (event->group_leader->pmu == event->pmu) + return -EINVAL; + + for_each_sibling_event(sibling, event->group_leader) { + if (sibling->pmu == event->pmu) + return -EINVAL; + } + return 0; +} + static int perf_ibs_init(struct perf_event *event) { struct hw_perf_event *hwc = &event->hw; struct perf_ibs *perf_ibs; u64 max_cnt, config; + int ret; perf_ibs = get_ibs_pmu(event->attr.type); if (!perf_ibs) @@ -265,6 +287,10 @@ static int perf_ibs_init(struct perf_event *event) if (config & ~perf_ibs->config_mask) return -EINVAL; + ret = validate_group(event); + if (ret) + return ret; + if (hwc->sample_period) { if (config & perf_ibs->cnt_mask) /* raw max_cnt may not be set */
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