From f9bd6f63cf782d2c29ee049bc43a49d0a8ca65b4 Mon Sep 17 00:00:00 2001 From: Andrew Murray Date: Thu, 10 Jan 2019 13:53:25 +0000 Subject: [PATCH 0222/2944] ICX: perf/core: Add PERF_PMU_CAP_NO_EXCLUDE for exclusion incapable PMUs commit cc6795aeffea0a80d0baf9ad31ba926a6c42cef5 upstream. Many PMU drivers do not have the capability to exclude counting events that occur in specific contexts such as idle, kernel, guest, etc. These drivers indicate this by returning an error in their event_init upon testing the events attribute flags. This approach is error prone and often inconsistent. Let's instead allow PMU drivers to advertise their inability to exclude based on context via a new capability: PERF_PMU_CAP_NO_EXCLUDE. This allows the perf core to reject requests for exclusion events where there is no support in the PMU. Signed-off-by: Andrew Murray Signed-off-by: Peter Zijlstra (Intel) Cc: Arnaldo Carvalho de Melo Cc: Benjamin Herrenschmidt Cc: Borislav Petkov Cc: Ivan Kokshaysky Cc: Linus Torvalds Cc: Mark Rutland Cc: Matt Turner Cc: Michael Ellerman Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Richard Henderson Cc: Russell King Cc: Sascha Hauer Cc: Shawn Guo Cc: Thomas Gleixner Cc: Will Deacon Cc: linux-arm-kernel@lists.infradead.org Cc: linuxppc-dev@lists.ozlabs.org Cc: robin.murphy@arm.com Cc: suzuki.poulose@arm.com Link: https://lkml.kernel.org/r/1547128414-50693-4-git-send-email-andrew.murray@arm.com Signed-off-by: Ingo Molnar Signed-off-by: Shen, Xiaochen Signed-off-by: Jeffle Xu Acked-by: Joseph Qi Acked-by: Caspar Zhang --- include/linux/perf_event.h | 1 + kernel/events/core.c | 9 +++++++++ 2 files changed, 10 insertions(+) diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 2558767..23d9722 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -243,6 +243,7 @@ struct hw_perf_event { #define PERF_PMU_CAP_EXCLUSIVE 0x10 #define PERF_PMU_CAP_ITRACE 0x20 #define PERF_PMU_CAP_HETEROGENEOUS_CPUS 0x40 +#define PERF_PMU_CAP_NO_EXCLUDE 0x80 /** * struct pmu - generic performance monitoring unit diff --git a/kernel/events/core.c b/kernel/events/core.c index 460d5fd..c22eae0 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -9817,6 +9817,15 @@ static int perf_try_init_event(struct pmu *pmu, struct perf_event *event) if (ctx) perf_event_ctx_unlock(event->group_leader, ctx); + if (!ret) { + if (pmu->capabilities & PERF_PMU_CAP_NO_EXCLUDE && + event_has_any_exclude_flag(event)) { + if (event->destroy) + event->destroy(event); + ret = -EINVAL; + } + } + if (ret) module_put(pmu->module); -- 1.8.3.1