From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f201.google.com (mail-pf1-f201.google.com [209.85.210.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 889F4248F52 for ; Wed, 9 Jul 2025 21:40:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752097243; cv=none; b=UoSsP32m92bTaDUW6FK8tmOnk80fKjqMYfbSDZyZZLl2kX44Ij7iFdgrdFblZeaSDZyO5DkQfDjHNjpdFYpbokt4W7RbjVjbVgqSusaNWMm5hI75oYkx7EJzYIb+1QlmcJy2kBK0octPQCyOv7VfWPVf2EgIXVPmPPiU7J2zwRE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752097243; c=relaxed/simple; bh=8+fzwKbYyh0HgEc4+oNZYk8ZhmbZCi8quzaYQRyDMRY=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Content-Type; b=KYpDEaL5qo5mNRPeJDxs3OUeLGHuLssDZgRXk8jyQeJ2r8zYnKEcex+/e4ArkDc2zV6S+Ld0XE6eHqi08chMDWdfUjYVFgt3YFJd+Rk8Xev0e7pPpAU6YJ99iy1LEy/TrhAzJete8o348DBO+yCkV9zdHulsNqYYRblsV/+TdgI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=rcZzNcEr; arc=none smtp.client-ip=209.85.210.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="rcZzNcEr" Received: by mail-pf1-f201.google.com with SMTP id d2e1a72fcca58-74913385dd8so413451b3a.0 for ; Wed, 09 Jul 2025 14:40:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1752097242; x=1752702042; darn=vger.kernel.org; h=to:from:subject:message-id:references:mime-version:in-reply-to:date :from:to:cc:subject:date:message-id:reply-to; bh=jB43BWOgr1OVnJk/vG7v3SNwpLjEdqHnInxVydle4NQ=; b=rcZzNcErVyUuTI4nsH102cf2L0gjFgkGyi/lkxRnA6lyu0g5JYxVWkdTUKCiNsDB+b oUR/bYiFVEeWlCFFSH1FATj7QVs2+ryEDDtknIDMQil7DOFSJhDG15e3X3s+IVzegF6s OF/SYE+tSvZhQm4/xxY+nxuvBJqsknwr4K9A5SrdOgm62HYfXl3EaoH/Bd36Idr4X2OA kUZB1wDkjMYWiNgmTln85kE+/IH/kTyn+2m/felf7HY6f/U2A5JT4WYWw5QdQIeC8vKY fRke8VBXAA7DEEucWqh3oTNwYFyI2jsOLhPsjIqj+c1jgvkKn4KUlypZ5uL73n1zN40r ntgw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1752097242; x=1752702042; h=to:from:subject:message-id:references:mime-version:in-reply-to:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=jB43BWOgr1OVnJk/vG7v3SNwpLjEdqHnInxVydle4NQ=; b=NXEphENg0TlxbMMeZuM8SRgur6NtaWSA/jNuK2aTo3EmcFvSaNQDpeH3dppjuRDc+u IEFP9FwT5xwwxc0Q6thvqfaMCWPHRkK4RH23XlcarYqvfu94KFdcvv5UlnRwaAhsBGLi janLS5wuR/Dc3xhO09uMA2oo1x4HLQ5CyONipDRsKjQD+i0cQ861XmsdluawDQnmLDVw wACbMarD4k8Qp2n7hPpfhwt5FB1gzWQeQZD6IlGMAzd4tL7j+ZZ7HVf/EvDZtQalsf5a iWFfZ20QUvOyK1XP8KSyG2QZFooey8yP6uN5Jj6oDkJUCAcSsfXNbfaxQI3JsTuB//iV 57Ng== X-Forwarded-Encrypted: i=1; AJvYcCWFZuNbMlv3WxQoOEs9BPeW4FNbyeBRcn0ixWGV3eswgkE96EqVVAwgNk8qxBqxBsSYBIywkuCaoE4r6/x6aPrn@vger.kernel.org X-Gm-Message-State: AOJu0Yw0+lO3vpZKEaX6/UHdMGUBN8nxiO/cd+BkEa53ZXtAE7zlqdkJ syOQFbZtSxK6EnMCUCrRVe9ywfwAv8GYJXgeVw/t7zWn8cNrjhdg5NTruVnVYbsz/3WJXHmmflz /IoXe81/1jQ== X-Google-Smtp-Source: AGHT+IEBtciJsh8xRDvIq+Sgsncs0zNYJD3rc0jF/WOqfdg3f+RccueHuYWIQOWwgAEZQpSuy2QQRcospvlu X-Received: from pgdk7.prod.google.com ([2002:a05:6a02:5467:b0:b31:c7e5:6664]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a20:7489:b0:220:9c00:6879 with SMTP id adf61e73a8af0-230045c6577mr308556637.17.1752097241840; Wed, 09 Jul 2025 14:40:41 -0700 (PDT) Date: Wed, 9 Jul 2025 14:40:21 -0700 In-Reply-To: <20250709214029.1769089-1-irogers@google.com> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250709214029.1769089-1-irogers@google.com> X-Mailer: git-send-email 2.50.0.727.gbf7dc18ff4-goog Message-ID: <20250709214029.1769089-5-irogers@google.com> Subject: [PATCH v1 04/12] perf pmu: Tolerate failure to read the type for wellknown PMUs From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , Kan Liang , James Clark , Xu Yang , Howard Chu , "Dr. David Alan Gilbert" , Levi Yun , Andi Kleen , Thomas Richter , Weilin Wang , Tiezhu Yang , Gautam Menghani , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" If sysfs isn't mounted then we may fail to read a PMU's type. In this situation resort to lookup of wellknown types. Only applies to software, tracepoint and breakpoint PMUs. Signed-off-by: Ian Rogers --- tools/perf/util/pmu.c | 34 ++++++++++++++++++++++++++++++++-- 1 file changed, 32 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c index f795883c233f..23666883049d 100644 --- a/tools/perf/util/pmu.c +++ b/tools/perf/util/pmu.c @@ -1182,6 +1182,32 @@ int perf_pmu__init(struct perf_pmu *pmu, __u32 type, const char *name) return 0; } +static __u32 wellknown_pmu_type(const char *pmu_name) +{ + struct { + const char *pmu_name; + __u32 type; + } wellknown_pmus[] = { + { + "software", + PERF_TYPE_SOFTWARE + }, + { + "tracepoint", + PERF_TYPE_TRACEPOINT + }, + { + "breakpoint", + PERF_TYPE_BREAKPOINT + }, + }; + for (size_t i = 0; i < ARRAY_SIZE(wellknown_pmus); i++) { + if (!strcmp(wellknown_pmus[i].pmu_name, pmu_name)) + return wellknown_pmus[i].type; + } + return PERF_TYPE_MAX; +} + struct perf_pmu *perf_pmu__lookup(struct list_head *pmus, int dirfd, const char *name, bool eager_load) { @@ -1201,8 +1227,12 @@ struct perf_pmu *perf_pmu__lookup(struct list_head *pmus, int dirfd, const char * that type value is successfully assigned (return 1). */ if (perf_pmu__scan_file_at(pmu, dirfd, "type", "%u", &pmu->type) != 1) { - perf_pmu__delete(pmu); - return NULL; + /* Double check the PMU's name isn't wellknown. */ + pmu->type = wellknown_pmu_type(name); + if (pmu->type == PERF_TYPE_MAX) { + perf_pmu__delete(pmu); + return NULL; + } } /* -- 2.50.0.727.gbf7dc18ff4-goog