From nobody Sat Oct 11 11:47:14 2025 Received: from mail-pg1-f202.google.com (mail-pg1-f202.google.com [209.85.215.202]) (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 9EB8B22C355 for ; Wed, 11 Jun 2025 03:46:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749613593; cv=none; b=B3CNwqDeNz/y46wA8hSrv3m9fExrgdBqFW+dQDTmYTShB/wg8JzERWjs9z4+KqadVaOR1AJf2oR77LkVCcAJFbzbq7kmS3BbjYQPi1ayLl9p8fFDuFzGLDB+r93B9gb8BGwnuP/B1i2Y83VfMqOodY8a77Z5Pgw9XFulVVH2vd4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749613593; c=relaxed/simple; bh=AeW/Ac3QkfBwRXLWBdChkTIwfvl/5RVURnMQ1MrqODQ=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Content-Type; b=L5WHwmJimN3qE1zmrQsORNbgHMsOsAcaowTz1s09ax0ZeP9Bz+3tELbzYgP7crUr4biw8TzhuT6RuoiB1nHniY/XJHrowXo0kvK6pBmKdXuZywNh25zYhHQD4qaAsd/1GrqEKkmvoTNeNVKG6PVLAbjF6NMafwyxfCgwfzdn130= 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=zUBfLsXw; arc=none smtp.client-ip=209.85.215.202 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="zUBfLsXw" Received: by mail-pg1-f202.google.com with SMTP id 41be03b00d2f7-b2eb60594e8so3602851a12.1 for ; Tue, 10 Jun 2025 20:46:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1749613591; x=1750218391; 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=JKIwovJpQlk9CWotuuE1W1NkF/IomItix7FAi+RBbSI=; b=zUBfLsXwqkT3mxHbO7Kw7wdkQGgjupJ1brnXvUByTwRQ0U88Il39dXV4r5aX5ZH21f gjwNIJhjd3q8pW3nkX6a2pXB7dRNbDz6SIKy16ywLPxDmKxnZKYIj5RvBGXIWTF5AfBk aVrRAeA8aMJdXGKulVvn69eC+CtANTguo/mGDiY6TP2HBQAaYdnal8GlMpgtp+0K6sUY 1Q+CyPpwORBoNWo6+BC3FCGupYQelAHZ220eksHxL3DfR0jVJg1ulKF8OA0O7EN88rF5 cDRtojNCq6eYGHyYt2S/p70KBooqZITYGgdaUSTbx6JDzyI1418tvPeOc76fPmaDlu1M 6VYA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1749613591; x=1750218391; 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=JKIwovJpQlk9CWotuuE1W1NkF/IomItix7FAi+RBbSI=; b=R6oTzzCIz214U5XKEuldBtgKWx52TLZom7tTDotBRQmai7AG/1uoYEtsN/bqbYhmDa 5StsARFVu6QIB8L7btnNjnbBHs9/6qw75OcpPt8ScFCqQGpIfBqt9mEgWyajscShjYe1 jfxo8dM7Pmzo7tdLgex+iEaxdjH0okjSiGyWblC2ElmTx9jYHXcMJTVe4N4UOpmw5Wnt Wqpk9m09HMU8TQlRgYFym8Zr9oo6r25r4k20uOq/878ndSUHkc8NdEO5iu7/9vJPDmiU OG6/8kgy8NCVgBTLjC2DQy9PHGvrbZ7tsWFTeyHhT9nuD+ySgfdjoMF/k9BRuMUEnvmz 9G2Q== X-Forwarded-Encrypted: i=1; AJvYcCV/Pv0VlshHcwqzW5hvIXAjsbHawhAYUP1ZJvzfGXaFPb4cFrsKIR+oeD6unLMAdEIQFdo7AepHrlwHItk=@vger.kernel.org X-Gm-Message-State: AOJu0YykqZv1jOVPtlcCCwxQzcFP4VpiALJ9rg5Kl1RVbdEDbG0O1LRL yMAC2mRvfI4Y3QRe/WV2QAvTfomjIzE6Yk/YBKjJjFi9mRxS9woE16RsL7OknnQ40JFgaEQ6VFc RBRSC4c6Hug== X-Google-Smtp-Source: AGHT+IGK+vMYpdAwrp3b6Chw1tzqM16m3QZB+T7XOxBulDEWavXIAXWTFa3Hp0uZuBokPGk2SQhjhRKbXTl8 X-Received: from pgnd30.prod.google.com ([2002:a63:735e:0:b0:b29:82be:c692]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a21:6da0:b0:1f5:7007:9eb8 with SMTP id adf61e73a8af0-21f86651052mr2489185637.16.1749613591054; Tue, 10 Jun 2025 20:46:31 -0700 (PDT) Date: Tue, 10 Jun 2025 20:45:24 -0700 In-Reply-To: <20250611034529.508842-1-irogers@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250611034529.508842-1-irogers@google.com> X-Mailer: git-send-email 2.50.0.rc0.642.g800a2b2222-goog Message-ID: <20250611034529.508842-11-irogers@google.com> Subject: [PATCH v1 10/15] 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 , John Garry , "Masami Hiramatsu (Google)" , Howard Chu , Weilin Wang , Thomas Richter , Andi Kleen , Tiezhu Yang , Gautam Menghani , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org Content-Transfer-Encoding: quoted-printable 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 609828513f6c..4164c2278051 100644 --- a/tools/perf/util/pmu.c +++ b/tools/perf/util/pmu.c @@ -1181,6 +1181,32 @@ int perf_pmu__init(struct perf_pmu *pmu, __u32 type,= const char *name) return 0; } =20 +static __u32 wellknown_pmu_type(const char *pmu_name) +{ + struct { + const char *pmu_name; + __u32 type; + } wellknown_pmus[] =3D { + { + "software", + PERF_TYPE_SOFTWARE + }, + { + "tracepoint", + PERF_TYPE_TRACEPOINT + }, + { + "breakpoint", + PERF_TYPE_BREAKPOINT + }, + }; + for (size_t i =3D 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) { @@ -1200,8 +1226,12 @@ 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) !=3D 1) { - perf_pmu__delete(pmu); - return NULL; + /* Double check the PMU's name isn't wellknown. */ + pmu->type =3D wellknown_pmu_type(name); + if (pmu->type =3D=3D PERF_TYPE_MAX) { + perf_pmu__delete(pmu); + return NULL; + } } =20 /* --=20 2.50.0.rc0.642.g800a2b2222-goog