From patchwork Fri Sep 8 12:32:44 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Janusz Krzysztofik X-Patchwork-Id: 13377429 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0B5D6EE7FE6 for ; Fri, 8 Sep 2023 12:34:53 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id F3EC010E8AB; Fri, 8 Sep 2023 12:34:46 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.93]) by gabe.freedesktop.org (Postfix) with ESMTPS id 8930210E8A7; Fri, 8 Sep 2023 12:34:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1694176481; x=1725712481; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=55V6t5Ju+XFqIVVIYdnF7/ugUTSZtBAc94mjKus7wbw=; b=WGYOKaa7TS/mrRV6F5xaiW0HbcjNTCj6B44kivVesIASkahNEgP0H212 dlzwUpN5aIGNMmb747UN8/Nr1l6YMHUuBZS2p1AK1gLr/K0t7o+OkgcYC XFzMx+yaSbguDDoIxZsI5l2forvRo18vN7ppaum3dwSqUbBlauUH5gAa3 elebWldFrvUe9n0CPWWkRBFjJcMes/cDsR9VXzuzBE05OjTkL6700zP0l FzzjMgCnMsXZVJ2YsvDJ5i1ZfcmC7mugr7r+DeY2qcuFmddXuS25zHLPP r9M0jn1x1YNkHunYXdjeu4q1h0nZdLxZAhryh2/HOxkam7U4REWGOHHi8 Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10827"; a="375015005" X-IronPort-AV: E=Sophos;i="6.02,237,1688454000"; d="scan'208";a="375015005" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Sep 2023 05:34:41 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10827"; a="857382018" X-IronPort-AV: E=Sophos;i="6.02,237,1688454000"; d="scan'208";a="857382018" Received: from jkrzyszt-mobl2.ger.corp.intel.com ([10.213.28.201]) by fmsmga002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Sep 2023 05:34:39 -0700 From: Janusz Krzysztofik To: igt-dev@lists.freedesktop.org Date: Fri, 8 Sep 2023 14:32:44 +0200 Message-ID: <20230908123233.137134-29-janusz.krzysztofik@linux.intel.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230908123233.137134-19-janusz.krzysztofik@linux.intel.com> References: <20230908123233.137134-19-janusz.krzysztofik@linux.intel.com> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH i-g-t v2 10/17] lib/ktap: Read /dev/kmsg in blocking mode X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: intel-gfx@lists.freedesktop.org, =?utf-8?q?Dominik_Karol_Pi=C4=85tkowski?= , Isabella Basso , Mauro Carvalho Chehab , intel-xe@lists.freedesktop.org Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" We obtain KTAP report from /dev/kmsg. That file is now opened from igt_ktest_begin(), a function originally designed for i915 selftests and now reused with kunit tests. The original intention of opening that file was to dump kernel messages to stderr on selftest error. For that purpose, the file is now opened in non-blocking mode so we don't end up waiting for more kernel messages than already available. Since our ktap parser code reuses the file descriptor, we now have to loop over EAGAIN responses, waiting for more KTAP data. Since we have no sleeps inside those loops, extremely high CPU usage can be observed. Simplify reading KTAP reports by first switching the file descriptor back to blocking mode. Signed-off-by: Janusz Krzysztofik Acked-by: Mauro Carvalho Chehab --- lib/igt_kmod.c | 7 ++++- lib/igt_ktap.c | 81 ++++++++++++++------------------------------------ 2 files changed, 28 insertions(+), 60 deletions(-) diff --git a/lib/igt_kmod.c b/lib/igt_kmod.c index fb0bd21ee5..020df286b8 100644 --- a/lib/igt_kmod.c +++ b/lib/igt_kmod.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include "igt_aux.h" @@ -758,12 +759,16 @@ static void __igt_kunit(struct igt_ktest *tst, const char *opts) { struct kmod_module *kunit_kmod; bool is_builtin; - int ret; struct ktap_test_results *results; struct ktap_test_results_element *temp; + int flags, ret; igt_skip_on_f(tst->kmsg < 0, "Could not open /dev/kmsg\n"); + flags = fcntl(tst->kmsg, F_GETFL, 0) & ~O_NONBLOCK; + igt_skip_on_f(fcntl(tst->kmsg, F_SETFL, flags) == -1, + "Could not set /dev/kmsg to blocking mode\n"); + igt_skip_on(lseek(tst->kmsg, 0, SEEK_END) < 0); igt_skip_on(kmod_module_new_from_name(kmod_ctx(), "kunit", &kunit_kmod)); diff --git a/lib/igt_ktap.c b/lib/igt_ktap.c index fe77b62680..165f6b2cce 100644 --- a/lib/igt_ktap.c +++ b/lib/igt_ktap.c @@ -59,20 +59,12 @@ static int log_to_end(enum igt_log_level level, int fd, while (*lend == '\0') { igt_log(IGT_LOG_DOMAIN, level, "%s", record); - while (read(fd, record, BUF_LEN) < 0) { - if (errno == EINTR) - return -2; - - if (errno == EPIPE) { + if (read(fd, record, BUF_LEN) < 0) { + if (errno == EPIPE) igt_warn("kmsg truncated: too many messages. You may want to increase log_buf_len in kmcdline\n"); - return -2; - } + else if (errno != EINTR) + igt_warn("an error occurred while reading kmsg: %m\n"); - if (errno == EAGAIN) - /* No records available */ - continue; - - igt_warn("kmsg truncated: unknown error (%m)\n"); return -2; } @@ -176,20 +168,12 @@ static int find_next_tap_subtest(int fd, char *record, char *test_name, bool is_ return -1; if (is_builtin) { - while (read(fd, record, BUF_LEN) < 0) { - if (errno == EINTR) - return -2; - - if (errno == EPIPE) { + if (read(fd, record, BUF_LEN) < 0) { + if (errno == EPIPE) igt_warn("kmsg truncated: too many messages. You may want to increase log_buf_len in kmcdline\n"); - return -2; - } + else if (errno != EINTR) + igt_warn("an error occurred while reading kmsg: %m\n"); - if (errno == EAGAIN) - /* No records available */ - continue; - - igt_warn("kmsg truncated: unknown error (%m)\n"); return -2; } } @@ -215,20 +199,12 @@ static int find_next_tap_subtest(int fd, char *record, char *test_name, bool is_ if (cutoff) cutoff[0] = '\0'; - while (read(fd, record, BUF_LEN) < 0) { - if (errno == EINTR) - return -2; - - if (errno == EPIPE) { + if (read(fd, record, BUF_LEN) < 0) { + if (errno == EPIPE) igt_warn("kmsg truncated: too many messages. You may want to increase log_buf_len in kmcdline\n"); - return -2; - } + else if (errno != EINTR) + igt_warn("unknown error reading kmsg (%m)\n"); - if (errno == EAGAIN) - /* No records available */ - continue; - - igt_warn("kmsg truncated: unknown error (%m)\n"); return -2; } @@ -365,20 +341,12 @@ static int parse_tap_level(int fd, char *base_test_name, int test_count, bool *f char base_test_name_for_next_level[BUF_LEN + 1]; for (int i = 0; i < test_count; i++) { - while (read(fd, record, BUF_LEN) < 0) { - if (errno == EINTR) - return -1; - - if (errno == EAGAIN) - /* No records available */ - continue; - - if (errno == EPIPE) { + if (read(fd, record, BUF_LEN) < 0) { + if (errno == EPIPE) igt_warn("kmsg truncated: too many messages. You may want to increase log_buf_len in kmcdline\n"); - return -1; - } + else if (errno != EINTR) + igt_warn("error reading kmsg (%m)\n"); - igt_warn("kmsg truncated: unknown error (%m)\n"); return -1; } @@ -506,18 +474,13 @@ igt_ktap_parser_start: test_name[0] = '\0'; test_name[BUF_LEN] = '\0'; - while (read(fd, record, BUF_LEN) < 0) { - if (errno == EAGAIN) - /* No records available */ - continue; - - if (errno == EINTR) - goto igt_ktap_parser_end; - - if (errno == EPIPE) { + if (read(fd, record, BUF_LEN) < 0) { + if (errno == EPIPE) igt_warn("kmsg truncated: too many messages. You may want to increase log_buf_len in kmcdline\n"); - goto igt_ktap_parser_end; - } + else if (errno != EINTR) + igt_warn("error reading kmsg (%m)\n"); + + goto igt_ktap_parser_end; } test_count = find_next_tap_subtest(fd, record, test_name, is_builtin);