From patchwork Tue May 21 07:43:56 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dev Jain X-Patchwork-Id: 13668974 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 253A9C25B74 for ; Tue, 21 May 2024 07:44:27 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5A1BC6B008A; Tue, 21 May 2024 03:44:26 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5521F6B008C; Tue, 21 May 2024 03:44:26 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 441166B0092; Tue, 21 May 2024 03:44:26 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 292606B008A for ; 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dmarc=pass (policy=none) header.from=arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1716277464; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=uHco4/l+DIy5bStEcsrRUhdcO6HXBj/kpjTeF+RtgSc=; b=g5ScWhbH2X7vCi95k00idKujBfjegUjqLJ7fE4T5BbKKFy9WfCjetz15Ht2Pij49jlz1bw zQ5XZA8KqdiBgbJe7Bf9gqvD+f5EshMIrcp2wqAMIBwbRLPQ4rmfirLc3ekydYVjdxsqpd 82CmbTKd84k4Zk748vsH2IOTVsdl2AA= Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 4435CFEC; Tue, 21 May 2024 00:44:47 -0700 (PDT) Received: from e116581.blr.arm.com (e116581.arm.com [10.162.42.16]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id DB03C3F641; Tue, 21 May 2024 00:44:19 -0700 (PDT) From: Dev Jain To: akpm@linux-foundation.org, shuah@kernel.org Cc: linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Anshuman.Khandual@arm.com, sjayaram@akamai.com, Dev Jain , stable@vger.kernel.org Subject: [PATCH v2 1/3] selftests/mm: compaction_test: Fix bogus test success on Aarch64 Date: Tue, 21 May 2024 13:13:56 +0530 Message-Id: <20240521074358.675031-2-dev.jain@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240521074358.675031-1-dev.jain@arm.com> References: <20240521074358.675031-1-dev.jain@arm.com> MIME-Version: 1.0 X-Rspamd-Queue-Id: 097CD8000F X-Rspam-User: X-Rspamd-Server: rspam12 X-Stat-Signature: jcyn54xush5pqnj8cn45ieexjzpi37yi X-HE-Tag: 1716277463-566777 X-HE-Meta: U2FsdGVkX1+yzNMcp9j6v4jyk2jvB0NnmigouhzRi4XjiXp5rTAblXyT+aURuxdv4fiHStZ5mAMBhBfX4VVtS/D9nky1SzSWNm74LmzuDO2GaZormDHOh0Wp6H8q7tqvQFqnH+aRcemQpJE+0DQd9DtsqovgcbZM2w8A2jPOzuIzYGL8cb7OV5vGnZyZYNRwLHIUe14+1M+5MlPgMY2sDR7HvLGJOvyn9YjmK1xB7tZ4QIH5jbXqlAZW9hN8FsbpjvPpJ6DvUy67yK2tt/8XjHYvan8M+JE5MpSXDdK7N0i3mosv/+IXBOHvWta+j2Mm0huR6sK2GFhMh6HwDsEGLp0zNocsw5wWlOwVbB7w4hueVQjpxDtjVpE+IaBSqrgljNlcTYm9DUANRsABMHuP67wTMs6AsuIa8rYGcuWzfiwehUE9sCXWY5wnYt31Fw63IbvNLUKf5ZhRb9M4GkKvryuIGigDxNizNfQBdbR0tfqsvN3uuSazuXJSVdt+hjxYrYA4WbMDJATu7Yx9raBpWmMLkX4zpGUrL9Xg8/KYP9uQ8hf1uE82TMv6ix2lWuJOrOKSb2u9xfLy+tthzASdec0rERGyzM579uLPMiNXopa7IY6V6ycSWZbuzLasrlQAXrrBvTnVJ9o8ohLs1sLR1AXc7knV1ljEKHi8Dr2bplOVxXzXv5nG8nPRqvpZ+z7/Y/LOkemlovIQnGVH/qRosQWx45A8iErSTB4ttpxq2ukU6v8XzASgiStAdtI86sy329jRsdEQ56FnwWx7Sb2orrXno/HWDWP1ogUhCJE7cDUQPDl3nnPtkDzn/S4NjxMGt4ttb2FoKvsSMlYmz93lqY19uERU1tnuLHybkwnRembGpEdJzYgvIz0P2+Zh8LeeM1Ptns9OcHtaRBVRJ8H0So+Nr+l8GQ6o//feiJ57bipXWleRYGRNksbp+T+qMXOvz1eP2tVQJHEZNaiIUMU 2YG21+M4 1ri76zdgcb8A2W3mHqpZD9XotZrpk1ZeSz2+sTapxw3mLXIvW0SeGIWdVMP6ctgPHXo8qqr+zFyAjIdeG7MWfm3fGVXnhHxAlUw4aIo7ucmSlV4SP2pw6di7kL8SrHJZI5UdmC2igZNSKHLikKoLdknNGi9IwQQFhVPYDYFSNTrzCVTr2XvJAZN4hwujbt/tXEyPmQ3k8ujWbtY6f7SzyvZbZofVUaUE85LTkWK9Tm/20QQmfSK0jlbbAUxxuSKS04V8KPQpZaxEntdY= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Currently, if at runtime we are not able to allocate a huge page, the test will trivially pass on Aarch64 due to no exception being raised on division by zero while computing compaction_index. Fix that by checking for nr_hugepages == 0. Anyways, in general, avoid a division by zero by exiting the program beforehand. While at it, fix a typo, and handle the case where the number of hugepages may overflow an integer. Changes in v2: - Combine with this series, handle unsigned long number of hugepages v1: - https://lore.kernel.org/all/20240513082842.4117782-1-dev.jain@arm.com/ Fixes: bd67d5c15cc1 ("Test compaction of mlocked memory") Cc: stable@vger.kernel.org Signed-off-by: Dev Jain --- tools/testing/selftests/mm/compaction_test.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/tools/testing/selftests/mm/compaction_test.c b/tools/testing/selftests/mm/compaction_test.c index 4f42eb7d7636..0b249a06a60b 100644 --- a/tools/testing/selftests/mm/compaction_test.c +++ b/tools/testing/selftests/mm/compaction_test.c @@ -82,12 +82,13 @@ int prereq(void) return -1; } -int check_compaction(unsigned long mem_free, unsigned int hugepage_size) +int check_compaction(unsigned long mem_free, unsigned long hugepage_size) { + unsigned long nr_hugepages_ul; int fd, ret = -1; int compaction_index = 0; - char initial_nr_hugepages[10] = {0}; - char nr_hugepages[10] = {0}; + char initial_nr_hugepages[20] = {0}; + char nr_hugepages[20] = {0}; /* We want to test with 80% of available memory. Else, OOM killer comes in to play */ @@ -134,7 +135,12 @@ int check_compaction(unsigned long mem_free, unsigned int hugepage_size) /* We should have been able to request at least 1/3 rd of the memory in huge pages */ - compaction_index = mem_free/(atoi(nr_hugepages) * hugepage_size); + nr_hugepages_ul = strtoul(nr_hugepages, NULL, 10); + if (!nr_hugepages_ul) { + ksft_print_msg("ERROR: No memory is available as huge pages\n"); + goto close_fd; + } + compaction_index = mem_free/(nr_hugepages_ul * hugepage_size); lseek(fd, 0, SEEK_SET); @@ -145,11 +151,11 @@ int check_compaction(unsigned long mem_free, unsigned int hugepage_size) goto close_fd; } - ksft_print_msg("Number of huge pages allocated = %d\n", - atoi(nr_hugepages)); + ksft_print_msg("Number of huge pages allocated = %lu\n", + nr_hugepages_ul); if (compaction_index > 3) { - ksft_print_msg("ERROR: Less that 1/%d of memory is available\n" + ksft_print_msg("ERROR: Less than 1/%d of memory is available\n" "as huge pages\n", compaction_index); goto close_fd; } From patchwork Tue May 21 07:43:57 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dev Jain X-Patchwork-Id: 13668975 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4A6E6C25B74 for ; Tue, 21 May 2024 07:44:30 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C0A236B008C; Tue, 21 May 2024 03:44:29 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id BBA3B6B0092; Tue, 21 May 2024 03:44:29 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AD07E6B0093; Tue, 21 May 2024 03:44:29 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 913356B008C for ; 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Tue, 21 May 2024 00:44:23 -0700 (PDT) From: Dev Jain To: akpm@linux-foundation.org, shuah@kernel.org Cc: linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Anshuman.Khandual@arm.com, sjayaram@akamai.com, Dev Jain , stable@vger.kernel.org Subject: [PATCH v2 2/3] selftests/mm: compaction_test: Fix incorrect write of zero to nr_hugepages Date: Tue, 21 May 2024 13:13:57 +0530 Message-Id: <20240521074358.675031-3-dev.jain@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240521074358.675031-1-dev.jain@arm.com> References: <20240521074358.675031-1-dev.jain@arm.com> MIME-Version: 1.0 X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: CFF90140019 X-Rspam-User: X-Stat-Signature: ztoc5n8fwzbcu4xgfrzou9qjwwcrype6 X-HE-Tag: 1716277467-567167 X-HE-Meta: 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 VTMpGmyR nF8Z0jlySAIQQDy2hFNbU+4ptlkE9ee1pCKcxllXF+v0Y6KDDCwt4jY55rZZ8cVYU4A/aKZPrpN9BgiUsWwYihaWtyCDrs9/VOIi4x82hhF1W+TYlymK/vnP/dEX6286R0P4+snQqVZFi0l/bSuB0QVPQypzMG6tIvt5WrfvupHrjkQr4NOSEsc8BJm8Em7s5XfwBCM9KSNmvnDEjdiJS37/DGPCsWLsig7ke9CZulh13AVGg3ojsJOrY1cGqatS4Ry2ZPhLS8WW/8uE= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Currently, the test tries to set nr_hugepages to zero, but that is not actually done because the file offset is not reset after read(). Fix that using lseek(). Fixes: bd67d5c15cc1 ("Test compaction of mlocked memory") Cc: stable@vger.kernel.org Signed-off-by: Dev Jain --- tools/testing/selftests/mm/compaction_test.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/testing/selftests/mm/compaction_test.c b/tools/testing/selftests/mm/compaction_test.c index 0b249a06a60b..5e9bd1da9370 100644 --- a/tools/testing/selftests/mm/compaction_test.c +++ b/tools/testing/selftests/mm/compaction_test.c @@ -108,6 +108,8 @@ int check_compaction(unsigned long mem_free, unsigned long hugepage_size) goto close_fd; } + lseek(fd, 0, SEEK_SET); + /* Start with the initial condition of 0 huge pages*/ if (write(fd, "0", sizeof(char)) != sizeof(char)) { ksft_print_msg("Failed to write 0 to /proc/sys/vm/nr_hugepages: %s\n", From patchwork Tue May 21 07:43:58 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dev Jain X-Patchwork-Id: 13668976 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5E91FC25B74 for ; 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s=arc-20220608; d=hostedemail.com; t=1716277472; a=rsa-sha256; cv=none; b=jdwIM5lFc2TFOnCZlLXxMNFxktKLNJTkZydSyUJj0qDGYbjmh1PfYtGJ6LFNZ7BkGLp+3t GQO6QCP+NdbmWbJyRFasilOE9myyC/luo59CiSLSrm6zbH2H7ZgCBL4psLHjv27LZRH31R J7Y3NCu+H/5ppdSQzF4ikaqTYejnbTw= Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id ED9D8DA7; Tue, 21 May 2024 00:44:54 -0700 (PDT) Received: from e116581.blr.arm.com (e116581.arm.com [10.162.42.16]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id BF2A93F641; Tue, 21 May 2024 00:44:27 -0700 (PDT) From: Dev Jain To: akpm@linux-foundation.org, shuah@kernel.org Cc: linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Anshuman.Khandual@arm.com, sjayaram@akamai.com, Dev Jain , stable@vger.kernel.org Subject: [PATCH v2 3/3] selftests/mm: compaction_test: Fix bogus test success and reduce probability of OOM-killer invocation Date: Tue, 21 May 2024 13:13:58 +0530 Message-Id: <20240521074358.675031-4-dev.jain@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240521074358.675031-1-dev.jain@arm.com> References: <20240521074358.675031-1-dev.jain@arm.com> MIME-Version: 1.0 X-Stat-Signature: 8kzbx8cpj9nygdy543xsxx6jqukcoean X-Rspamd-Queue-Id: CD3C84000A X-Rspam-User: X-Rspamd-Server: rspam10 X-HE-Tag: 1716277471-826131 X-HE-Meta: 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 pQcHbu6G qtmH3ewWlM5uR6E+eXoZfL8J4wBJAKd9mbW/RZddyhkHVVCZ1tJi/tILe+KlklO1FgMdW9IqAG8JEqgi8GvD77yYE2QSGFBhmoI3NXJsu9TjENTuHhmLXnFTdYKL63RbewR8eOA5AYHVZG4z4yI0MYFfD9KSqavXZssg2WPbkeCLXvfJlPzGMNqgFK20JBNvn+7lqxMjG1/NKFJHd/wybweCIjcaO1OsdA3hHaOMcFn/kySKNPtn21tHngeBotAKahPivUrsqGKI1EY8= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Reset nr_hugepages to zero before the start of the test. If a non-zero number of hugepages is already set before the start of the test, the following problems arise: - The probability of the test getting OOM-killed increases. Proof: The test wants to run on 80% of available memory to prevent OOM-killing (see original code comments). Let the value of mem_free at the start of the test, when nr_hugepages = 0, be x. In the other case, when nr_hugepages > 0, let the memory consumed by hugepages be y. In the former case, the test operates on 0.8 * x of memory. In the latter, the test operates on 0.8 * (x - y) of memory, with y already filled, hence, memory consumed is y + 0.8 * (x - y) = 0.8 * x + 0.2 * y > 0.8 * x. Q.E.D - The probability of a bogus test success increases. Proof: Let the memory consumed by hugepages be greater than 25% of x, with x and y defined as above. The definition of compaction_index is c_index = (x - y)/z where z is the memory consumed by hugepages after trying to increase them again. In check_compaction(), we set the number of hugepages to zero, and then increase them back; the probability that they will be set back to consume at least y amount of memory again is very high (since there is not much delay between the two attempts of changing nr_hugepages). Hence, z >= y > (x/4) (by the 25% assumption). Therefore, c_index = (x - y)/z <= (x - y)/y = x/y - 1 < 4 - 1 = 3 hence, c_index can always be forced to be less than 3, thereby the test succeeding always. Q.E.D Changes in v2: - Handle unsigned long number of hugepages v1: - https://lore.kernel.org/all/20240515093633.54814-3-dev.jain@arm.com/ NOTE: This patch depends on the previous one. Fixes: bd67d5c15cc1 ("Test compaction of mlocked memory") Cc: stable@vger.kernel.org Signed-off-by: Dev Jain --- tools/testing/selftests/mm/compaction_test.c | 71 ++++++++++++++------ 1 file changed, 49 insertions(+), 22 deletions(-) diff --git a/tools/testing/selftests/mm/compaction_test.c b/tools/testing/selftests/mm/compaction_test.c index 5e9bd1da9370..e140558e6f53 100644 --- a/tools/testing/selftests/mm/compaction_test.c +++ b/tools/testing/selftests/mm/compaction_test.c @@ -82,13 +82,16 @@ int prereq(void) return -1; } -int check_compaction(unsigned long mem_free, unsigned long hugepage_size) +int check_compaction(unsigned long mem_free, unsigned long hugepage_size, + unsigned long initial_nr_hugepages) { unsigned long nr_hugepages_ul; int fd, ret = -1; int compaction_index = 0; - char initial_nr_hugepages[20] = {0}; char nr_hugepages[20] = {0}; + char init_nr_hugepages[20] = {0}; + + sprintf(init_nr_hugepages, "%lu", initial_nr_hugepages); /* We want to test with 80% of available memory. Else, OOM killer comes in to play */ @@ -102,23 +105,6 @@ int check_compaction(unsigned long mem_free, unsigned long hugepage_size) goto out; } - if (read(fd, initial_nr_hugepages, sizeof(initial_nr_hugepages)) <= 0) { - ksft_print_msg("Failed to read from /proc/sys/vm/nr_hugepages: %s\n", - strerror(errno)); - goto close_fd; - } - - lseek(fd, 0, SEEK_SET); - - /* Start with the initial condition of 0 huge pages*/ - if (write(fd, "0", sizeof(char)) != sizeof(char)) { - ksft_print_msg("Failed to write 0 to /proc/sys/vm/nr_hugepages: %s\n", - strerror(errno)); - goto close_fd; - } - - lseek(fd, 0, SEEK_SET); - /* Request a large number of huge pages. The Kernel will allocate as much as it can */ if (write(fd, "100000", (6*sizeof(char))) != (6*sizeof(char))) { @@ -146,8 +132,8 @@ int check_compaction(unsigned long mem_free, unsigned long hugepage_size) lseek(fd, 0, SEEK_SET); - if (write(fd, initial_nr_hugepages, strlen(initial_nr_hugepages)) - != strlen(initial_nr_hugepages)) { + if (write(fd, init_nr_hugepages, strlen(init_nr_hugepages)) + != strlen(init_nr_hugepages)) { ksft_print_msg("Failed to write value to /proc/sys/vm/nr_hugepages: %s\n", strerror(errno)); goto close_fd; @@ -171,6 +157,41 @@ int check_compaction(unsigned long mem_free, unsigned long hugepage_size) return ret; } +int set_zero_hugepages(unsigned long *initial_nr_hugepages) +{ + int fd, ret = -1; + char nr_hugepages[20] = {0}; + + fd = open("/proc/sys/vm/nr_hugepages", O_RDWR | O_NONBLOCK); + if (fd < 0) { + ksft_print_msg("Failed to open /proc/sys/vm/nr_hugepages: %s\n", + strerror(errno)); + goto out; + } + if (read(fd, nr_hugepages, sizeof(nr_hugepages)) <= 0) { + ksft_print_msg("Failed to read from /proc/sys/vm/nr_hugepages: %s\n", + strerror(errno)); + goto close_fd; + } + + lseek(fd, 0, SEEK_SET); + + /* Start with the initial condition of 0 huge pages */ + if (write(fd, "0", sizeof(char)) != sizeof(char)) { + ksft_print_msg("Failed to write 0 to /proc/sys/vm/nr_hugepages: %s\n", + strerror(errno)); + goto close_fd; + } + + *initial_nr_hugepages = strtoul(nr_hugepages, NULL, 10); + ret = 0; + + close_fd: + close(fd); + + out: + return ret; +} int main(int argc, char **argv) { @@ -181,6 +202,7 @@ int main(int argc, char **argv) unsigned long mem_free = 0; unsigned long hugepage_size = 0; long mem_fragmentable_MB = 0; + unsigned long initial_nr_hugepages; ksft_print_header(); @@ -189,6 +211,10 @@ int main(int argc, char **argv) ksft_set_plan(1); + /* Start the test without hugepages reducing mem_free */ + if (set_zero_hugepages(&initial_nr_hugepages)) + ksft_exit_fail(); + lim.rlim_cur = RLIM_INFINITY; lim.rlim_max = RLIM_INFINITY; if (setrlimit(RLIMIT_MEMLOCK, &lim)) @@ -232,7 +258,8 @@ int main(int argc, char **argv) entry = entry->next; } - if (check_compaction(mem_free, hugepage_size) == 0) + if (check_compaction(mem_free, hugepage_size, + initial_nr_hugepages) == 0) ksft_exit_pass(); ksft_exit_fail();