From patchwork Thu Nov 30 19:40:22 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nhat Pham X-Patchwork-Id: 748857 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Qnf/To2n" Received: from mail-pf1-x42d.google.com (mail-pf1-x42d.google.com [IPv6:2607:f8b0:4864:20::42d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4EF6710FC; Thu, 30 Nov 2023 11:40:29 -0800 (PST) Received: by mail-pf1-x42d.google.com with SMTP id d2e1a72fcca58-6cdd405ca77so1355559b3a.0; Thu, 30 Nov 2023 11:40:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1701373229; x=1701978029; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=qpgmz+lE50DZaA/oBKT5EnJWyAwPJO9gmArvQZM8Xwo=; b=Qnf/To2n8Qz1u+nb9orWtBZ52QkfBM6wHdmRQ7hSyadWtAkEwn4tj9egxiL6aa8zei 78aN4CELh3HJsnlEpWSsDf0uPDk/abTDoMb5RFNw/k1XT1J/rZOphPamBx03Aojszr0z AGqSz22sHG5NDMrECqX8wpciHqDiigryon+6wzG1DbhlD/cOqflJ6XXAabA5AyeiKbW2 vBW3FLAaL4ICG32DKKngi4sJmVhDAd/IOZ6ntUiFTFAMQYC2J/uNB54w9YdYFrKYCc07 bHmuLEehbrnCzRyYb/+2rHE8vOlpsyp4vPkw2vg3Htg5bbJiRxJzRHGVuF8u0KasuCLu cQjg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701373229; x=1701978029; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=qpgmz+lE50DZaA/oBKT5EnJWyAwPJO9gmArvQZM8Xwo=; b=jDUjmGN11KeMhHuiHSnmAy5tYbDM1R+cZBkRVJKNcd+xmT3Oxkr73EJaO7mT5rCBDr xYgqJyf1kGsYTPpbQsnuZzcBNM/FJSlmPAy/ZAuXNjSDo3IBi9k7DgCqvNolY9SZzEC0 fMWqBBtCau8JC6P2wa65StzPvTe28J2iFP3scmfoMG8wdBFphIFA9TzM9OI+bYgNwfO5 uH91DXIbtRUvL2UfQga0sYjb7qxFAPIPWOcgmL7UO/VcgvgbdZUil/ouPLSWKH93zzNt MClo0rbRGbbR8Hc1HJkgvHl+zqpNVcMLfJfV01/YCjShcVOScIKcVLWbJ8cwCts6OcQW P3sw== X-Gm-Message-State: AOJu0YySlz/ZJFgfRI/59T1FS4RKqtGOtEZyvmR76eHBV35dtYh0735T CmkRWdlL0i+ghIH7yE3HSWM= X-Google-Smtp-Source: AGHT+IGYdyLqpZ865rWuypFMfdyVFVpmYSTqMroZfbGqbPl/REmPVsjsfgA/flekoxBz7Bf3NKxULw== X-Received: by 2002:a05:6a20:a103:b0:189:11e8:6237 with SMTP id q3-20020a056a20a10300b0018911e86237mr27078069pzk.51.1701373228536; Thu, 30 Nov 2023 11:40:28 -0800 (PST) Received: from localhost (fwdproxy-prn-000.fbsv.net. [2a03:2880:ff::face:b00c]) by smtp.gmail.com with ESMTPSA id x67-20020a626346000000b006be0fb89ac2sm1630852pfb.197.2023.11.30.11.40.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 30 Nov 2023 11:40:28 -0800 (PST) From: Nhat Pham To: akpm@linux-foundation.org Cc: hannes@cmpxchg.org, cerasuolodomenico@gmail.com, yosryahmed@google.com, sjenning@redhat.com, ddstreet@ieee.org, vitaly.wool@konsulko.com, mhocko@kernel.org, roman.gushchin@linux.dev, shakeelb@google.com, muchun.song@linux.dev, chrisl@kernel.org, linux-mm@kvack.org, kernel-team@meta.com, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, shuah@kernel.org Subject: [PATCH v8 5/6] selftests: cgroup: update per-memcg zswap writeback selftest Date: Thu, 30 Nov 2023 11:40:22 -0800 Message-Id: <20231130194023.4102148-6-nphamcs@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231130194023.4102148-1-nphamcs@gmail.com> References: <20231130194023.4102148-1-nphamcs@gmail.com> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Domenico Cerasuolo The memcg-zswap self test is updated to adjust to the behavior change implemented by commit 87730b165089 ("zswap: make shrinking memcg-aware"), where zswap performs writeback for specific memcg. Signed-off-by: Domenico Cerasuolo Signed-off-by: Nhat Pham Acked-by: Chris Li (Google) --- tools/testing/selftests/cgroup/test_zswap.c | 74 ++++++++++++++------- 1 file changed, 50 insertions(+), 24 deletions(-) diff --git a/tools/testing/selftests/cgroup/test_zswap.c b/tools/testing/selftests/cgroup/test_zswap.c index c99d2adaca3f..47fdaa146443 100644 --- a/tools/testing/selftests/cgroup/test_zswap.c +++ b/tools/testing/selftests/cgroup/test_zswap.c @@ -50,9 +50,9 @@ static int get_zswap_stored_pages(size_t *value) return read_int("/sys/kernel/debug/zswap/stored_pages", value); } -static int get_zswap_written_back_pages(size_t *value) +static int get_cg_wb_count(const char *cg) { - return read_int("/sys/kernel/debug/zswap/written_back_pages", value); + return cg_read_key_long(cg, "memory.stat", "zswp_wb"); } static long get_zswpout(const char *cgroup) @@ -73,6 +73,24 @@ static int allocate_bytes(const char *cgroup, void *arg) return 0; } +static char *setup_test_group_1M(const char *root, const char *name) +{ + char *group_name = cg_name(root, name); + + if (!group_name) + return NULL; + if (cg_create(group_name)) + goto fail; + if (cg_write(group_name, "memory.max", "1M")) { + cg_destroy(group_name); + goto fail; + } + return group_name; +fail: + free(group_name); + return NULL; +} + /* * Sanity test to check that pages are written into zswap. */ @@ -117,43 +135,51 @@ static int test_zswap_usage(const char *root) /* * When trying to store a memcg page in zswap, if the memcg hits its memory - * limit in zswap, writeback should not be triggered. - * - * This was fixed with commit 0bdf0efa180a("zswap: do not shrink if cgroup may - * not zswap"). Needs to be revised when a per memcg writeback mechanism is - * implemented. + * limit in zswap, writeback should affect only the zswapped pages of that + * memcg. */ static int test_no_invasive_cgroup_shrink(const char *root) { - size_t written_back_before, written_back_after; int ret = KSFT_FAIL; - char *test_group; + size_t control_allocation_size = MB(10); + char *control_allocation, *wb_group = NULL, *control_group = NULL; /* Set up */ - test_group = cg_name(root, "no_shrink_test"); - if (!test_group) - goto out; - if (cg_create(test_group)) + wb_group = setup_test_group_1M(root, "per_memcg_wb_test1"); + if (!wb_group) + return KSFT_FAIL; + if (cg_write(wb_group, "memory.zswap.max", "10K")) goto out; - if (cg_write(test_group, "memory.max", "1M")) + control_group = setup_test_group_1M(root, "per_memcg_wb_test2"); + if (!control_group) goto out; - if (cg_write(test_group, "memory.zswap.max", "10K")) + + /* Push some test_group2 memory into zswap */ + if (cg_enter_current(control_group)) goto out; - if (get_zswap_written_back_pages(&written_back_before)) + control_allocation = malloc(control_allocation_size); + for (int i = 0; i < control_allocation_size; i += 4095) + control_allocation[i] = 'a'; + if (cg_read_key_long(control_group, "memory.stat", "zswapped") < 1) goto out; - /* Allocate 10x memory.max to push memory into zswap */ - if (cg_run(test_group, allocate_bytes, (void *)MB(10))) + /* Allocate 10x memory.max to push wb_group memory into zswap and trigger wb */ + if (cg_run(wb_group, allocate_bytes, (void *)MB(10))) goto out; - /* Verify that no writeback happened because of the memcg allocation */ - if (get_zswap_written_back_pages(&written_back_after)) - goto out; - if (written_back_after == written_back_before) + /* Verify that only zswapped memory from gwb_group has been written back */ + if (get_cg_wb_count(wb_group) > 0 && get_cg_wb_count(control_group) == 0) ret = KSFT_PASS; out: - cg_destroy(test_group); - free(test_group); + cg_enter_current(root); + if (control_group) { + cg_destroy(control_group); + free(control_group); + } + cg_destroy(wb_group); + free(wb_group); + if (control_allocation) + free(control_allocation); return ret; }