From patchwork Mon Apr 25 19:00:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yosry Ahmed X-Patchwork-Id: 12826096 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A53EDC43217 for ; Mon, 25 Apr 2022 19:01:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244788AbiDYTEI (ORCPT ); Mon, 25 Apr 2022 15:04:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48844 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244798AbiDYTEH (ORCPT ); Mon, 25 Apr 2022 15:04:07 -0400 Received: from mail-pl1-x649.google.com (mail-pl1-x649.google.com [IPv6:2607:f8b0:4864:20::649]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 10B17E07E8 for ; Mon, 25 Apr 2022 12:01:01 -0700 (PDT) Received: by mail-pl1-x649.google.com with SMTP id g12-20020a170902740c00b0015d243ff163so1403205pll.19 for ; Mon, 25 Apr 2022 12:01:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=jNhmc3CPZ5vCVsb/llHs2xPQpQWQkNvnnQyZxpAVZvA=; b=Iq2S9Shz90p8NHXUzctrcXtVuymG0BHSMWdhf3g1aIk+jXNBHmBuLrOBkPz2g4i3wW I7e0S8dzX3XzREZmLBITiaxkxl465uGcVGpGess8no2z2MAudjeZ5DXw3Bxw73ZwGB7Q MRgm6I/dGRKXsHFripVwmfFPqfdFuclgGVwPjylXzWPgHqZNZPtB/1Jp2/oJ/W7F8y9S xGfsYuGC32TY9P82ZdD8i1tsMQF2qAPElU0/7vVYlioIFiFqD6K4zo+sVZzH9CF/FciX ais1AXji+6NbrGAuv46JxiDFpUDOZCEt5oQMPU1eKiljCUa03EJHxT2O52T/s7cWJYGy 3zbg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=jNhmc3CPZ5vCVsb/llHs2xPQpQWQkNvnnQyZxpAVZvA=; b=vvDReEFawvjI4V5WRKDKJ/+BbzMjYP3Vmnwxn7hADkM5zOa5l0YiMUJLNz3EaXaFDq 9AeKdvtIbbhtyxVw2gBxILyC33JLFfgka64Q0QiG/08qZOmWIR8yvDjspW9zoF/pkv6i IL6VfJz9L+/n2koyKUZH0HbVa6egJxp2aKxKSnYF8irL+ze8VEwaze0kne9AiOBDRgHC zALeca+4+KOh4frG76djk9jkfOQhILEUpXPywf5/rKmsnYoY4p65GeFV0lzmnYcGLc30 Rh0khLMPNno/gplohFs/YbpS0DeDvxX9IhC238PZjQvhtW8sykb/ViZdUU/wFayQTcBM cSeQ== X-Gm-Message-State: AOAM532CUXalxPuFJJb3t6VOqu/KXVfQSolAn3sNW0UTyYRNbY2tzI6E q2T2MWDrS8DmzNujB/lyu/JS0MFLqK5Slwka X-Google-Smtp-Source: ABdhPJx65fYn7YEk1pJGBjuWZR1gDqcxVKg0wWAyLHRkp/HuiCGSFGtSHC0vblXC2WzozjDBTDdEn4/m5NJEQ0y5 X-Received: from yosry.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:2327]) (user=yosryahmed job=sendgmr) by 2002:a17:90a:9105:b0:1d2:9e98:7e1e with SMTP id k5-20020a17090a910500b001d29e987e1emr1604034pjo.0.1650913260401; Mon, 25 Apr 2022 12:01:00 -0700 (PDT) Date: Mon, 25 Apr 2022 19:00:40 +0000 In-Reply-To: <20220425190040.2475377-1-yosryahmed@google.com> Message-Id: <20220425190040.2475377-5-yosryahmed@google.com> Mime-Version: 1.0 References: <20220425190040.2475377-1-yosryahmed@google.com> X-Mailer: git-send-email 2.36.0.rc2.479.g8af0fa9b8e-goog Subject: [PATCH v5 4/4] selftests: cgroup: add a selftest for memory.reclaim From: Yosry Ahmed To: Johannes Weiner , Michal Hocko , Shakeel Butt , Andrew Morton , Roman Gushchin Cc: David Rientjes , Tejun Heo , Zefan Li , Jonathan Corbet , Shuah Khan , Yu Zhao , Dave Hansen , Wei Xu , Greg Thelen , Chen Wandun , Vaibhav Jain , " =?utf-8?q?Michal_Koutn=C3=BD?= " , Tim Chen , cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, Yosry Ahmed Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Add a new test for memory.reclaim that verifies that the interface correctly reclaims memory as intended, from both anon and file pages. Signed-off-by: Yosry Ahmed Acked-by: Roman Gushchin Acked-by: David Rientjes --- .../selftests/cgroup/test_memcontrol.c | 106 ++++++++++++++++++ 1 file changed, 106 insertions(+) diff --git a/tools/testing/selftests/cgroup/test_memcontrol.c b/tools/testing/selftests/cgroup/test_memcontrol.c index f2ffb3a30194..a9c691fb94c0 100644 --- a/tools/testing/selftests/cgroup/test_memcontrol.c +++ b/tools/testing/selftests/cgroup/test_memcontrol.c @@ -760,6 +760,111 @@ static int test_memcg_max(const char *root) return ret; } +/* + * This test checks that memory.reclaim reclaims the given + * amount of memory (from both anon and file, if possible). + */ +static int test_memcg_reclaim(const char *root) +{ + int ret = KSFT_FAIL, fd, retries; + char *memcg; + long current, expected_usage, to_reclaim; + char buf[64]; + + memcg = cg_name(root, "memcg_test"); + if (!memcg) + goto cleanup; + + if (cg_create(memcg)) + goto cleanup; + + current = cg_read_long(memcg, "memory.current"); + if (current != 0) + goto cleanup; + + fd = get_temp_fd(); + if (fd < 0) + goto cleanup; + + cg_run_nowait(memcg, alloc_pagecache_50M_noexit, (void *)(long)fd); + + /* + * If swap is enabled, try to reclaim from both anon and file, else try + * to reclaim from file only. + */ + if (is_swap_enabled()) { + cg_run_nowait(memcg, alloc_anon_noexit, (void *) MB(50)); + expected_usage = MB(100); + } else + expected_usage = MB(50); + + /* + * Wait until current usage reaches the expected usage (or we run out of + * retries). + */ + retries = 5; + while (!values_close(cg_read_long(memcg, "memory.current"), + expected_usage, 10)) { + if (retries--) { + sleep(1); + continue; + } else { + fprintf(stderr, + "failed to allocate %ld for memcg reclaim test\n", + expected_usage); + goto cleanup; + } + } + + /* + * Reclaim until current reaches 30M, this makes sure we hit both anon + * and file if swap is enabled. + */ + retries = 5; + while (true) { + int err; + + current = cg_read_long(memcg, "memory.current"); + to_reclaim = current - MB(30); + + /* + * We only keep looping if we get EAGAIN, which means we could + * not reclaim the full amount. + */ + if (to_reclaim <= 0) + goto cleanup; + + + snprintf(buf, sizeof(buf), "%ld", to_reclaim); + err = cg_write(memcg, "memory.reclaim", buf); + if (!err) { + /* + * If writing succeeds, then the written amount should have been + * fully reclaimed (and maybe more). + */ + current = cg_read_long(memcg, "memory.current"); + if (!values_close(current, MB(30), 3) && current > MB(30)) + goto cleanup; + break; + } + + /* The kernel could not reclaim the full amount, try again. */ + if (err == -EAGAIN && retries--) + continue; + + /* We got an unexpected error or ran out of retries. */ + goto cleanup; + } + + ret = KSFT_PASS; +cleanup: + cg_destroy(memcg); + free(memcg); + close(fd); + + return ret; +} + static int alloc_anon_50M_check_swap(const char *cgroup, void *arg) { long mem_max = (long)arg; @@ -1263,6 +1368,7 @@ struct memcg_test { T(test_memcg_high), T(test_memcg_high_sync), T(test_memcg_max), + T(test_memcg_reclaim), T(test_memcg_oom_events), T(test_memcg_swap_max), T(test_memcg_sock),