From mboxrd@z Thu Jan 1 00:00:00 1970 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 52473C46CA1 for ; Mon, 18 Sep 2023 11:35:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241262AbjIRLfY (ORCPT ); Mon, 18 Sep 2023 07:35:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33076 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241800AbjIRLfU (ORCPT ); Mon, 18 Sep 2023 07:35:20 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 044DC11C; Mon, 18 Sep 2023 04:33:49 -0700 (PDT) Received: from kwepemi500008.china.huawei.com (unknown [172.30.72.54]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4Rq2dj1WCLzNncT; Mon, 18 Sep 2023 19:30:01 +0800 (CST) Received: from [10.67.109.254] (10.67.109.254) by kwepemi500008.china.huawei.com (7.221.188.139) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Mon, 18 Sep 2023 19:33:46 +0800 Message-ID: Date: Mon, 18 Sep 2023 19:33:45 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.2.0 Subject: Re: [PATCH v2 1/2] mm/damon/core-test: Fix memory leak in damon_new_region() Content-Language: en-US To: SeongJae Park CC: , , , , , , , References: <20230918110009.78365-1-sj@kernel.org> From: Ruan Jinjie In-Reply-To: <20230918110009.78365-1-sj@kernel.org> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.67.109.254] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To kwepemi500008.china.huawei.com (7.221.188.139) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2023/9/18 19:00, SeongJae Park wrote: > Hi Jinjie, > > On Mon, 18 Sep 2023 15:47:58 +0800 Jinjie Ruan wrote: > >> When CONFIG_DAMON_KUNIT_TEST=y and making CONFIG_DEBUG_KMEMLEAK=y >> and CONFIG_DEBUG_KMEMLEAK_AUTO_SCAN=y, the below memory leak is detected. >> >> The damon_region which is allocated by kmem_cache_alloc() in >> damon_new_region() in damon_test_regions() and >> damon_test_update_monitoring_result() are not freed. So use >> damon_free_region() to free it. > > Nit. This patch is not directly adding use of damon_free_region() but replaces > damon_del_region() call with damon_destroy_region(), so that it calls both > damon_del_region() and damon_free_region(). > > I think this part might better to be re-written? OK. Thank you! > >> After applying this patch, the following >> memory leak is never detected. >> >> unreferenced object 0xffff2b49c3edc000 (size 56): >> comm "kunit_try_catch", pid 338, jiffies 4294895280 (age 557.084s) >> hex dump (first 32 bytes): >> 01 00 00 00 00 00 00 00 02 00 00 00 00 00 00 00 ................ >> 00 00 00 00 00 00 00 00 00 00 00 00 49 2b ff ff ............I+.. >> backtrace: >> [<0000000088e71769>] slab_post_alloc_hook+0xb8/0x368 >> [<00000000b528f67c>] kmem_cache_alloc+0x168/0x284 >> [<000000008603f022>] damon_new_region+0x28/0x54 >> [<00000000a3b8c64e>] damon_test_regions+0x38/0x270 >> [<00000000559c4801>] kunit_try_run_case+0x50/0xac >> [<000000003932ed49>] kunit_generic_run_threadfn_adapter+0x20/0x2c >> [<000000003c3e9211>] kthread+0x124/0x130 >> [<0000000028f85bdd>] ret_from_fork+0x10/0x20 >> unreferenced object 0xffff2b49c5b20000 (size 56): >> comm "kunit_try_catch", pid 354, jiffies 4294895304 (age 556.988s) >> hex dump (first 32 bytes): >> 03 00 00 00 00 00 00 00 07 00 00 00 00 00 00 00 ................ >> 00 00 00 00 00 00 00 00 96 00 00 00 49 2b ff ff ............I+.. >> backtrace: >> [<0000000088e71769>] slab_post_alloc_hook+0xb8/0x368 >> [<00000000b528f67c>] kmem_cache_alloc+0x168/0x284 >> [<000000008603f022>] damon_new_region+0x28/0x54 >> [<00000000ca019f80>] damon_test_update_monitoring_result+0x18/0x34 >> [<00000000559c4801>] kunit_try_run_case+0x50/0xac >> [<000000003932ed49>] kunit_generic_run_threadfn_adapter+0x20/0x2c >> [<000000003c3e9211>] kthread+0x124/0x130 >> [<0000000028f85bdd>] ret_from_fork+0x10/0x20 >> >> Fixes: 17ccae8bb5c9 ("mm/damon: add kunit tests") >> Fixes: f4c978b6594b ("mm/damon/core-test: add a test for damon_update_monitoring_results()") >> Signed-off-by: Jinjie Ruan > > Other than the above trivial nit, > > Reviewed-by: SeongJae Park > >> --- >> v2: >> - Replace the damon_del_region() with damon_destroy_region() rather than >> calling damon_free_region(). >> - Update the commit message. > > And thank you for making the changes. > > > Thanks, > SJ > >> --- >> mm/damon/core-test.h | 4 +++- >> 1 file changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/mm/damon/core-test.h b/mm/damon/core-test.h >> index 79f1f12e0dd5..3959be35b901 100644 >> --- a/mm/damon/core-test.h >> +++ b/mm/damon/core-test.h >> @@ -30,7 +30,7 @@ static void damon_test_regions(struct kunit *test) >> damon_add_region(r, t); >> KUNIT_EXPECT_EQ(test, 1u, damon_nr_regions(t)); >> >> - damon_del_region(r, t); >> + damon_destroy_region(r, t); >> KUNIT_EXPECT_EQ(test, 0u, damon_nr_regions(t)); >> >> damon_free_target(t); >> @@ -321,6 +321,8 @@ static void damon_test_update_monitoring_result(struct kunit *test) >> damon_update_monitoring_result(r, &old_attrs, &new_attrs); >> KUNIT_EXPECT_EQ(test, r->nr_accesses, 150); >> KUNIT_EXPECT_EQ(test, r->age, 20); >> + >> + damon_free_region(r); >> } >> >> static void damon_test_set_attrs(struct kunit *test) >> -- >> 2.34.1 >> >>