From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from madrid.collaboradmins.com (madrid.collaboradmins.com [46.235.227.194]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B59F23F8EE for ; Wed, 10 Jan 2024 10:15:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b="hS4mD/5b" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1704881732; bh=0bJLXu0DBAoJ0i9wVZaWcD3g7PAFELQ/me31lacb4uI=; h=Date:Cc:Subject:To:References:From:In-Reply-To:From; b=hS4mD/5bm9fU1BHvnNtYHMtTM3M6ohBF5sPP3i+5OvaaXJJ+IAQoAaR2/k6JmRWWO vQrRRcj2zGFDQA7DGTKaiYaq4YE55VKiDtK8JdO7sqzQC22VMN1cTP+Mw7DdsyEtdX fcHOr/2ujarZYPZ/qCcuj61M4pIPhnLUlMQCZa4QE8+JZUcOJpUXP5BYhBej2lRzSd BqHJbXkzJU4R4uFRhyZ34ZRGKrBBaAZGwvQr8BtWFcywN1VrR1vrR3SdKHicawFi3j drhzEdoRglrwXdZlgT9pfM8ua3G7jDCSToPiMqI1l5byUcrCmTO4NdWINUmhbPmTvP xZRx4sb58YnoQ== Received: from [100.96.234.34] (cola.collaboradmins.com [195.201.22.229]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: usama.anjum) by madrid.collaboradmins.com (Postfix) with ESMTPSA id 2B44A37813B9; Wed, 10 Jan 2024 10:15:27 +0000 (UTC) Message-ID: <079335ab-190f-41f7-b832-6ffe7528fd8b@collabora.com> Date: Wed, 10 Jan 2024 15:15:34 +0500 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Cc: Muhammad Usama Anjum , linmiaohe@huawei.com, mike.kravetz@oracle.com, naoya.horiguchi@nec.com, akpm@linux-foundation.org, songmuchun@bytedance.com, shy828301@gmail.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, jthoughton@google.com, "kernel@collabora.com" , "Matthew Wilcox (Oracle)" , Mike Kravetz , Muchun Song Subject: Re: [PATCH v4 4/4] selftests/mm: add tests for HWPOISON hugetlbfs read Content-Language: en-US To: Jiaqi Yan , Sidhartha Kumar References: <20230713001833.3778937-1-jiaqiyan@google.com> <20230713001833.3778937-5-jiaqiyan@google.com> From: Muhammad Usama Anjum In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 1/10/24 11:49 AM, Muhammad Usama Anjum wrote: > On 1/6/24 2:13 AM, Jiaqi Yan wrote: >> On Thu, Jan 4, 2024 at 10:27 PM Muhammad Usama Anjum >> wrote: >>> >>> Hi, >>> >>> I'm trying to convert this test to TAP as I think the failures sometimes go >>> unnoticed on CI systems if we only depend on the return value of the >>> application. I've enabled the following configurations which aren't already >>> present in tools/testing/selftests/mm/config: >>> CONFIG_MEMORY_FAILURE=y >>> CONFIG_HWPOISON_INJECT=m >>> >>> I'll send a patch to add these configs later. Right now I'm trying to >>> investigate the failure when we are trying to inject the poison page by >>> madvise(MADV_HWPOISON). I'm getting device busy every single time. The test >>> fails as it doesn't expect any business for the hugetlb memory. I'm not >>> sure if the poison handling code has issues or test isn't robust enough. >>> >>> ./hugetlb-read-hwpoison >>> Write/read chunk size=0x800 >>> ... HugeTLB read regression test... >>> ... ... expect to read 0x200000 bytes of data in total >>> ... ... actually read 0x200000 bytes of data in total >>> ... HugeTLB read regression test...TEST_PASSED >>> ... HugeTLB read HWPOISON test... >>> [ 9.280854] Injecting memory failure for pfn 0x102f01 at process virtual >>> address 0x7f28ec101000 >>> [ 9.282029] Memory failure: 0x102f01: huge page still referenced by 511 >>> users >>> [ 9.282987] Memory failure: 0x102f01: recovery action for huge page: Failed >>> ... !!! MADV_HWPOISON failed: Device or resource busy >>> ... HugeTLB read HWPOISON test...TEST_FAILED >>> >>> I'm testing on v6.7-rc8. Not sure if this was working previously or not. >> >> Thanks for reporting this, Usama! >> >> I am also able to repro MADV_HWPOISON failure at "501a06fe8e4c >> (akpm/mm-stable, mm-stable) zswap: memcontrol: implement zswap >> writeback disabling." >> >> Then I checked out the earliest commit "ba91e7e5d15a (HEAD -> Base) >> selftests/mm: add tests for HWPOISON hugetlbfs read". The >> MADV_HWPOISON injection works and and the test passes: >> >> ... HugeTLB read HWPOISON test... >> ... ... expect to read 0x101000 bytes of data in total >> ... !!! read failed: Input/output error >> ... ... actually read 0x101000 bytes of data in total >> ... HugeTLB read HWPOISON test...TEST_PASSED >> ... HugeTLB seek then read HWPOISON test... >> ... ... init val=4 with offset=0x102000 >> ... ... expect to read 0xfe000 bytes of data in total >> ... ... actually read 0xfe000 bytes of data in total >> ... HugeTLB seek then read HWPOISON test...TEST_PASSED >> ... >> >> [ 2109.209225] Injecting memory failure for pfn 0x3190d01 at process >> virtual address 0x7f75e3101000 >> [ 2109.209438] Memory failure: 0x3190d01: recovery action for huge >> page: Recovered >> ... >> >> I think something in between broken MADV_HWPOISON on hugetlbfs, and we >> should be able to figure it out via bisection (and of course by >> reading delta commits between them, probably related to page >> refcount). > Thank you for this information. > >> >> That being said, I will be on vacation from tomorrow until the end of >> next week. So I will get back to this after next weekend. Meanwhile if >> you want to go ahead and bisect the problematic commit, that will be >> very much appreciated. > I'll try to bisect and post here if I find something. Found the culprit commit by bisection: a08c7193e4f18dc8508f2d07d0de2c5b94cb39a3 mm/filemap: remove hugetlb special casing in filemap.c hugetlb-read-hwpoison started failing from this patch. I've added the author of this patch to this bug report. > >> >> Thanks, >> Jiaqi >> >> >>> >>> Regards, >>> Usama >>>