From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-182.mta1.migadu.com (out-182.mta1.migadu.com [95.215.58.182]) (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 31BBF23956A for ; Mon, 13 Oct 2025 09:15:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760346922; cv=none; b=DGCz+z4h6bm8M6VIrk/sQLbL3y3Xp2Wst9RfrUbvE3NX8j9oDTl/F+WqOIsDn4ZkvqvDlWC9C7w2y91BsgSm2bwm2THabzoW1CA2bNSxnxb4kY9uVHugxXSLmbIlD19BQq0bb7+Y0WbTt1LcQr42jSFbapjDQbWHyGZ5Oyg4uMc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760346922; c=relaxed/simple; bh=7U/uYJ1Bn25KT2yXUo5NMdtSLLLWGrEc4B4/9Q9wzXc=; h=Message-ID:Date:MIME-Version:Subject:From:To:Cc:References: In-Reply-To:Content-Type; b=VJwqRSjBwBA64QOZmtthITYlJvs3P29BBd9u2JkpD2niTWcwv99sHIzy+QscHcrGC4Q0PP360fCMeOk9WipsmPn0b3SOtPufkFv2V191GAX59CkX2ukAgZ6b5V3Wza0OTAc/fQ1sQPsNo4Ze0dlRH6xnLruivSmuBQJM0GQIoNo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=MNQbpMfF; arc=none smtp.client-ip=95.215.58.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="MNQbpMfF" Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1760346918; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=z3uRU6A1V0MHfLT+ewa3AKJSUpsO5lmxHPh4GX6k0hg=; b=MNQbpMfFLQ2qpDDSdEkaNskbe9MHMp0xnYzedG+FVz6nyRLbQztirK+kx5Ir54ngMxaThf WDc8Q/rKrID2o68szkR+UWaJ0QWxIRx9EQGrVza8abnWCj8lKlo3duhrKfY5vZdssNRneh dVALp7ix5m0wpB/l+OyGFcibB55Y9ls= Date: Mon, 13 Oct 2025 17:15:09 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH RFC 1/1] mm/ksm: Add recovery mechanism for memory failures Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Lance Yang To: david@redhat.com Cc: Longlong Xia , nao.horiguchi@gmail.com, akpm@linux-foundation.org, wangkefeng.wang@huawei.com, xu.xin16@zte.com.cn, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Longlong Xia , lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, vbabka@suse.cz, rppt@kernel.org, surenb@google.com, mhocko@suse.com, Miaohe Lin , qiuxu.zhuo@intel.com References: <20251009070045.2011920-1-xialonglong2025@163.com> <20251009070045.2011920-2-xialonglong2025@163.com> <55370eb6-9798-0f46-2301-d5f66528411b@huawei.com> <077882e3-f69f-44f3-aa74-b325721beb42@linux.dev> <839b72b8-55dc-4f4e-b1da-6f24ecf9446f@huawei.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT @David Cc: MM CORE folks On 2025/10/13 12:42, Lance Yang wrote: [...] Cool. Hardware error injection with EINJ was the way to go! I just ran some tests on the shared zero page (both regular and huge), and found a tricky behavior: 1) When a hardware error is injected into the zeropage, the process that attempts to read from a mapping backed by it is correctly killed with a SIGBUS. 2) However, even after the error is detected, the kernel continues to install the known-poisoned zeropage for new anonymous mappings ... For the shared zeropage: ``` [Mon Oct 13 16:29:02 2025] mce: Uncorrected hardware memory error in user-access at 29b8cf5000 [Mon Oct 13 16:29:02 2025] Memory failure: 0x29b8cf5: Sending SIGBUS to read_zeropage:13767 due to hardware memory corruption [Mon Oct 13 16:29:02 2025] Memory failure: 0x29b8cf5: recovery action for already poisoned page: Failed ``` And for the shared huge zeropage: ``` [Mon Oct 13 16:35:34 2025] mce: Uncorrected hardware memory error in user-access at 1e1e00000 [Mon Oct 13 16:35:34 2025] Memory failure: 0x1e1e00: Sending SIGBUS to read_huge_zerop:13891 due to hardware memory corruption [Mon Oct 13 16:35:34 2025] Memory failure: 0x1e1e00: recovery action for already poisoned page: Failed ``` Since we've identified an uncorrectable hardware error on such a critical, singleton page, should we be doing something more? Thanks, Lance