From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 30E177E0E8 for ; Wed, 19 Jun 2024 09:34:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718789691; cv=none; b=VEsEQCZWDiAryao3wTMC0vOHBjVPQGzJjxwqczQOFIk9/876+Q3U/zALYdfF8elnoErFb3uDTvs9vyW8Vi4RTY6go+EeW0hS8QOQFaOb8Mahf7H/kmFbSQEmQBv4bpNacR6dEsbHFSWjNzKuF14ZI8QHwbysswJZGkHgq207hLw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718789691; c=relaxed/simple; bh=0m9/AQ+vOYG0js4ZkmCDNCOXqKsuLqEWMthKnodDXMg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=P99c89Mbj15EIYRhIJGRlIUHfX2cDdVg1ebqfzJjtUDx+4Y6AUlV+nUHMImNIpfLk3MjjB19BaP1paqhwvHBKUaSP0bHR4oR+OwfR74nl02eb9JR/68iy0JssCLR8OEEst9xwON6Oj+vTwj7aXOGQ5PuqW17p2diFAKFy+vkXSA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Woc1nrje; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Woc1nrje" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 93E06C2BBFC; Wed, 19 Jun 2024 09:34:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1718789691; bh=0m9/AQ+vOYG0js4ZkmCDNCOXqKsuLqEWMthKnodDXMg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Woc1nrjeZwy/MQ8F2uPusIbSODIYPGPpy6G++/7XBbZhi8WBJsHSBiOEzOkQABmJH HVrIqBvFnIlhMh28M3vEEGA+p+5SLHPwhVNdGbQzTEtHZ4YhKBA0moMY0zwQajoBvB U90RiEqaox6SRXtRaSMUrJf4KoQV8l6VPxC4cTzY= Date: Wed, 19 Jun 2024 11:34:37 +0200 From: Greg KH To: Miaohe Lin Cc: stable@vger.kernel.org, David Hildenbrand , Yang Shi , Oscar Salvador , Anshuman Khandual , Naoya Horiguchi , Xu Yu , Andrew Morton Subject: Re: [PATCH 5.15.y] mm/huge_memory: don't unpoison huge_zero_folio Message-ID: <2024061928-basis-abdomen-bab7@gregkh> References: <2024061300-ceremony-habitable-06c0@gregkh> <20240618032727.2389102-1-linmiaohe@huawei.com> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240618032727.2389102-1-linmiaohe@huawei.com> On Tue, Jun 18, 2024 at 11:27:27AM +0800, Miaohe Lin wrote: > When I did memory failure tests recently, below panic occurs: > > kernel BUG at include/linux/mm.h:1135! > invalid opcode: 0000 [#1] PREEMPT SMP NOPTI > CPU: 9 PID: 137 Comm: kswapd1 Not tainted 6.9.0-rc4-00491-gd5ce28f156fe-dirty #14 > RIP: 0010:shrink_huge_zero_page_scan+0x168/0x1a0 > RSP: 0018:ffff9933c6c57bd0 EFLAGS: 00000246 > RAX: 000000000000003e RBX: 0000000000000000 RCX: ffff88f61fc5c9c8 > RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff88f61fc5c9c0 > RBP: ffffcd7c446b0000 R08: ffffffff9a9405f0 R09: 0000000000005492 > R10: 00000000000030ea R11: ffffffff9a9405f0 R12: 0000000000000000 > R13: 0000000000000000 R14: 0000000000000000 R15: ffff88e703c4ac00 > FS: 0000000000000000(0000) GS:ffff88f61fc40000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 000055f4da6e9878 CR3: 0000000c71048000 CR4: 00000000000006f0 > Call Trace: > > do_shrink_slab+0x14f/0x6a0 > shrink_slab+0xca/0x8c0 > shrink_node+0x2d0/0x7d0 > balance_pgdat+0x33a/0x720 > kswapd+0x1f3/0x410 > kthread+0xd5/0x100 > ret_from_fork+0x2f/0x50 > ret_from_fork_asm+0x1a/0x30 > > Modules linked in: mce_inject hwpoison_inject > ---[ end trace 0000000000000000 ]--- > RIP: 0010:shrink_huge_zero_page_scan+0x168/0x1a0 > RSP: 0018:ffff9933c6c57bd0 EFLAGS: 00000246 > RAX: 000000000000003e RBX: 0000000000000000 RCX: ffff88f61fc5c9c8 > RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff88f61fc5c9c0 > RBP: ffffcd7c446b0000 R08: ffffffff9a9405f0 R09: 0000000000005492 > R10: 00000000000030ea R11: ffffffff9a9405f0 R12: 0000000000000000 > R13: 0000000000000000 R14: 0000000000000000 R15: ffff88e703c4ac00 > FS: 0000000000000000(0000) GS:ffff88f61fc40000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 000055f4da6e9878 CR3: 0000000c71048000 CR4: 00000000000006f0 > > The root cause is that HWPoison flag will be set for huge_zero_folio > without increasing the folio refcnt. But then unpoison_memory() will > decrease the folio refcnt unexpectedly as it appears like a successfully > hwpoisoned folio leading to VM_BUG_ON_PAGE(page_ref_count(page) == 0) when > releasing huge_zero_folio. > > Skip unpoisoning huge_zero_folio in unpoison_memory() to fix this issue. > We're not prepared to unpoison huge_zero_folio yet. > > Link: https://lkml.kernel.org/r/20240516122608.22610-1-linmiaohe@huawei.com > Fixes: 478d134e9506 ("mm/huge_memory: do not overkill when splitting huge_zero_page") > Signed-off-by: Miaohe Lin > Acked-by: David Hildenbrand > Reviewed-by: Yang Shi > Reviewed-by: Oscar Salvador > Reviewed-by: Anshuman Khandual > Cc: Naoya Horiguchi > Cc: Xu Yu > Cc: > Signed-off-by: Andrew Morton > (cherry picked from commit fe6f86f4b40855a130a19aa589f9ba7f650423f4) > Signed-off-by: Miaohe Lin > --- > mm/memory-failure.c | 7 +++++++ > 1 file changed, 7 insertions(+) > All now queued up, thanks! greg k-h