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 CC7571F03D2 for ; Sat, 4 Apr 2026 11:43:04 +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=1775302984; cv=none; b=WKz0+uYRNQAM1em9y6gMS9QjazGxmKOp7/NUfCsdKReYlq3tMlSXybXFEnR/gKCTy1PfCKoxea3nWFAm1s1MvYy1Go0WDlWbes9bw5vtKDZo78oYvz7YLxQdSCdHHIr7plxIciM7BaJ3hzgpvAyISdXXggoo67n6qKxJliFPD9c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775302984; c=relaxed/simple; bh=Sdc6lsfMAqvIc1+DV7eIbKLZnEMQoI+ANeTpAGO2MHc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=aFPbBwQb5o+9F5XMHr0Bcjgqgkh/xw/KDPYkHgenQ4ZTtp0j0hcj6QIReLAH8C+BjI/2k7xqvNKBlj/HowAFCPdSGnQ7uH9kBFUydoVLyLza7zJcJIt5OVwwsyyx4ynyZ0jjfYcTj9tz5JmvSpHN+z5s0WG1A02UZn00xJWnEDQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=PumOeD9P; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="PumOeD9P" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2E12DC19421; Sat, 4 Apr 2026 11:43:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775302984; bh=Sdc6lsfMAqvIc1+DV7eIbKLZnEMQoI+ANeTpAGO2MHc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=PumOeD9PrfCj3v4zr0BX/wNZxuf5RFB5qfez52edp4luwHU/CiRNfD3UTaOChEcmX EkdROTqLeZ75OODQ8ldK3PXDxbTgKGsIdf9tN8jTpl/1Q9zHaPtszrOSMH5E9A3CdY GW2/4P/IpwL+KLBfwPsOI5iQZ1wq6s69WIA180Y0KgPXaU9s/eJCHeFJ3MCO0qdjPX aqWvp5ONiewd8C84VKXfPRPp7vr27f8Ddy1GWWPwPXth5sZhFBNhRyNlKFrAtNs4yt 6dbH+tSr1WiEHRdDeQflJUFqDWmDp4rtT8sbWQ+qK+jUPjxNg27Q96wZFbxB4idp5n gtovYJI9O7XWg== Date: Sat, 4 Apr 2026 22:42:59 +1100 From: Dave Chinner To: Matthew Wilcox Cc: linux-xfs@vger.kernel.org Subject: Re: Hang with xfs/285 on 2026-03-02 kernel Message-ID: References: Precedence: bulk X-Mailing-List: linux-xfs@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: On Fri, Apr 03, 2026 at 04:35:46PM +0100, Matthew Wilcox wrote: > This is with commit 5619b098e2fb so after 7.0-rc6 > INFO: task fsstress:3762792 blocked on a semaphore likely last held by task fsstress:3762793 > task:fsstress state:D stack:0 pid:3762793 tgid:3762793 ppid:3762783 task_flags:0x440140 flags:0x00080800 > Call Trace: > > __schedule+0x560/0xfc0 > schedule+0x3e/0x140 > schedule_timeout+0x84/0x110 > ? __pfx_process_timeout+0x10/0x10 > io_schedule_timeout+0x5b/0x80 > xfs_buf_alloc+0x793/0x7d0 -ENOMEM. It'll be looping here: fallback: for (;;) { bp->b_addr = __vmalloc(size, gfp_mask); if (bp->b_addr) break; if (flags & XBF_READ_AHEAD) return -ENOMEM; XFS_STATS_INC(bp->b_mount, xb_page_retries); memalloc_retry_wait(gfp_mask); } If it is looping here long enough to trigger the hang check timer, then the MM subsystem is not making progress reclaiming memory. This is probably a 16kB allocation (it's an inode cluster buffer), and the allocation context is NOFAIL because it is within a transaction (this loop pre-dates __vmalloc() supporting __GFP_NOFAIL).... All the other tasks are backed up on the AGI buffer lock held ... > xfs_buf_get_map+0x651/0xbd0 > ? _raw_spin_unlock+0x26/0x50 > xfs_trans_get_buf_map+0x141/0x300 > xfs_ialloc_inode_init+0x130/0x2c0 > xfs_ialloc_ag_alloc+0x226/0x710 > xfs_dialloc+0x22d/0x980 ... here by the task blocked on memory allocation. This smells like a persistent ENOMEM/memory reclaim issue and XFS is just the messenger... -Dave. -- Dave Chinner dgc@kernel.org