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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 61192C47DDB for ; Sun, 28 Jan 2024 16:13:53 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 7A5041126EB; Sun, 28 Jan 2024 16:13:52 +0000 (UTC) Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by gabe.freedesktop.org (Postfix) with ESMTPS id D82CC1126EA; Sun, 28 Jan 2024 16:13:50 +0000 (UTC) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 5F45661BAA; Sun, 28 Jan 2024 16:13:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 90087C433A6; Sun, 28 Jan 2024 16:13:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1706458430; bh=YQxG6SF6UMB/tSrGXxlg5ZxSf6zRK+U+SLh8s5R23xo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Xb3wBw4sd8kPC2uYCMUDur2nvDEIq6wUCPP6CkNXV2zE/ofycIObTVYkXeo4VFPig m41gRhzb3cbpkx+W5mjzT32Cer1eiczQ9N+WFBnlElMSgyHN+sLs0BsiwuhQDMf2mQ QdarlQixAoSBcjWGV2UXeSoNR6TWzLS8oWlzsGFK5tUiZ3BK9zBK6+ptwXyO0gThyh Wvg/KBV+mDUJGeub5Jq4uBHejbxFmj5euIHe3+4hVwgYRHclyDVZZFrdre8+WG9cDE P6xogfruAkRQwrPIEEjb4yxdpvd4+QXgPGmkIVQAGAnkNeFV5EGYCiizrQYbWUtUhA LFyc5gbTzHthQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH AUTOSEL 6.6 20/31] drm/amdkfd: Fix lock dependency warning with srcu Date: Sun, 28 Jan 2024 11:12:50 -0500 Message-ID: <20240128161315.201999-20-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240128161315.201999-1-sashal@kernel.org> References: <20240128161315.201999-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.6.14 Content-Transfer-Encoding: 8bit X-BeenThere: amd-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussion list for AMD gfx List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Sasha Levin , Philip Yang , Felix.Kuehling@amd.com, Xinhui.Pan@amd.com, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, daniel@ffwll.ch, Alex Deucher , airlied@gmail.com, christian.koenig@amd.com Errors-To: amd-gfx-bounces@lists.freedesktop.org Sender: "amd-gfx" From: Philip Yang [ Upstream commit 2a9de42e8d3c82c6990d226198602be44f43f340 ] ====================================================== WARNING: possible circular locking dependency detected 6.5.0-kfd-yangp #2289 Not tainted ------------------------------------------------------ kworker/0:2/996 is trying to acquire lock: (srcu){.+.+}-{0:0}, at: __synchronize_srcu+0x5/0x1a0 but task is already holding lock: ((work_completion)(&svms->deferred_list_work)){+.+.}-{0:0}, at: process_one_work+0x211/0x560 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 ((work_completion)(&svms->deferred_list_work)){+.+.}-{0:0}: __flush_work+0x88/0x4f0 svm_range_list_lock_and_flush_work+0x3d/0x110 [amdgpu] svm_range_set_attr+0xd6/0x14c0 [amdgpu] kfd_ioctl+0x1d1/0x630 [amdgpu] __x64_sys_ioctl+0x88/0xc0 -> #2 (&info->lock#2){+.+.}-{3:3}: __mutex_lock+0x99/0xc70 amdgpu_amdkfd_gpuvm_restore_process_bos+0x54/0x740 [amdgpu] restore_process_helper+0x22/0x80 [amdgpu] restore_process_worker+0x2d/0xa0 [amdgpu] process_one_work+0x29b/0x560 worker_thread+0x3d/0x3d0 -> #1 ((work_completion)(&(&process->restore_work)->work)){+.+.}-{0:0}: __flush_work+0x88/0x4f0 __cancel_work_timer+0x12c/0x1c0 kfd_process_notifier_release_internal+0x37/0x1f0 [amdgpu] __mmu_notifier_release+0xad/0x240 exit_mmap+0x6a/0x3a0 mmput+0x6a/0x120 do_exit+0x322/0xb90 do_group_exit+0x37/0xa0 __x64_sys_exit_group+0x18/0x20 do_syscall_64+0x38/0x80 -> #0 (srcu){.+.+}-{0:0}: __lock_acquire+0x1521/0x2510 lock_sync+0x5f/0x90 __synchronize_srcu+0x4f/0x1a0 __mmu_notifier_release+0x128/0x240 exit_mmap+0x6a/0x3a0 mmput+0x6a/0x120 svm_range_deferred_list_work+0x19f/0x350 [amdgpu] process_one_work+0x29b/0x560 worker_thread+0x3d/0x3d0 other info that might help us debug this: Chain exists of: srcu --> &info->lock#2 --> (work_completion)(&svms->deferred_list_work) Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((work_completion)(&svms->deferred_list_work)); lock(&info->lock#2); lock((work_completion)(&svms->deferred_list_work)); sync(srcu); Signed-off-by: Philip Yang Reviewed-by: Felix Kuehling Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c index a4c911fa1675..b51224a85a38 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c @@ -2343,8 +2343,10 @@ static void svm_range_deferred_list_work(struct work_struct *work) mutex_unlock(&svms->lock); mmap_write_unlock(mm); - /* Pairs with mmget in svm_range_add_list_work */ - mmput(mm); + /* Pairs with mmget in svm_range_add_list_work. If dropping the + * last mm refcount, schedule release work to avoid circular locking + */ + mmput_async(mm); spin_lock(&svms->deferred_list_lock); } -- 2.43.0