From patchwork Mon Jun 27 14:00:04 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tao Liu X-Patchwork-Id: 12896687 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4E3E8CCA473 for ; Mon, 27 Jun 2022 14:01:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234719AbiF0OBE (ORCPT ); Mon, 27 Jun 2022 10:01:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37204 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234788AbiF0OBA (ORCPT ); Mon, 27 Jun 2022 10:01:00 -0400 Received: from mail-m2835.qiye.163.com (mail-m2835.qiye.163.com [103.74.28.35]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 87EC7D11C for ; Mon, 27 Jun 2022 07:00:58 -0700 (PDT) Received: from localhost.localdomain (unknown [124.126.138.30]) by mail-m2835.qiye.163.com (Hmail) with ESMTPA id 5FE3A8A003E; Mon, 27 Jun 2022 22:00:56 +0800 (CST) From: Tao Liu To: linux-rdma@vger.kernel.org Cc: saeedm@nvidia.com, talgi@nvidia.com, leonro@nvidia.com, mgurtovoy@nvidia.com, jgg@nvidia.com, yaminf@nvidia.com, thomas.liu@ucloud.cn Subject: [PATCH v3] linux/dim: Fix divide 0 in RDMA DIM. Date: Mon, 27 Jun 2022 22:00:04 +0800 Message-Id: <20220627140004.3099-1-thomas.liu@ucloud.cn> X-Mailer: git-send-email 2.30.1 (Apple Git-130) MIME-Version: 1.0 X-HM-Spam-Status: e1kfGhgUHx5ZQUtXWQgPGg8OCBgUHx5ZQUlOS1dZFg8aDwILHllBWSg2Ly tZV1koWUFJQjdXWS1ZQUlXWQ8JGhUIEh9ZQVkaHkJKVk4aGhpLQh9CT0wZSVUZERMWGhIXJBQOD1 lXWRgSC1lBWUpJT1VKSU1VSkhDVUhLWVdZFhoPEhUdFFlBWU9LSFVKSktISkNVS1kG X-HM-Sender-Digest: e1kMHhlZQR0aFwgeV1kSHx4VD1lBWUc6OlE6HBw6EjIWSAgUAhI5OjlM EQ8aCSlVSlVKTU5NSEhDT05NTEJCVTMWGhIXVQ8TFBYaCFUXEg47DhgXFA4fVRgVRVlXWRILWUFZ SklPVUpJTVVKSENVSEtZV1kIAVlBSEhKTzcG X-HM-Tid: 0a81a5771f8f841dkuqw5fe3a8a003e Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org Fix a divide 0 error in rdma_dim_stats_compare() when prev->cpe_ratio == 0. CallTrace: Hardware name: H3C R4900 G3/RS33M2C9S, BIOS 2.00.37P21 03/12/2020 task: ffff880194b78000 task.stack: ffffc90006714000 RIP: 0010:backport_rdma_dim+0x10e/0x240 [mlx_compat] RSP: 0018:ffff880c10e83ec0 EFLAGS: 00010202 RAX: 0000000000002710 RBX: ffff88096cd7f780 RCX: 0000000000000064 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000001 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 000000001d7c6c09 R13: ffff88096cd7f780 R14: ffff880b174fe800 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff880c10e80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000a0965b00 CR3: 000000000200a003 CR4: 00000000007606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: ib_poll_handler+0x43/0x80 [ib_core] irq_poll_softirq+0xae/0x110 __do_softirq+0xd1/0x28c irq_exit+0xde/0xf0 do_IRQ+0x54/0xe0 common_interrupt+0x8f/0x8f ? cpuidle_enter_state+0xd9/0x2a0 ? cpuidle_enter_state+0xc7/0x2a0 ? do_idle+0x170/0x1d0 ? cpu_startup_entry+0x6f/0x80 ? start_secondary+0x1b9/0x210 ? secondary_startup_64+0xa5/0xb0 Code: 0f 87 e1 00 00 00 8b 4c 24 14 44 8b 43 14 89 c8 4d 63 c8 44 29 c0 99 31 d0 29 d0 31 d2 48 98 48 8d 04 80 48 8d 04 80 48 c1 e0 02 <49> f7 f1 48 83 f8 0a 0f 86 c1 00 00 00 44 39 c1 7f 10 48 89 df RIP: backport_rdma_dim+0x10e/0x240 [mlx_compat] RSP: ffff880c10e83ec0 Fixes: f4915455dcf0 ("linux/dim: Implement RDMA adaptive moderation (DIM)") Signed-off-by: Tao Liu Reviewed-by: Max Gurtovoy Acked-by: Leon Romanovsky --- include/linux/dim.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/dim.h b/include/linux/dim.h index b698266d0035..6c5733981563 100644 --- a/include/linux/dim.h +++ b/include/linux/dim.h @@ -21,7 +21,7 @@ * We consider 10% difference as significant. */ #define IS_SIGNIFICANT_DIFF(val, ref) \ - (((100UL * abs((val) - (ref))) / (ref)) > 10) + ((ref) && (((100UL * abs((val) - (ref))) / (ref)) > 10)) /* * Calculate the gap between two values.