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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4337DC433EF for ; Mon, 27 Jun 2022 03:32:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232194AbiF0Dc1 (ORCPT ); Sun, 26 Jun 2022 23:32:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60008 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232135AbiF0DcX (ORCPT ); Sun, 26 Jun 2022 23:32:23 -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 E02682DFE for ; Sun, 26 Jun 2022 20:32:21 -0700 (PDT) Received: from localhost (unknown [117.48.120.186]) by mail-m2835.qiye.163.com (Hmail) with ESMTPA id 4082A8A010E; Mon, 27 Jun 2022 11:32:19 +0800 (CST) Date: Mon, 27 Jun 2022 11:32:15 +0800 From: Tao Liu To: yaminf@nvidia.com, leonro@nvidia.com Cc: linux-rdma@vger.kernel.org, saeedm@nvidia.com, talgi@nvidia.com, mgurtovoy@nvidia.com, jgg@nvidia.com Subject: Re: [PATCH RFC net] linux/dim: Fix divide 0 in RDMA DIM. Message-ID: References: <20220623085858.42945-1-thomas.liu@ucloud.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220623085858.42945-1-thomas.liu@ucloud.cn> X-HM-Spam-Status: e1kfGhgUHx5ZQUtXWQgPGg8OCBgUHx5ZQUlOS1dZFg8aDwILHllBWSg2Ly tZV1koWUFJQjdXWS1ZQUlXWQ8JGhUIEh9ZQVkaH0gZVksfGk1KSk8eTUlJT1UZERMWGhIXJBQOD1 lXWRgSC1lBWUpKTFVPQ1VKSUtVSkNNWVdZFhoPEhUdFFlBWU9LSFVKSktISkxVS1kG X-HM-Sender-Digest: e1kMHhlZQR0aFwgeV1kSHx4VD1lBWUc6KzY6FQw4VjIIAwk8EgMYNQ0K IRlPCy1VSlVKTU5NSEtLTEhCTUhIVTMWGhIXVQ8TFBYaCFUXEg47DhgXFA4fVRgVRVlXWRILWUFZ SkpMVU9DVUpJS1VKQ01ZV1kIAVlBT0xKSjcG X-HM-Tid: 0a81a3379ac9841dkuqw4082a8a010e Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org Hi, Yamin and Leon. Do you have any comments about this patch? On Thu, Jun 23, 2022 at 04:58:58PM +0800, Tao Liu wrote: > We hit a divide 0 error in ofed 5.1.2.3.7.1. But dim.c and > rdma_dim.c seem same as upstream. > > 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 > > crash> struct dim ffff88096cd7f780 > struct dim { > state = 1 '\001', > prev_stats = { > ppms = 2142150514, > bpms = 391112768, > epms = -30709, > cpms = 1, > cpe_ratio = 0 > }, > start_sample = { > time = 51174507127193614, > pkt_ctr = 0, > byte_ctr = 0, > event_ctr = 1, > comp_ctr = 494693321 > }, > measuring_sample = { > time = 51174507266581985, > pkt_ctr = 0, > byte_ctr = 0, > event_ctr = 65, > comp_ctr = 494693385 > }, > work = { > data = { > counter = 128 > }, > entry = { > next = 0xffff88096cd7f7d0, > prev = 0xffff88096cd7f7d0 > }, > func = 0xffffffffa02b9f80 > }, > priv = 0xffff880b174fe800, > profile_ix = 1 '\001', > mode = 0 '\000', > tune_state = 2 '\002', > steps_right = 1 '\001', > steps_left = 1 '\001', > tired = 0 '\000' > } > > Fixes: f4915455dcf0 ("linux/dim: Implement RDMA adaptive moderation (DIM)") > Signed-off-by: Tao Liu > --- > lib/dim/rdma_dim.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/lib/dim/rdma_dim.c b/lib/dim/rdma_dim.c > index 15462d54758d..a657b106343c 100644 > --- a/lib/dim/rdma_dim.c > +++ b/lib/dim/rdma_dim.c > @@ -34,6 +34,9 @@ static int rdma_dim_stats_compare(struct dim_stats *curr, > return (curr->cpms > prev->cpms) ? DIM_STATS_BETTER : > DIM_STATS_WORSE; > > + if (!prev->cpe_ratio) > + return DIM_STATS_SAME; > + > if (IS_SIGNIFICANT_DIFF(curr->cpe_ratio, prev->cpe_ratio)) > return (curr->cpe_ratio > prev->cpe_ratio) ? DIM_STATS_BETTER : > DIM_STATS_WORSE; > -- > 2.30.1 (Apple Git-130) > >