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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 43A9FE64A8F for ; Tue, 3 Dec 2024 13:25:44 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A968A6B007B; Tue, 3 Dec 2024 08:25:43 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A1FFB6B0083; Tue, 3 Dec 2024 08:25:43 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 898B56B0085; Tue, 3 Dec 2024 08:25:43 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 6A52E6B007B for ; Tue, 3 Dec 2024 08:25:43 -0500 (EST) Received: from smtpin09.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 10A8512093B for ; Tue, 3 Dec 2024 13:25:43 +0000 (UTC) X-FDA: 82853719368.09.096B427 Received: from mail-lf1-f49.google.com (mail-lf1-f49.google.com [209.85.167.49]) by imf07.hostedemail.com (Postfix) with ESMTP id 7DE0940015 for ; Tue, 3 Dec 2024 13:25:27 +0000 (UTC) Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=Wr+TCL7z; spf=pass (imf07.hostedemail.com: domain of urezki@gmail.com designates 209.85.167.49 as permitted sender) smtp.mailfrom=urezki@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1733232332; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=zVR4tTaetOCSp6LEcvJ9nHP83elc5RNEVZ95fPAkdrQ=; b=fFrR5EPC+226xdtkyoMG3w2If78l+B5s6LsED4F+GSuHNYezWUAcj7jOPDhg5fc5gFfyDG bRpDTkCKWtDg6uOlA07aedAys9D5JdjysXzb0n/I2IdIhvnDqsOZXs/sQZlugjwllesXsa YV6YtXiABlyuCB66/owjWK/O5AQ9iRk= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=Wr+TCL7z; spf=pass (imf07.hostedemail.com: domain of urezki@gmail.com designates 209.85.167.49 as permitted sender) smtp.mailfrom=urezki@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1733232332; a=rsa-sha256; cv=none; b=BVzdupPNIZGiz7Z5ysZl5si+u3GO1DUdt57kesDXujVZNrQKDKU1KmFbc/sKNHsTbj/z9m wYSvjAAnfRGOU6RWqg2o19uEDMBOAgzW7U35KJDgoxyRNc46tyxvvteJz3Ac021JYboLg9 yjgVFCLodHDSRWDoQXMdhFoZbwM6zxY= Received: by mail-lf1-f49.google.com with SMTP id 2adb3069b0e04-53de852a287so6206473e87.2 for ; Tue, 03 Dec 2024 05:25:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1733232339; x=1733837139; darn=kvack.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:date:from:from:to:cc:subject:date:message-id:reply-to; bh=zVR4tTaetOCSp6LEcvJ9nHP83elc5RNEVZ95fPAkdrQ=; b=Wr+TCL7z80d10OGySHsbTldxj7p8OghoVCVwhrmi3i0Ree7y//0WyciIiq3xKAY0KV Qw2MTCW1RCKCY3eKWx/Z02cJ5j1+9kB0xDu9nVYYZh5h+o4e0YU6qzMCfzv2lje80kca /4ErLUvl1yx3w9jwlB6dB9qqut/mwPMORWis2pAWBTbY0qDa4dgzAWV0Sqq6vSvd7EQr fZYs+4bpQq0ASgk/cvHbYfiZSb9n9TP5KxgM/66ZozdpHc2vl8Y9iqm97w6li8CXRZyj XsrFpLy1Bqr6F15cmeRTg35VuQJoxMI4U9eqYh93ZV8X8XR4cGq7GCTcj9Ko8oukJSgJ qZGQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1733232339; x=1733837139; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:date:from:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=zVR4tTaetOCSp6LEcvJ9nHP83elc5RNEVZ95fPAkdrQ=; b=r4RiS8koSJu9wltkwafJQgOOgplvQdpAuXBZCGetdo2WyHdOIa5VcNYGedNfY1YrEv Nje41xPB0wUdlJDgj0JvjXNqGuQKdiYmv5Be6Qt0Ze7aqjA0lw63nSJy2B+tyHGnyY4G P6ciU8GFxe9vya992Fx3wZiogJ8UkzXq4nCusifVragHvXVCn47xtl/kMi8HdH1cD1b5 6DoIdjCL/EuimNnexYiH8Ekpsh0Icyvjhd3lX0Ynusrp6jXWlwj5/GmhspHZtGF9z9Dj fty7q2geCT7e+UgmWLCofceqZfRAa1qTl9dQ0gn5sbT7K0xDqAPSJCiHMVRjFWQ0dp79 FIkw== X-Forwarded-Encrypted: i=1; AJvYcCUG3o+CERt4h/uaRHdFyT8on9eCwOmtD+xc6op0okxIpWpYqhsxp7n0Yfb1ZaOE7wLMpKOhg87/Yg==@kvack.org X-Gm-Message-State: AOJu0YweYBbamOlUPbaQE7CTv7h9t+FXDjCE0bEpbBYzr8eZkHLwkWbm JqWLsEHLnugfO9KkZM5c8LpddmEgiKZhZG8onCv/wUMuN1LNdVNt X-Gm-Gg: ASbGnctZL9xzzi9Nhx9zfbHSkKjNc1TQ9OMAukRD1R8XS706mB5He5G8vnMRktp/8dB 0hYPYCaFfv1MyHjZq2yHc6uLUC1fJE3V7MspqZUYgkE7BXSIaQuhjuLWvuzR4TatA5CIkM8mry5 6my8VXS1goIjIvU8CBYrltiCiVxsm/YOSI9slclcC9NxJ7xV0z4jSO8cX3mUC6uDtYOhCC8GR1R Tjg9lCuF95vStVYyG4bk/70BvnC7icHuMH3+Jv3ye8Hbt0rPU6oVDipfXY9HIjGnHO+C4aLP90= X-Google-Smtp-Source: AGHT+IE7x1g7HJ509iRHUMOOdJCVlOyYF8QX+s7i7tJU2rZxM20grZvFX8lpvALpliHISfEMvLG12w== X-Received: by 2002:a05:6512:2209:b0:53d:a264:f25a with SMTP id 2adb3069b0e04-53e1b8c11e5mr96105e87.47.1733232338790; Tue, 03 Dec 2024 05:25:38 -0800 (PST) Received: from pc636 (host-95-203-13-87.mobileonline.telia.com. [95.203.13.87]) by smtp.gmail.com with ESMTPSA id 2adb3069b0e04-53df6443305sm1849828e87.79.2024.12.03.05.25.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 03 Dec 2024 05:25:38 -0800 (PST) From: Uladzislau Rezki X-Google-Original-From: Uladzislau Rezki Date: Tue, 3 Dec 2024 14:25:35 +0100 To: zuoze Cc: Uladzislau Rezki , Matthew Wilcox , gustavoars@kernel.org, akpm@linux-foundation.org, linux-hardening@vger.kernel.org, linux-mm@kvack.org, keescook@chromium.org, wangkefeng.wang@huawei.com Subject: Re: [PATCH -next] mm: usercopy: add a debugfs interface to bypass the vmalloc check. Message-ID: References: <20241203023159.219355-1-zuoze1@huawei.com> <57f9eca2-effc-3a9f-932b-fd37ae6d0f87@huawei.com> <92768fc4-4fe0-f74a-d61c-dde0eb64e2c0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <92768fc4-4fe0-f74a-d61c-dde0eb64e2c0@huawei.com> X-Rspamd-Server: rspam05 X-Stat-Signature: ynnzzbwds8w4tysabagj6n9henr4mmp9 X-Rspamd-Queue-Id: 7DE0940015 X-Rspam-User: X-HE-Tag: 1733232327-220846 X-HE-Meta: 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 iDwicNFd QupET8Ar9YZIn7V3TBXb91YKgCSSWXblMRJT32yZBw6szOwDUGY51z0bTFyOuVMHmSjzeXz8qWwQ2Q+CAJyM8IFbxlB/wFHX1Usf6PTIOYxjamvMIrz2XlkriBA7rT3WMAa1v2XpmDs9cbB9mmDR4ovT8eI4zwESReARK1x1GCSowmNgNWMK9oIjouO6HFo8Dm65cYixZ49oLuBTwJCszcNJSnmnfEnVc5K5ZRAMi4eXm9zVJ/R1iMSn88kk3pAWNN+sgUxwG9UhmmtMLCfYfCV511pAwN/FuRAcLUkAZC5u/KYnNFxR864m6bk6lHvi52nzfNvkEGS8dVmcZwnjGExJA+I295xvYiFWNSONb4BnYnjOQAi1Ah2jE6s+a61jq+CUJe8LJ8cuSpX2RCKkx1P39vAU7kqBk0xCRSPo148DRh8xpXmGfDYmQWW+cbeSxzRaqeISTlir7B7gW1pX9nJ7Y7USQMS2f2jfL X-Bogosity: Ham, tests=bogofilter, spamicity=0.011792, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: > > On Tue, Dec 03, 2024 at 07:23:44PM +0800, zuoze wrote: > > > We have implemented host-guest communication based on the TUN device > > > using XSK[1]. The hardware is a Kunpeng 920 machine (ARM architecture), > > > and the operating system is based on the 6.6 LTS version with kernel > > > version 6.6. The specific stack for hotspot collection is as follows: > > > > > > - 100.00% 0.00% vhost-12384 [unknown] [k] 0000000000000000 > > > - ret_from_fork > > > - 99.99% vhost_task_fn > > > - 99.98% 0xffffdc59f619876c > > > - 98.99% handle_rx_kick > > > - 98.94% handle_rx > > > - 94.92% tun_recvmsg > > > - 94.76% tun_do_read > > > - 94.62% tun_put_user_xdp_zc > > > - 63.53% __check_object_size > > > - 63.49% __check_object_size.part.0 > > > find_vmap_area > > > - 30.02% _copy_to_iter > > > __arch_copy_to_user > > > - 2.27% get_rx_bufs > > > - 2.12% vhost_get_vq_desc > > > 1.49% __arch_copy_from_user > > > - 0.89% peek_head_len > > > 0.54% xsk_tx_peek_desc > > > - 0.68% vhost_add_used_and_signal_n > > > - 0.53% eventfd_signal > > > eventfd_signal_mask > > > - 0.94% handle_tx_kick > > > - 0.94% handle_tx > > > - handle_tx_copy > > > - 0.59% vhost_tx_batch.constprop.0 > > > 0.52% tun_sendmsg > > > > > > It can be observed that most of the overhead is concentrated in the > > > find_vmap_area function. > > > > > I see. Yes, it is pretty contented, since you run the v6.6 kernel. There > > was a work that tends to improve it to mitigate a vmap lock contention. > > See it here: https://lwn.net/Articles/956590/ > > > > The work was taken in the v6.9 kernel: > > > > > > commit 38f6b9af04c4b79f81b3c2a0f76d1de94b78d7bc > > Author: Uladzislau Rezki (Sony) > > Date: Tue Jan 2 19:46:23 2024 +0100 > > > > mm: vmalloc: add va_alloc() helper > > > > Patch series "Mitigate a vmap lock contention", v3. > > > > 1. Motivation > > ... > > > > > > Could you please try the v6.9 kernel on your setup? > > > > How to solve it, probably, it can be back-ported to the v6.6 kernel. > > All the vmalloc-related optimizations have already been merged into 6.6, > including the set of optimization patches you suggested. Thank you very > much for your input. > Do you mean that the perf-data that you posted to this email thread, contains the: Patch series "Mitigate a vmap lock contention", v3. from the v6.9? and you still see a high contention? Thank you! -- Uladzislau Rezki