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 6D4FDC433F5 for ; Sat, 21 May 2022 01:21:12 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 99DA96B0071; Fri, 20 May 2022 21:21:11 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 925DA6B0072; Fri, 20 May 2022 21:21:11 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 79FB86B0073; Fri, 20 May 2022 21:21:11 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 638FE6B0071 for ; Fri, 20 May 2022 21:21:11 -0400 (EDT) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 123D52068A for ; Sat, 21 May 2022 01:21:11 +0000 (UTC) X-FDA: 79487996742.19.186818E Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf08.hostedemail.com (Postfix) with ESMTP id 89BE7160017 for ; Sat, 21 May 2022 01:20:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=aLneGAaicP7hJgLs7K/60mukpOwB1SE1HTp33RQdMZQ=; b=YNnS5d8zRhoTzc1eQrHEqej/2F uVR0V63Dhw61OSkUKQFZRgkIAJ0a4ikH2bZnBElWAoFR7xsCp5b6b2EVkpTmhqahUiigxiEJCU8W8 ygeuv8STRXY8QgwPHvdwu/eLe5mHIJPWjUGiLID/KuQVBeEHOWfKMPs/M5n0zDPguIi7/iR/evOfd GRl1XxGTr+een5l5ie/9FWjkLVH3Q8PWIEYbCxUzXL2cIzHe2SoOHlkorxnuxLG83Dw8UmFNdN+gp lWQJlJcW7r9+sRWL2/FygwFkb8rxZU+9wXfvSQlMboTeawcnLq16mBJmdK5D/EwDcaW6ofHQ3RSxb mf2dyGLg==; Received: from mcgrof by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1nsDnb-00F7xk-M2; Sat, 21 May 2022 01:20:55 +0000 Date: Fri, 20 May 2022 18:20:55 -0700 From: Luis Chamberlain To: Song Liu , Rick Edgecombe , Arnd Bergmann , Davidlohr Bueso , Borislav Petkov Cc: linux-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-mm@kvack.org, ast@kernel.org, daniel@iogearbox.net, peterz@infradead.org, torvalds@linux-foundation.org, kernel-team@fb.com Subject: Re: [PATCH v3 bpf-next 5/8] bpf: use module_alloc_huge for bpf_prog_pack Message-ID: References: <20220520031548.338934-1-song@kernel.org> <20220520031548.338934-6-song@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 89BE7160017 X-Stat-Signature: m1noztkh7rmskzrhfba17sgm7rema4om Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=YNnS5d8z; spf=none (imf08.hostedemail.com: domain of mcgrof@infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=mcgrof@infradead.org; dmarc=fail reason="No valid SPF, DKIM not aligned (relaxed)" header.from=kernel.org (policy=none) X-Rspam-User: X-HE-Tag: 1653096051-260507 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, May 20, 2022 at 06:00:57PM -0700, Luis Chamberlain wrote: > On Thu, May 19, 2022 at 08:15:45PM -0700, Song Liu wrote: > > Use module_alloc_huge for bpf_prog_pack so that BPF programs sit on > > PMD_SIZE pages. This benefits system performance by reducing iTLB miss > > rate. Benchmark of a real web service workload shows this change gives > > another ~0.2% performance boost on top of PAGE_SIZE bpf_prog_pack > > (which improve system throughput by ~0.5%). Also, seems like a is a missed opportunity to show iTLB misses with more detail. If there was a selftest to stress bpf JIT you could use perf and enable anyone to quanitfy gains. Dave hinted with some ideas with perf: perf stat -e cpu/event=0x8,umask=0x84,name=dtlb_load_misses_walk_duration/,cpu/event=0x8,umask=0x82,name=dtlb_load_misses_walk_completed/,cpu/event=0x49,umask=0x4,name=dtlb_store_misses_walk_duration/,cpu/event=0x49,umask=0x2,name=dtlb_store_misses_walk_completed/,cpu/event=0x85,umask=0x4,name=itlb_misses_walk_duration/,cpu/event=0x85,umask=0x2,name=itlb_misses_walk_completed/ some_bpf_jit_test Luis