From owner-dev-commits-src-main@freebsd.org Thu May 13 19:18:30 2021 Return-Path: Delivered-To: dev-commits-src-main@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 7E7AE62C501; Thu, 13 May 2021 19:18:30 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4Fh1fG382Jz3nlx; Thu, 13 May 2021 19:18:30 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 5ED3224273; Thu, 13 May 2021 19:18:30 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 14DJIUcn030196; Thu, 13 May 2021 19:18:30 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 14DJIU4i030195; Thu, 13 May 2021 19:18:30 GMT (envelope-from git) Date: Thu, 13 May 2021 19:18:30 GMT Message-Id: <202105131918.14DJIU4i030195@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Lutz Donnerhacke Subject: git: 4dfe70fdbda0 - main - netgraph/ng_bridge: Avoid cache thrashing MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: donner X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 4dfe70fdbda05453e824bc9edfc0d09eab7b2929 Auto-Submitted: auto-generated X-BeenThere: dev-commits-src-main@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commit messages for the main branch of the src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 13 May 2021 19:18:30 -0000 The branch main has been updated by donner: URL: https://cgit.FreeBSD.org/src/commit/?id=4dfe70fdbda05453e824bc9edfc0d09eab7b2929 commit 4dfe70fdbda05453e824bc9edfc0d09eab7b2929 Author: Lutz Donnerhacke AuthorDate: 2021-02-11 22:59:11 +0000 Commit: Lutz Donnerhacke CommitDate: 2021-05-13 19:14:36 +0000 netgraph/ng_bridge: Avoid cache thrashing Hint the compiler, that this update is needed at most once per second. Only in this case the memory line needs to be written. This will reduce the amount of cache trashing during forward of most frames. Suggested by: zec Approved by: zec MFC after: 2 weeks Differential Revision: https://reviews.freebsd.org/D28601 --- sys/netgraph/ng_bridge.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/sys/netgraph/ng_bridge.c b/sys/netgraph/ng_bridge.c index 470c0f05f18d..820c93515490 100644 --- a/sys/netgraph/ng_bridge.c +++ b/sys/netgraph/ng_bridge.c @@ -788,7 +788,8 @@ ng_bridge_rcvdata(hook_p hook, item_p item) * This is safe without locking, because it's * the only operation during shared access. */ - host->staleness = 0; + if (__predict_false(host->staleness > 0)) + host->staleness = 0; if ((host == NULL && ctx.incoming->learnMac) || (host != NULL && host->link != ctx.incoming)) {