From owner-dev-commits-src-all@freebsd.org Tue Jul 20 23:46:23 2021 Return-Path: Delivered-To: dev-commits-src-all@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 2763A655365; Tue, 20 Jul 2021 23:46:23 +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 4GTwMy6dTYz3PMn; Tue, 20 Jul 2021 23:46:22 +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 C368C13ED8; Tue, 20 Jul 2021 23:46:22 +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 16KNkMZK054607; Tue, 20 Jul 2021 23:46:22 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 16KNkMAG054606; Tue, 20 Jul 2021 23:46:22 GMT (envelope-from git) Date: Tue, 20 Jul 2021 23:46:22 GMT Message-Id: <202107202346.16KNkMAG054606@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Vladimir Kondratyev Subject: git: ddebb8c0f780 - stable/13 - LinuxKPI: Add compiler barriers to list_for_each_entry_lockless macro MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: wulf X-Git-Repository: src X-Git-Refname: refs/heads/stable/13 X-Git-Reftype: branch X-Git-Commit: ddebb8c0f780626d1dbd24725bbf9bc16bf4b819 Auto-Submitted: auto-generated X-BeenThere: dev-commits-src-all@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commit messages for all branches of the src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 20 Jul 2021 23:46:23 -0000 The branch stable/13 has been updated by wulf: URL: https://cgit.FreeBSD.org/src/commit/?id=ddebb8c0f780626d1dbd24725bbf9bc16bf4b819 commit ddebb8c0f780626d1dbd24725bbf9bc16bf4b819 Author: Vladimir Kondratyev AuthorDate: 2021-07-05 00:19:35 +0000 Commit: Vladimir Kondratyev CommitDate: 2021-07-20 22:43:52 +0000 LinuxKPI: Add compiler barriers to list_for_each_entry_lockless macro so this list-traversal primitive may safely run concurrently with the _rcu list-mutation primitives such as list_add_rcu() as long as the traversal is guarded by rcu_read_lock(). Do it by reusing the "list_for_each_entry_rcu" macro which does the same. On Linux it implements some additional lockdep stuff which we skip. Also move the macro to linux/rculist.h where it resides on Linux. Reviewed by: hselasky Differential revision: https://reviews.freebsd.org/D30795 (cherry picked from commit c0862b2b1fa91636d308a1a41d8dc370691d656e) --- sys/compat/linuxkpi/common/include/linux/list.h | 2 -- sys/compat/linuxkpi/common/include/linux/rculist.h | 3 +++ 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/sys/compat/linuxkpi/common/include/linux/list.h b/sys/compat/linuxkpi/common/include/linux/list.h index 93db449a4473..37b5b751d21b 100644 --- a/sys/compat/linuxkpi/common/include/linux/list.h +++ b/sys/compat/linuxkpi/common/include/linux/list.h @@ -202,8 +202,6 @@ list_del_init(struct list_head *entry) for (p = list_entry((h)->next, typeof(*p), field); &(p)->field != (h); \ p = list_entry((p)->field.next, typeof(*p), field)) -#define list_for_each_entry_lockless(...) list_for_each_entry(__VA_ARGS__) - #define list_for_each_entry_safe(p, n, h, field) \ for (p = list_entry((h)->next, typeof(*p), field), \ n = list_entry((p)->field.next, typeof(*p), field); &(p)->field != (h);\ diff --git a/sys/compat/linuxkpi/common/include/linux/rculist.h b/sys/compat/linuxkpi/common/include/linux/rculist.h index bff2f7e13184..6c21a6943f98 100644 --- a/sys/compat/linuxkpi/common/include/linux/rculist.h +++ b/sys/compat/linuxkpi/common/include/linux/rculist.h @@ -44,6 +44,9 @@ &(pos)->member != (head); \ pos = list_entry_rcu((pos)->member.next, typeof(*(pos)), member)) +#define list_for_each_entry_lockless(pos, head, member) \ + list_for_each_entry_rcu(pos, head, member) + static inline void linux_list_add_rcu(struct list_head *new, struct list_head *prev, struct list_head *next)