From owner-svn-src-head@freebsd.org Fri Jan 31 08:36:50 2020 Return-Path: Delivered-To: svn-src-head@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 20DB82385E3; Fri, 31 Jan 2020 08:36:50 +0000 (UTC) (envelope-from mjg@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) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4889Yt06jTz4HWb; Fri, 31 Jan 2020 08:36:50 +0000 (UTC) (envelope-from mjg@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id F346CB2E1; Fri, 31 Jan 2020 08:36:49 +0000 (UTC) (envelope-from mjg@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id 00V8anWL057690; Fri, 31 Jan 2020 08:36:49 GMT (envelope-from mjg@FreeBSD.org) Received: (from mjg@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id 00V8anjE057688; Fri, 31 Jan 2020 08:36:49 GMT (envelope-from mjg@FreeBSD.org) Message-Id: <202001310836.00V8anjE057688@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: mjg set sender to mjg@FreeBSD.org using -f From: Mateusz Guzik Date: Fri, 31 Jan 2020 08:36:49 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r357320 - in head/sys: kern sys X-SVN-Group: head X-SVN-Commit-Author: mjg X-SVN-Commit-Paths: in head/sys: kern sys X-SVN-Commit-Revision: 357320 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 31 Jan 2020 08:36:50 -0000 Author: mjg Date: Fri Jan 31 08:36:49 2020 New Revision: 357320 URL: https://svnweb.freebsd.org/changeset/base/357320 Log: Add rms_try_rlock and rms_wowned. Modified: head/sys/kern/kern_rmlock.c head/sys/sys/rmlock.h Modified: head/sys/kern/kern_rmlock.c ============================================================================== --- head/sys/kern/kern_rmlock.c Fri Jan 31 08:36:23 2020 (r357319) +++ head/sys/kern/kern_rmlock.c Fri Jan 31 08:36:49 2020 (r357320) @@ -934,6 +934,30 @@ rms_rlock(struct rmslock *rms) critical_exit(); } +int +rms_try_rlock(struct rmslock *rms) +{ + int *influx; + + critical_enter(); + influx = zpcpu_get(rms->readers_influx); + __compiler_membar(); + *influx = 1; + __compiler_membar(); + if (__predict_false(rms->writers > 0)) { + __compiler_membar(); + *influx = 0; + critical_exit(); + return (0); + } + __compiler_membar(); + (*zpcpu_get(rms->readers_pcpu))++; + __compiler_membar(); + *influx = 0; + critical_exit(); + return (1); +} + static void __noinline rms_runlock_fallback(struct rmslock *rms) { Modified: head/sys/sys/rmlock.h ============================================================================== --- head/sys/sys/rmlock.h Fri Jan 31 08:36:23 2020 (r357319) +++ head/sys/sys/rmlock.h Fri Jan 31 08:36:49 2020 (r357320) @@ -136,9 +136,21 @@ struct rm_args { void rms_init(struct rmslock *rms, const char *name); void rms_destroy(struct rmslock *rms); void rms_rlock(struct rmslock *rms); +int rms_try_rlock(struct rmslock *rms); void rms_runlock(struct rmslock *rms); void rms_wlock(struct rmslock *rms); void rms_wunlock(struct rmslock *rms); + +/* + * Writers are not explicitly tracked, thus until that changes the best we can + * do is indicate the lock is taken for writing by *someone*. + */ +static inline int +rms_wowned(struct rmslock *rms) +{ + + return (rms->writers > 0); +} #endif /* _KERNEL */ #endif /* !_SYS_RMLOCK_H_ */