From patchwork Tue Mar 6 09:57:35 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lai Jiangshan X-Patchwork-Id: 7107 Return-Path: X-Original-To: patchwork@peony.canonical.com Delivered-To: patchwork@peony.canonical.com Received: from fiordland.canonical.com (fiordland.canonical.com [91.189.94.145]) by peony.canonical.com (Postfix) with ESMTP id 9D54C23E64 for ; Tue, 6 Mar 2012 09:53:17 +0000 (UTC) Received: from mail-iy0-f180.google.com (mail-iy0-f180.google.com [209.85.210.180]) by fiordland.canonical.com (Postfix) with ESMTP id 66B72A182F9 for ; Tue, 6 Mar 2012 09:53:17 +0000 (UTC) Received: by mail-iy0-f180.google.com with SMTP id e36so9163325iag.11 for ; Tue, 06 Mar 2012 01:53:17 -0800 (PST) Received: from mr.google.com ([10.50.42.132]) by 10.50.42.132 with SMTP id o4mr9646398igl.58.1331027597258 (num_hops = 1); Tue, 06 Mar 2012 01:53:17 -0800 (PST) MIME-Version: 1.0 Received: by 10.50.42.132 with SMTP id o4mr7991917igl.58.1331027597116; Tue, 06 Mar 2012 01:53:17 -0800 (PST) X-Forwarded-To: linaro-patchwork@canonical.com X-Forwarded-For: patch@linaro.org linaro-patchwork@canonical.com Delivered-To: patches@linaro.org Received: by 10.231.53.18 with SMTP id k18csp52108ibg; Tue, 6 Mar 2012 01:53:16 -0800 (PST) Received: by 10.68.227.99 with SMTP id rz3mr48053324pbc.39.1331027596226; Tue, 06 Mar 2012 01:53:16 -0800 (PST) Received: from song.cn.fujitsu.com ([222.73.24.84]) by mx.google.com with ESMTP id 9si19671304pbr.108.2012.03.06.01.53.15; Tue, 06 Mar 2012 01:53:16 -0800 (PST) Received-SPF: neutral (google.com: 222.73.24.84 is neither permitted nor denied by best guess record for domain of laijs@cn.fujitsu.com) client-ip=222.73.24.84; Authentication-Results: mx.google.com; spf=neutral (google.com: 222.73.24.84 is neither permitted nor denied by best guess record for domain of laijs@cn.fujitsu.com) smtp.mail=laijs@cn.fujitsu.com X-IronPort-AV: E=Sophos;i="4.73,539,1325433600"; d="scan'208";a="4464393" Received: from unknown (HELO tang.cn.fujitsu.com) ([10.167.250.3]) by song.cn.fujitsu.com with ESMTP; 06 Mar 2012 17:53:10 +0800 Received: from mailserver.fnst.cn.fujitsu.com (tang.cn.fujitsu.com [127.0.0.1]) by tang.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id q269rASJ019494; Tue, 6 Mar 2012 17:53:11 +0800 Received: from localhost.localdomain ([10.167.225.146]) by mailserver.fnst.cn.fujitsu.com (Lotus Domino Release 8.5.1FP4) with ESMTP id 2012030617511668-893319 ; Tue, 6 Mar 2012 17:51:16 +0800 From: Lai Jiangshan To: "Paul E. McKenney" Cc: Lai Jiangshan , linux-kernel@vger.kernel.org, mingo@elte.hu, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, josh@joshtriplett.org, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, eric.dumazet@gmail.com, darren@dvhart.com, fweisbec@gmail.com, patches@linaro.org Subject: [PATCH 3/6] use "int trycount" instead of "bool expedited" Date: Tue, 6 Mar 2012 17:57:35 +0800 Message-Id: <1331027858-7648-3-git-send-email-laijs@cn.fujitsu.com> X-Mailer: git-send-email 1.7.4.4 In-Reply-To: <1331027858-7648-1-git-send-email-laijs@cn.fujitsu.com> References: <1331023359-6987-1-git-send-email-laijs@cn.fujitsu.com> <1331027858-7648-1-git-send-email-laijs@cn.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2012-03-06 17:51:16, Serialize by Router on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2012-03-06 17:51:20, Serialize complete at 2012-03-06 17:51:20 X-Gm-Message-State: ALoCoQkySvKTPxiuyopP5kqBNOdmGrGRppsVHw2zpZPSQ4GhicIsjhQD/F0nWty77JfGqzxjUpxp Signed-off-by: Lai Jiangshan --- kernel/srcu.c | 27 ++++++++++++++------------- 1 files changed, 14 insertions(+), 13 deletions(-) diff --git a/kernel/srcu.c b/kernel/srcu.c index fbe2d5f..d5f3450 100644 --- a/kernel/srcu.c +++ b/kernel/srcu.c @@ -254,12 +254,12 @@ EXPORT_SYMBOL_GPL(__srcu_read_unlock); * we repeatedly block for 1-millisecond time periods. This approach * has done well in testing, so there is no need for a config parameter. */ -#define SYNCHRONIZE_SRCU_READER_DELAY 5 +#define SYNCHRONIZE_SRCU_READER_DELAY 5 +#define SYNCHRONIZE_SRCU_TRYCOUNT 2 +#define SYNCHRONIZE_SRCU_EXP_TRYCOUNT 12 -static void wait_idx(struct srcu_struct *sp, int idx, bool expedited) +static void wait_idx(struct srcu_struct *sp, int idx, int trycount) { - int trycount = 0; - /* * If a reader fetches the index before the ->completed increment, * but increments its counter after srcu_readers_active_idx_check() @@ -278,9 +278,10 @@ static void wait_idx(struct srcu_struct *sp, int idx, bool expedited) if (!srcu_readers_active_idx_check(sp, idx)) { udelay(SYNCHRONIZE_SRCU_READER_DELAY); while (!srcu_readers_active_idx_check(sp, idx)) { - if (expedited && ++ trycount < 10) + if (trycount > 0) { + trycount--; udelay(SYNCHRONIZE_SRCU_READER_DELAY); - else + } else schedule_timeout_interruptible(1); } } @@ -310,18 +311,18 @@ static void wait_idx(struct srcu_struct *sp, int idx, bool expedited) * by the next __synchronize_srcu() invoking wait_idx() for such readers * before starting a new grace period. */ -static void flip_idx_and_wait(struct srcu_struct *sp, bool expedited) +static void flip_idx_and_wait(struct srcu_struct *sp, int trycount) { int idx; idx = sp->completed++ & 0x1; - wait_idx(sp, idx, expedited); + wait_idx(sp, idx, trycount); } /* * Helper function for synchronize_srcu() and synchronize_srcu_expedited(). */ -static void __synchronize_srcu(struct srcu_struct *sp, bool expedited) +static void __synchronize_srcu(struct srcu_struct *sp, int trycount) { rcu_lockdep_assert(!lock_is_held(&sp->dep_map) && !lock_is_held(&rcu_bh_lock_map) && @@ -357,14 +358,14 @@ static void __synchronize_srcu(struct srcu_struct *sp, bool expedited) * fetching ->completed and incrementing their counter, wait_idx() * will normally not need to wait. */ - wait_idx(sp, (sp->completed - 1) & 0x1, expedited); + wait_idx(sp, (sp->completed - 1) & 0x1, trycount); /* * Now that wait_idx() has waited for the really old readers, * invoke flip_idx_and_wait() to flip the counter and wait * for current SRCU readers. */ - flip_idx_and_wait(sp, expedited); + flip_idx_and_wait(sp, trycount); mutex_unlock(&sp->mutex); } @@ -385,7 +386,7 @@ static void __synchronize_srcu(struct srcu_struct *sp, bool expedited) */ void synchronize_srcu(struct srcu_struct *sp) { - __synchronize_srcu(sp, 0); + __synchronize_srcu(sp, SYNCHRONIZE_SRCU_TRYCOUNT); } EXPORT_SYMBOL_GPL(synchronize_srcu); @@ -406,7 +407,7 @@ EXPORT_SYMBOL_GPL(synchronize_srcu); */ void synchronize_srcu_expedited(struct srcu_struct *sp) { - __synchronize_srcu(sp, 1); + __synchronize_srcu(sp, SYNCHRONIZE_SRCU_EXP_TRYCOUNT); } EXPORT_SYMBOL_GPL(synchronize_srcu_expedited);