From patchwork Tue Nov 15 04:04:00 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Stultz X-Patchwork-Id: 5111 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 E5A1923EF5 for ; Tue, 15 Nov 2011 04:04:27 +0000 (UTC) Received: from mail-fx0-f52.google.com (mail-fx0-f52.google.com [209.85.161.52]) by fiordland.canonical.com (Postfix) with ESMTP id DB22BA181D1 for ; Tue, 15 Nov 2011 04:04:27 +0000 (UTC) Received: by mail-fx0-f52.google.com with SMTP id a26so64372faa.11 for ; Mon, 14 Nov 2011 20:04:27 -0800 (PST) Received: by 10.152.144.136 with SMTP id sm8mr15987626lab.33.1321329867699; Mon, 14 Nov 2011 20:04:27 -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 10.152.41.198 with SMTP id h6cs24728lal; Mon, 14 Nov 2011 20:04:27 -0800 (PST) Received: by 10.42.117.193 with SMTP id u1mr25908875icq.24.1321329863743; Mon, 14 Nov 2011 20:04:23 -0800 (PST) Received: from e1.ny.us.ibm.com (e1.ny.us.ibm.com. 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Violators will be prosecuted; Mon, 14 Nov 2011 23:04:21 -0500 Received: from d01av02.pok.ibm.com (d01av02.pok.ibm.com [9.56.224.216]) by d01relay03.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id pAF44K97266140; Mon, 14 Nov 2011 23:04:20 -0500 Received: from d01av02.pok.ibm.com (loopback [127.0.0.1]) by d01av02.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id pAF44Jgn012883; Tue, 15 Nov 2011 02:04:20 -0200 Received: from kernel.beaverton.ibm.com ([9.47.67.96]) by d01av02.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id pAF44JLt012871; Tue, 15 Nov 2011 02:04:19 -0200 Received: by kernel.beaverton.ibm.com (Postfix, from userid 1056) id D73481E7506; Mon, 14 Nov 2011 20:04:17 -0800 (PST) From: John Stultz To: LKML Cc: John Stultz , Thomas Gleixner , Eric Dumazet , Richard Cochran Subject: [PATCH 10/16] time: Remove most of xtime_lock usage in timekeeping.c Date: Mon, 14 Nov 2011 20:04:00 -0800 Message-Id: <1321329846-14755-11-git-send-email-john.stultz@linaro.org> X-Mailer: git-send-email 1.7.3.2.146.gca209 In-Reply-To: <1321329846-14755-1-git-send-email-john.stultz@linaro.org> References: <1321329846-14755-1-git-send-email-john.stultz@linaro.org> x-cbid: 11111504-6078-0000-0000-000004657EEC Now that ntp.c's locking is reworked, we can remove most of the xtime_lock usage in timekeeping.c The remaining xtime_lock presence is really for jiffies access and the global load calculation. CC: Thomas Gleixner CC: Eric Dumazet CC: Richard Cochran Signed-off-by: John Stultz --- kernel/time/timekeeping.c | 44 +++++++++++++++----------------------------- 1 files changed, 15 insertions(+), 29 deletions(-) diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index f92e636..810b974 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -172,7 +172,6 @@ static inline s64 timekeeping_get_ns_raw(void) return clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); } -/* must hold xtime_lock */ void timekeeping_leap_insert(int leapsecond) { unsigned long flags; @@ -368,13 +367,12 @@ EXPORT_SYMBOL(do_gettimeofday); int do_settimeofday(const struct timespec *tv) { struct timespec ts_delta; - unsigned long flags1,flags2; + unsigned long flags; if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) return -EINVAL; - write_seqlock_irqsave(&xtime_lock, flags1); - write_seqlock_irqsave(&timekeeper.lock, flags2); + write_seqlock_irqsave(&timekeeper.lock, flags); timekeeping_forward_now(); @@ -391,8 +389,7 @@ int do_settimeofday(const struct timespec *tv) update_vsyscall(&timekeeper.xtime, &timekeeper.wall_to_monotonic, timekeeper.clock, timekeeper.mult); - write_sequnlock_irqrestore(&timekeeper.lock, flags2); - write_sequnlock_irqrestore(&xtime_lock, flags1); + write_sequnlock_irqrestore(&timekeeper.lock, flags); /* signal hrtimers about time change */ clock_was_set(); @@ -411,13 +408,12 @@ EXPORT_SYMBOL(do_settimeofday); */ int timekeeping_inject_offset(struct timespec *ts) { - unsigned long flags1,flags2; + unsigned long flags; if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC) return -EINVAL; - write_seqlock_irqsave(&xtime_lock, flags1); - write_seqlock_irqsave(&timekeeper.lock, flags2); + write_seqlock_irqsave(&timekeeper.lock, flags); timekeeping_forward_now(); @@ -431,8 +427,7 @@ int timekeeping_inject_offset(struct timespec *ts) update_vsyscall(&timekeeper.xtime, &timekeeper.wall_to_monotonic, timekeeper.clock, timekeeper.mult); - write_sequnlock_irqrestore(&timekeeper.lock, flags2); - write_sequnlock_irqrestore(&xtime_lock, flags1); + write_sequnlock_irqrestore(&timekeeper.lock, flags); /* signal hrtimers about time change */ clock_was_set(); @@ -594,9 +589,7 @@ void __init timekeeping_init(void) seqlock_init(&timekeeper.lock); - write_seqlock_irqsave(&xtime_lock, flags); ntp_init(); - write_sequnlock_irqrestore(&xtime_lock, flags); write_seqlock_irqsave(&timekeeper.lock, flags); clock = clocksource_default_clock(); @@ -657,7 +650,7 @@ static void __timekeeping_inject_sleeptime(struct timespec *delta) */ void timekeeping_inject_sleeptime(struct timespec *delta) { - unsigned long flags1,flags2; + unsigned long flags; struct timespec ts; /* Make sure we don't set the clock twice */ @@ -665,8 +658,7 @@ void timekeeping_inject_sleeptime(struct timespec *delta) if (!(ts.tv_sec == 0 && ts.tv_nsec == 0)) return; - write_seqlock_irqsave(&xtime_lock, flags1); - write_seqlock_irqsave(&timekeeper.lock, flags2); + write_seqlock_irqsave(&timekeeper.lock, flags); timekeeping_forward_now(); @@ -677,8 +669,7 @@ void timekeeping_inject_sleeptime(struct timespec *delta) update_vsyscall(&timekeeper.xtime, &timekeeper.wall_to_monotonic, timekeeper.clock, timekeeper.mult); - write_sequnlock_irqrestore(&timekeeper.lock, flags2); - write_sequnlock_irqrestore(&xtime_lock, flags1); + write_sequnlock_irqrestore(&timekeeper.lock, flags); /* signal hrtimers about time change */ clock_was_set(); @@ -694,15 +685,14 @@ void timekeeping_inject_sleeptime(struct timespec *delta) */ static void timekeeping_resume(void) { - unsigned long flags1,flags2; + unsigned long flags; struct timespec ts; read_persistent_clock(&ts); clocksource_resume(); - write_seqlock_irqsave(&xtime_lock, flags1); - write_seqlock_irqsave(&timekeeper.lock, flags2); + write_seqlock_irqsave(&timekeeper.lock, flags); if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) { ts = timespec_sub(ts, timekeeping_suspend_time); @@ -712,8 +702,7 @@ static void timekeeping_resume(void) timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock); timekeeper.ntp_error = 0; timekeeping_suspended = 0; - write_sequnlock_irqrestore(&timekeeper.lock, flags2); - write_sequnlock_irqrestore(&xtime_lock, flags1); + write_sequnlock_irqrestore(&timekeeper.lock, flags); touch_softlockup_watchdog(); @@ -725,14 +714,13 @@ static void timekeeping_resume(void) static int timekeeping_suspend(void) { - unsigned long flags1,flags2; + unsigned long flags; struct timespec delta, delta_delta; static struct timespec old_delta; read_persistent_clock(&timekeeping_suspend_time); - write_seqlock_irqsave(&xtime_lock, flags1); - write_seqlock_irqsave(&timekeeper.lock, flags2); + write_seqlock_irqsave(&timekeeper.lock, flags); timekeeping_forward_now(); timekeeping_suspended = 1; @@ -755,8 +743,7 @@ static int timekeeping_suspend(void) timekeeping_suspend_time = timespec_add(timekeeping_suspend_time, delta_delta); } - write_sequnlock_irqrestore(&timekeeper.lock, flags2); - write_sequnlock_irqrestore(&xtime_lock, flags1); + write_sequnlock_irqrestore(&timekeeper.lock, flags); clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL); clocksource_suspend(); @@ -916,7 +903,6 @@ static cycle_t logarithmic_accumulation(cycle_t offset, int shift) /** * update_wall_time - Uses the current clocksource to increment the wall time * - * Called from the timer interrupt, must hold a write on xtime_lock. */ static void update_wall_time(void) {