Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758654AbZJELsE (ORCPT ); Mon, 5 Oct 2009 07:48:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758559AbZJELsC (ORCPT ); Mon, 5 Oct 2009 07:48:02 -0400 Received: from hera.kernel.org ([140.211.167.34]:56754 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758458AbZJELr5 (ORCPT ); Mon, 5 Oct 2009 07:47:57 -0400 Date: Mon, 5 Oct 2009 11:46:53 GMT From: tip-bot for john stultz Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, jkacur@redhat.com, williams@redhat.com, johnstul@us.ibm.com, schwidefsky@de.ibm.com, akpm@linux-foundation.org, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, jkacur@redhat.com, johnstul@us.ibm.com, williams@redhat.com, schwidefsky@de.ibm.com, akpm@linux-foundation.org, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <1254525855.7741.95.camel@localhost.localdomain> References: <1254525855.7741.95.camel@localhost.localdomain> To: linux-tip-commits@vger.kernel.org Subject: [tip:timers/core] time: Remove xtime_cache Message-ID: Git-Commit-ID: 5335c1c371aa32fcef97c4979f04b065772194ab X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Mon, 05 Oct 2009 11:46:54 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4887 Lines: 164 Commit-ID: 5335c1c371aa32fcef97c4979f04b065772194ab Gitweb: http://git.kernel.org/tip/5335c1c371aa32fcef97c4979f04b065772194ab Author: john stultz AuthorDate: Fri, 2 Oct 2009 16:24:15 -0700 Committer: Ingo Molnar CommitDate: Sun, 4 Oct 2009 19:31:39 +0200 time: Remove xtime_cache With the prior logarithmic time accumulation patch, xtime will now always be within one "tick" of the current time, instead of possibly half a second off. This removes the need for the xtime_cache value, which always stored the time at the last interrupt, so this patch cleans that up removing the xtime_cache related code. This is a bit simpler, but still could use some wider testing. Signed-off-by: John Stultz Acked-by: Thomas Gleixner Cc: John Kacur Cc: Clark Williams Cc: Martin Schwidefsky Cc: Andrew Morton LKML-Reference: <1254525855.7741.95.camel@localhost.localdomain> Signed-off-by: Ingo Molnar --- kernel/time.c | 1 - kernel/time/timekeeping.c | 27 ++++----------------------- 2 files changed, 4 insertions(+), 24 deletions(-) diff --git a/kernel/time.c b/kernel/time.c index 2e2e469..2ef4fe2 100644 --- a/kernel/time.c +++ b/kernel/time.c @@ -136,7 +136,6 @@ static inline void warp_clock(void) write_seqlock_irq(&xtime_lock); wall_to_monotonic.tv_sec -= sys_tz.tz_minuteswest * 60; xtime.tv_sec += sys_tz.tz_minuteswest * 60; - update_xtime_cache(0); write_sequnlock_irq(&xtime_lock); clock_was_set(); } diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 5fdd78e..96b3f0d 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -164,13 +164,6 @@ struct timespec raw_time; /* flag for if timekeeping is suspended */ int __read_mostly timekeeping_suspended; -static struct timespec xtime_cache __attribute__ ((aligned (16))); -void update_xtime_cache(u64 nsec) -{ - xtime_cache = xtime; - timespec_add_ns(&xtime_cache, nsec); -} - /* must hold xtime_lock */ void timekeeping_leap_insert(int leapsecond) { @@ -331,8 +324,6 @@ int do_settimeofday(struct timespec *tv) xtime = *tv; - update_xtime_cache(0); - timekeeper.ntp_error = 0; ntp_clear(); @@ -547,7 +538,6 @@ void __init timekeeping_init(void) } set_normalized_timespec(&wall_to_monotonic, -boot.tv_sec, -boot.tv_nsec); - update_xtime_cache(0); total_sleep_time.tv_sec = 0; total_sleep_time.tv_nsec = 0; write_sequnlock_irqrestore(&xtime_lock, flags); @@ -581,7 +571,6 @@ static int timekeeping_resume(struct sys_device *dev) wall_to_monotonic = timespec_sub(wall_to_monotonic, ts); total_sleep_time = timespec_add_safe(total_sleep_time, ts); } - update_xtime_cache(0); /* re-base the last cycle value */ timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock); timekeeper.ntp_error = 0; @@ -721,7 +710,6 @@ static void timekeeping_adjust(s64 offset) timekeeper.ntp_error_shift; } - /** * logarithmic_accumulation - shifted accumulation of cycles * @@ -765,7 +753,6 @@ static cycle_t logarithmic_accumulation(cycle_t offset, int shift) return offset; } - /** * update_wall_time - Uses the current clocksource to increment the wall time * @@ -775,7 +762,6 @@ void update_wall_time(void) { struct clocksource *clock; cycle_t offset; - u64 nsecs; int shift = 0, maxshift; /* Make sure we're fully resumed: */ @@ -841,9 +827,6 @@ void update_wall_time(void) timekeeper.ntp_error += timekeeper.xtime_nsec << timekeeper.ntp_error_shift; - nsecs = clocksource_cyc2ns(offset, timekeeper.mult, timekeeper.shift); - update_xtime_cache(nsecs); - /* check to see if there is a new clocksource to use */ update_vsyscall(&xtime, timekeeper.clock); } @@ -880,13 +863,13 @@ void monotonic_to_bootbased(struct timespec *ts) unsigned long get_seconds(void) { - return xtime_cache.tv_sec; + return xtime.tv_sec; } EXPORT_SYMBOL(get_seconds); struct timespec __current_kernel_time(void) { - return xtime_cache; + return xtime; } struct timespec current_kernel_time(void) @@ -896,8 +879,7 @@ struct timespec current_kernel_time(void) do { seq = read_seqbegin(&xtime_lock); - - now = xtime_cache; + now = xtime; } while (read_seqretry(&xtime_lock, seq)); return now; @@ -911,8 +893,7 @@ struct timespec get_monotonic_coarse(void) do { seq = read_seqbegin(&xtime_lock); - - now = xtime_cache; + now = xtime; mono = wall_to_monotonic; } while (read_seqretry(&xtime_lock, seq)); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/