From: John Stultz <john.stultz@linaro.org>
To: lkml <linux-kernel@vger.kernel.org>
Cc: John Stultz <john.stultz@linaro.org>, Ingo Molnar <mingo@elte.hu>,
Thomas Gleixner <tglx@linutronix.de>,
Eric Dumazet <eric.dumazet@gmail.com>,
Richard Cochran <richardcochran@gmail.com>
Subject: [PATCH 9/9] time: Explicitly use u32 instead of int for shift values
Date: Thu, 1 Mar 2012 23:12:48 -0800 [thread overview]
Message-ID: <1330672368-32290-10-git-send-email-john.stultz@linaro.org> (raw)
In-Reply-To: <1330672368-32290-1-git-send-email-john.stultz@linaro.org>
Ingo noted that using a u32 instead of int for shift values
would be better to make sure the compiler doesn't unnecessarily
use complex signed arithmetic.
CC: Ingo Molnar <mingo@elte.hu>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
kernel/time/timekeeping.c | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 67983ff..60351a8 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -28,7 +28,7 @@ struct timekeeper {
/* NTP adjusted clock multiplier */
u32 mult;
/* The shift value of the current clocksource. */
- int shift;
+ u32 shift;
/* cycle value at last accumulation point */
cycle_t cycle_last;
/* Number of clock cycles in one NTP interval. */
@@ -48,7 +48,7 @@ struct timekeeper {
s64 ntp_error;
/* Shift conversion between clock shifted nano seconds and
* ntp shifted nano seconds. */
- int ntp_error_shift;
+ u32 ntp_error_shift;
/*
* wall_to_monotonic is what we need to add to xtime (or xtime corrected
* for sub jiffie times) to get to monotonic time. Monotonic is pegged
@@ -1016,7 +1016,7 @@ static void timekeeping_adjust(struct timekeeper *tk, s64 offset)
* Returns the unconsumed cycles.
*/
static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset,
- int shift)
+ u32 shift)
{
u64 nsecps = (u64)NSEC_PER_SEC << tk->shift;
u64 raw_nsecs;
--
1.7.3.2.146.gca209
prev parent reply other threads:[~2012-03-02 7:13 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-02 7:12 [PATCH 0/9] Reduce timekeeping lock hold time v2 John Stultz
2012-03-02 7:12 ` [PATCH 1/9] time: Condense timekeeper.xtime into xtime_sec John Stultz
2012-03-02 21:13 ` Christoph Lameter
2012-03-03 5:54 ` Richard Cochran
2012-03-02 7:12 ` [PATCH 2/9] time: Rework timekeeping functions to take timekeeper ptr as argument John Stultz
2012-03-02 7:12 ` [PATCH 3/9] time: Split timekeeper lock into separate reader/writer locks John Stultz
2012-03-02 7:12 ` [PATCH 4/9] time: Update timekeeper structure using a local shadow John Stultz
2012-03-02 7:38 ` Ingo Molnar
2012-03-02 7:53 ` John Stultz
2012-03-02 8:07 ` Ingo Molnar
2012-03-02 7:12 ` [PATCH 5/9] time: Shadow cycle_last in timekeeper structure John Stultz
2012-03-02 7:12 ` [PATCH 6/9] time: Reduce timekeeper read lock hold time John Stultz
2012-03-02 7:12 ` [PATCH 7/9] time: Convert the timekeeper's wlock to a raw_spin_lock John Stultz
2012-03-02 7:12 ` [PATCH 8/9] time: Whitespace cleanups per Ingo's requests John Stultz
2012-03-02 7:12 ` John Stultz [this message]
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