| From | Paul Gortmaker <> | Subject | [34-longterm 059/247] fix jiffy calculations in calibrate_delay_direct to handle overflow | Date | Thu, 23 Jun 2011 13:25:58 -0400 |
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From: Tim Deegan <Tim.Deegan@citrix.com>
------------------- This is a commit scheduled for the next v2.6.34 longterm release. If you see a problem with using this for longterm, please comment. -------------------
commit 70a062286b9dfcbd24d2e11601aecfead5cf709a upstream.
Fixes a hang when booting as dom0 under Xen, when jiffies can be quite large by the time the kernel init gets this far.
Signed-off-by: Tim Deegan <Tim.Deegan@citrix.com> [jbeulich@novell.com: !time_after() -> time_before_eq() as suggested by Jiri Slaby] Signed-off-by: Jan Beulich <jbeulich@novell.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> --- init/calibrate.c | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/init/calibrate.c b/init/calibrate.c index 6eb48e5..24fe022 100644 --- a/init/calibrate.c +++ b/init/calibrate.c @@ -66,7 +66,7 @@ static unsigned long __cpuinit calibrate_delay_direct(void) pre_start = 0; read_current_timer(&start); start_jiffies = jiffies; - while (jiffies <= (start_jiffies + 1)) { + while (time_before_eq(jiffies, start_jiffies + 1)) { pre_start = start; read_current_timer(&start); } @@ -74,8 +74,8 @@ static unsigned long __cpuinit calibrate_delay_direct(void) pre_end = 0; end = post_start; - while (jiffies <= - (start_jiffies + 1 + DELAY_CALIBRATION_TICKS)) { + while (time_before_eq(jiffies, start_jiffies + 1 + + DELAY_CALIBRATION_TICKS)) { pre_end = end; read_current_timer(&end); } -- 1.7.4.4
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