[RFC] Patches to reduce delay in arch/kernel/time.c

From: Nigel Cunningham
Date: Sat Jan 08 2005 - 05:03:42 EST


Hi all.

Over the past couple of months there's been a fair bit of discussion
regarding clock drift after suspending, big pauses during suspending and
resuming and so on. I believe this set of three patches, applied on top
of David's patch (now in Linus' tree) may address the remaining issues.
Comments please!

Patch 1: Replace multiple calls to get_cmos_time in both suspend and
resume routines with a single call. Since get_cmos_time waits for the
start of the next second before returning the result, This
reduces the delay for suspending and resuming by one second in each
case.
Patch 2: Make sleep start an unsigned long. This appears to address the
occasional 1hr 10min error seen by myself and John
(http://lkml.org/lkml/2004/12/15/290). Better solution?
Patch 3: Implement a new __get_cmos_time() function which doesn't delay
until the start of the new second before returning. Use it in suspending
(feel free to correct me, but I don't think having the
exact start of the second is necessary here).

Regards,

Nigel
--
Nigel Cunningham
Software Engineer, Canberra, Australia
http://www.cyclades.com

Ph: +61 (2) 6292 8028 Mob: +61 (417) 100 574

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