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SubjectRe: gettimeofday non-monotonic on 2.2.7 SMP
 =>From: Andrea Arcangeli <andrea@suse.de>
=>...
=>Instead of adding tricky debugging code into the kernel could you try to
=>run again your userspace proggy and see if it continues to generate
=>errors? Checking the retval of gettimeofday from userspace or from the
=>kernel make no one difference. gettimeofday won't run in irq handlers if
=>called from usersapce.
=>
=>Could you try if your old proggy (that looked strightforward to me)
=>continue to complains or not with my recover-lost-ticks code applyed?

Sure. I compiled a fresh 2.3.3+2.3.3_andrea1+your_extra_log_msg, and
(while scrolling an X window) my time checker reports:

Thu May 20 14:59:29 1999: fwd:877179/9:back max 0000003
Thu May 20 14:59:30 1999: fwd:830353/11:back max 0007821
Thu May 20 14:59:31 1999: fwd:855415/10:back max 0006035
Thu May 20 14:59:32 1999: fwd:877045/10:back max 0000003
Thu May 20 14:59:33 1999: fwd:877482/9:back max 0000003
at about the same time as your log message is going off:

May 20 14:59:29 vheissu kernel: recover_lost_timer: lost 1 tick from c010de2f process X pid 419
May 20 14:59:30 vheissu kernel: recover_lost_timer: lost 1 tick from 08262682 process netscape pid 492
May 20 14:59:30 vheissu kernel: recover_lost_timer: lost 1 tick from c01bf9e0 process X pid 419

If I turn off xntpd, then my time checker only reports time decrements
when I'm scrolling or moving X windows around. All the warps I saw
were between 1 and 10ms. I don't always see a "recover_lost_timer"
message with a time warp (in fact, I thought that perhaps xntpd was
confusing recover_lost_timer, but after more scrolling, I saw some
lost ticks even though xntpd was off).

regards,
d.

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