Re: [PATCH 4/8] time: Condense timekeeper.xtime into xtime_sec

From: Andreas Schwab
Date: Sun Aug 19 2012 - 17:03:14 EST


John Stultz <john.stultz@xxxxxxxxxx> writes:

> The timekeeper struct has a xtime_nsec, which keeps the
> sub-nanosecond remainder. This ends up being somewhat
> duplicative of the timekeeper.xtime.tv_nsec value, and we
> have to do extra work to keep them apart, copying the full
> nsec portion out and back in over and over.
>
> This patch simplifies some of the logic by taking the timekeeper
> xtime value and splitting it into timekeeper.xtime_sec and
> reuses the timekeeper.xtime_nsec for the sub-second portion
> (stored in higher res shifted nanoseconds).
>
> This simplifies some of the accumulation logic. And will
> allow for more accurate timekeeping once the vsyscall code
> is updated to use the shifted nanosecond remainder.

This (together with b44d50d "time: Fix casting issue in tk_set_xtime and
tk_xtime_add") is causing resume to hang on the iBook (PowerBook6,7).
The fact that the add-on commit is needed to uncover the bug might give
a hint, but I'm unable to decipher it.

Andreas.

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