Re: [PATCH 1/8] posix clocks: introduce a syscall for clock tuning.
From: john stultz <hidden>
Date: 2010-09-23 19:50:47
Also in:
linux-api, linux-arm-kernel, linuxppc-dev, lkml, netdev
On Thu, 2010-09-23 at 19:31 +0200, Richard Cochran wrote:
A new syscall is introduced that allows tuning of a POSIX clock. The syscall is implemented for four architectures: arm, blackfin, powerpc, and x86. The new syscall, clock_adjtime, takes two parameters, the clock ID, and a pointer to a struct timex. The semantics of the timex struct have been expanded by one additional mode flag, which allows an absolute offset correction. When specificied, the clock offset is immediately corrected by adding the given time value to the current time value.
So I'd still split this patch up a little bit more. 1) Patch that implements the ADJ_SETOFFSET (*and its implementation*) in do_adjtimex. 2) Patch that adds the new syscall and clock_id multiplexing. 3) Patches that wire it up to the rest of the architectures (there's still a bunch missing here). And one little nit in the code:
quoted hunk ↗ jump to hunk
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c index 9ca4973..446b566 100644 --- a/kernel/posix-timers.c +++ b/kernel/posix-timers.c@@ -197,6 +197,14 @@ static int common_timer_create(struct k_itimer *new_timer) return 0; } +static inline int common_clock_adj(const clockid_t which_clock, struct timex *t) +{ + if (CLOCK_REALTIME == which_clock) + return do_adjtimex(t); + else + return -EOPNOTSUPP; +}
Would it make sense to point to the do_adjtimex() in the k_clock definition for CLOCK_REALTIME rather then conditionalizing it here? thanks -john