Techwizz/kernel-fxtec-pro1x
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

Revert "sys_time() speedup"

Browse source 
This basically reverts commit 4e44f3497d,
while waiting for it to be re-done more completely.  There are cases of
people mixing "time()" with higher-resolution time sources, and we need
to take the nanosecond offsets into account.

Ingo has a patch that does that, but it's still under some discussion.
In the meantime, just revert back to the old simple situation of just
doing the whole exact timesource calculations.

But rather than using do_gettimeofday(), use the internal nanosecond
resolution getnstimeofday(), which at least avoids one unnecessary
conversion (since we really don't care about whether the fractional
seconds are nanoseconds or microseconds - we'll just throw them away).

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Linus Torvalds 2007-07-20 13:28:54 -07:00
parent 1d4ec7b1d6
commit 2008220879
1 changed files with 5 additions and 8 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

13
kernel/time.c
View file

@ -57,17 +57,14 @@ EXPORT_SYMBOL(sys_tz);
*/
asmlinkage long sys_time(time_t __user * tloc)
{
/*
* We read xtime.tv_sec atomically - it's updated
* atomically by update_wall_time(), so no need to
* even read-lock the xtime seqlock:
*/
time_t i = xtime.tv_sec;
time_t i;
struct timespec tv;
smp_rmb(); /* sys_time() results are coherent */
getnstimeofday(&tv);
i = tv.tv_sec;
if (tloc) {
if (put_user(i, tloc))
if (put_user(i,tloc))
i = -EFAULT;
}
return i;