diff options
| author | Karel Zak | 2008-10-16 23:37:38 +0200 |
|---|---|---|
| committer | Karel Zak | 2008-10-16 23:37:38 +0200 |
| commit | 433c8bea8a4047aec35d894a3283853d1a48f897 (patch) | |
| tree | ef8546e25bc84daa74c4470614dafe1895c7c152 /hwclock/cmos.c | |
| parent | ipcs: fix exit codes, remove tailing white-spaces (diff) | |
| download | kernel-qcow2-util-linux-433c8bea8a4047aec35d894a3283853d1a48f897.tar.gz kernel-qcow2-util-linux-433c8bea8a4047aec35d894a3283853d1a48f897.tar.xz kernel-qcow2-util-linux-433c8bea8a4047aec35d894a3283853d1a48f897.zip | |
hwclock: remove "cli" and "sti" from i386 CMOS code
The protection against context switch is nonsense. There is possible
to optimize the access to CMOS by mlockall(MCL_CURRENT) and SCHED_FIFO.
For more details see: http://lkml.org/lkml/2008/10/12/132
Reported-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Karel Zak <kzak@redhat.com>
Diffstat (limited to 'hwclock/cmos.c')
| -rw-r--r-- | hwclock/cmos.c | 29 |
1 files changed, 4 insertions, 25 deletions
diff --git a/hwclock/cmos.c b/hwclock/cmos.c index c45a5045e..8b3495b7e 100644 --- a/hwclock/cmos.c +++ b/hwclock/cmos.c @@ -216,30 +216,7 @@ set_cmos_access(int Jensen, int funky_toy) { #endif - - -#ifdef __i386__ - -/* - * Try to do CMOS access atomically, so that no other processes - * can get a time slice while we are reading or setting the clock. - * (Also, if the kernel time is synchronized with an external source, - * the kernel itself will fiddle with the RTC every 11 minutes.) - */ - -static unsigned long -atomic(const char *name, unsigned long (*op)(unsigned long), - unsigned long arg) -{ - unsigned long v; - __asm__ volatile ("cli"); - v = (*op)(arg); - __asm__ volatile ("sti"); - return v; -} - -#elif __alpha__ - +#if __alpha__ /* * The Alpha doesn't allow user-level code to disable interrupts (for * good reasons). Instead, we ensure atomic operation by performing @@ -267,12 +244,14 @@ atomic(const char *name, unsigned long (*op)(unsigned long), fprintf(stderr, _("%s: atomic %s failed for 1000 iterations!"), progname, name); exit(1); } - #else /* * Hmmh, this isn't very atomic. Maybe we should force an error * instead? + * + * TODO: optimize the access to CMOS by mlockall(MCL_CURRENT) + * and SCHED_FIFO */ static unsigned long atomic(const char *name, unsigned long (*op)(unsigned long), |