renegade-project/linux-next
2
0
Fork 0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-11-20 16:46:23 +08:00
Code

[MIPS] SMP: Get smp_tune_scheduling to do something useful.

Browse Source 
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Ralf Baechle 2007-02-21 00:10:19 +00:00
parent 9693a85378
commit de7fa296b6
1 changed files with 4 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
arch/mips/kernel/smp.c
View File

@ -51,31 +51,14 @@ int __cpu_logical_map[NR_CPUS]; /* Map logical to physical */
EXPORT_SYMBOL(phys_cpu_present_map); EXPORT_SYMBOL(phys_cpu_present_map);
EXPORT_SYMBOL(cpu_online_map); EXPORT_SYMBOL(cpu_online_map);
/* This happens early in bootup, can't really do it better */
static void smp_tune_scheduling (void) static void smp_tune_scheduling (void)
{ {
struct cache_desc *cd = &current_cpu_data.scache; struct cache_desc *cd = &current_cpu_data.scache;
unsigned long cachesize; /* kB */ unsigned long cachesize = cd->linesz * cd->sets * cd->ways;
unsigned long cpu_khz;
/* if (cachesize > max_cache_size)
* Crude estimate until we actually meassure ... max_cache_size = cachesize;
*/
cpu_khz = loops_per_jiffy * 2 * HZ / 1000;
/*
* Rough estimation for SMP scheduling, this is the number of
* cycles it takes for a fully memory-limited process to flush
* the SMP-local cache.
*
* (For a P5 this pretty much means we will choose another idle
* CPU almost always at wakeup time (this is due to the small
* L1 cache), on PIIs it's around 50-100 usecs, depending on
* the cache size)
*/
if (!cpu_khz)
return;
cachesize = cd->linesz * cd->sets * cd->ways;
} }
extern void __init calibrate_delay(void); extern void __init calibrate_delay(void);