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authorPaul Mundt <lethal@linux-sh.org>2009-09-09 14:04:06 +0900
committerPaul Mundt <lethal@linux-sh.org>2009-09-09 14:04:06 +0900
commit654d364e26c797e8a5f9e2a1393607e6ca0106eb (patch)
tree69af9234533e6972404434d694272200c13477b8 /arch/sh/mm/cache.c
parent682f88ab74e55dae55ea3bf30b46f56f71b793bd (diff)
sh: sh4_flush_cache_mm() optimizations.
The i-cache flush in the case of VM_EXEC was added way back when as a sanity measure, and in practice we only care about evicting aliases from the d-cache. As a result, it's possible to drop the i-cache flush completely here. After careful profiling it's also come up that all of the work associated with hunting down aliases and doing ranged flushing ends up generating more overhead than simply blasting away the entire dcache, particularly if there are many mm's that need to be iterated over. As a result of that, just move back to flush_dcache_all() in these cases, which restores the old behaviour, and vastly simplifies the path. Additionally, on platforms without aliases at all, this can simply be nopped out. Presently we have the alias check in the SH-4 specific version, but this is true for all of the platforms, so move the check up to a generic location. This cuts down quite a bit on superfluous cacheop IPIs. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch/sh/mm/cache.c')
-rw-r--r--arch/sh/mm/cache.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/sh/mm/cache.c b/arch/sh/mm/cache.c
index 35c37b7f717..4aa92605453 100644
--- a/arch/sh/mm/cache.c
+++ b/arch/sh/mm/cache.c
@@ -164,11 +164,17 @@ void flush_cache_all(void)
void flush_cache_mm(struct mm_struct *mm)
{
+ if (boot_cpu_data.dcache.n_aliases == 0)
+ return;
+
cacheop_on_each_cpu(local_flush_cache_mm, mm, 1);
}
void flush_cache_dup_mm(struct mm_struct *mm)
{
+ if (boot_cpu_data.dcache.n_aliases == 0)
+ return;
+
cacheop_on_each_cpu(local_flush_cache_dup_mm, mm, 1);
}