On Thu, 10 Feb 2011, John David Anglin wrote:
> > The usual case would be just one address to flush. Would it be too
> > much overhead to do a prescan to determine if there are inequivalent
> > aliases before doing any flushes? I think I'll try this.
>
> Testing the following. Dropped debug message.
Although I didn't see any slow timer messages, I still had a number of
GCC testsuite timeouts. I didn't see these timeouts with interrupts
disabled. So, I plan to see if read write locks can be used without
disabling interrupts.
In any case, I believe it is useful to proceed with the parts of the
change where there is agreement. Note that the change to update_mmu_cache
is more than a optimization when parisc_requires_coherency is true as
the code no longer flushes when the pfn is not valid.
As noted, I'm seeing much improved stability on my rp3440 with this change.
Signed-off-by: John David Anglin <dave.anglin@xxxxxxxxxxxxxx>
Dave
--
J. David Anglin dave.anglin@xxxxxxxxxxxxxx
National Research Council of Canada (613) 990-0752 (FAX: 952-6602)
diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c
index 3f11331..e57c3e8 100644
--- a/arch/parisc/kernel/cache.c
+++ b/arch/parisc/kernel/cache.c
@@ -75,14 +75,16 @@ EXPORT_SYMBOL(flush_cache_all_local);
void
update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
{
- struct page *page = pte_page(*ptep);
+ unsigned long pfn = pte_pfn(*ptep);
+ struct page *page;
- if (pfn_valid(page_to_pfn(page)) && page_mapping(page) &&
- test_bit(PG_dcache_dirty, &page->flags)) {
+ if (!pfn_valid(pfn))
+ return;
- flush_kernel_dcache_page(page);
- clear_bit(PG_dcache_dirty, &page->flags);
- } else if (parisc_requires_coherency())
+ page = pfn_to_page(pfn);
+
+ if (test_and_clear_bit(PG_dcache_dirty, &page->flags)
+ || parisc_requires_coherency())
flush_kernel_dcache_page(page);
}
diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c
index c9b9322..f0cb56e 100644
--- a/arch/parisc/kernel/sys_parisc.c
+++ b/arch/parisc/kernel/sys_parisc.c
@@ -92,11 +92,12 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
{
if (len > TASK_SIZE)
return -ENOMEM;
- /* Might want to check for cache aliasing issues for MAP_FIXED case
- * like ARM or MIPS ??? --BenH.
- */
- if (flags & MAP_FIXED)
+ if (flags & MAP_FIXED) {
+ if ((flags & MAP_SHARED) &&
+ (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
+ return -EINVAL;
return addr;
+ }
if (!addr)
addr = TASK_UNMAPPED_BASE;
--
To unsubscribe from this list: send the line "unsubscribe linux-parisc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
