x86: change_page_attr bandaids

- Disable CLFLUSH again; it is still broken. Always do WBINVD.
- Always flush in the i386 case, not only when there are deferred pages.

These are both brute-force inefficient fixes, to be improved
next release cycle.

The changes to i386 are a little more extensive than strictly
needed (some dead code added), but it is more similar to the x86-64 version
now and the dead code will be used soon.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 3 deletions

diff --git a/arch/x86_64/mm/pageattr.c b/arch/x86_64/mm/pageattr.c
index d653d0bf3df6..9148f4a4cec6 100644
--- a/arch/x86_64/mm/pageattr.c
+++ b/arch/x86_64/mm/pageattr.c
@@ -74,10 +74,11 @@ static void flush_kernel_map(void *arg)
         struct page *pg;
 
         /* When clflush is available always use it because it is
-           much cheaper than WBINVD */
-        if (!cpu_has_clflush)
+           much cheaper than WBINVD. Disable clflush for now because
+           the high level code is not ready yet */
+        if (1 || !cpu_has_clflush)
                 asm volatile("wbinvd" ::: "memory");
-        list_for_each_entry(pg, l, lru) {
+        else list_for_each_entry(pg, l, lru) {
                 void *adr = page_address(pg);
                 if (cpu_has_clflush)
                         cache_flush_page(adr);