* Re: [PATCH] fewer unlikely tests
2002-10-15 21:11 [PATCH] fewer unlikely tests Hugh Dickins
@ 2002-10-15 21:11 ` William Lee Irwin III
2002-10-16 0:40 ` David S. Miller
1 sibling, 0 replies; 3+ messages in thread
From: William Lee Irwin III @ 2002-10-15 21:11 UTC (permalink / raw)
To: Hugh Dickins; +Cc: Andrew Morton, linux-kernel
On Tue, Oct 15, 2002 at 10:11:44PM +0100, Hugh Dickins wrote:
> Occasionally I worry about all those BUG_ON tests we keep adding into
> page_alloc.c. This patch does one preliminary test of all the flags
> before trying individually. Maybe you consider this in bad taste,
> or maybe you think it's worthwhile: as you wish.
Reasonable and straightforward IMHO.
Bill
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH] fewer unlikely tests
@ 2002-10-15 21:11 Hugh Dickins
2002-10-15 21:11 ` William Lee Irwin III
2002-10-16 0:40 ` David S. Miller
0 siblings, 2 replies; 3+ messages in thread
From: Hugh Dickins @ 2002-10-15 21:11 UTC (permalink / raw)
To: Andrew Morton; +Cc: William Lee Irwin III, linux-kernel
Occasionally I worry about all those BUG_ON tests we keep adding into
page_alloc.c. This patch does one preliminary test of all the flags
before trying individually. Maybe you consider this in bad taste,
or maybe you think it's worthwhile: as you wish.
--- 2.5.42-mm3/mm/page_alloc.c Tue Oct 15 06:43:41 2002
+++ linux/mm/page_alloc.c Tue Oct 15 13:14:35 2002
@@ -125,12 +125,19 @@
static void free_pages_check(struct page *page)
{
- BUG_ON(PageLRU(page));
- BUG_ON(PagePrivate(page));
- BUG_ON(page->mapping != NULL);
- BUG_ON(PageLocked(page));
- BUG_ON(PageActive(page));
- BUG_ON(PageWriteback(page));
+ BUG_ON(page->mapping);
+ if (unlikely(page->flags & (
+ 1 << PG_lru |
+ 1 << PG_private |
+ 1 << PG_locked |
+ 1 << PG_active |
+ 1 << PG_writeback ))) {
+ BUG_ON(PageLRU(page));
+ BUG_ON(PagePrivate(page));
+ BUG_ON(PageLocked(page));
+ BUG_ON(PageActive(page));
+ BUG_ON(PageWriteback(page));
+ }
BUG_ON(page->pte.direct != 0);
if (PageDirty(page))
ClearPageDirty(page);
@@ -204,12 +211,20 @@
static struct page *prep_new_page(struct page *page)
{
BUG_ON(page->mapping);
- BUG_ON(PagePrivate(page));
- BUG_ON(PageLocked(page));
- BUG_ON(PageLRU(page));
- BUG_ON(PageActive(page));
- BUG_ON(PageDirty(page));
- BUG_ON(PageWriteback(page));
+ if (unlikely(page->flags & (
+ 1 << PG_private |
+ 1 << PG_locked |
+ 1 << PG_lru |
+ 1 << PG_active |
+ 1 << PG_dirty |
+ 1 << PG_writeback ))) {
+ BUG_ON(PagePrivate(page));
+ BUG_ON(PageLocked(page));
+ BUG_ON(PageLRU(page));
+ BUG_ON(PageActive(page));
+ BUG_ON(PageDirty(page));
+ BUG_ON(PageWriteback(page));
+ }
BUG_ON(page->pte.direct != 0);
page->flags &= ~(1 << PG_uptodate | 1 << PG_error |
1 << PG_referenced | 1 << PG_arch_1 |
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] fewer unlikely tests
2002-10-15 21:11 [PATCH] fewer unlikely tests Hugh Dickins
2002-10-15 21:11 ` William Lee Irwin III
@ 2002-10-16 0:40 ` David S. Miller
1 sibling, 0 replies; 3+ messages in thread
From: David S. Miller @ 2002-10-16 0:40 UTC (permalink / raw)
To: hugh; +Cc: akpm, wli, linux-kernel
From: Hugh Dickins <hugh@veritas.com>
Date: Tue, 15 Oct 2002 22:11:44 +0100 (BST)
Occasionally I worry about all those BUG_ON tests we keep adding into
page_alloc.c. This patch does one preliminary test of all the flags
before trying individually. Maybe you consider this in bad taste,
or maybe you think it's worthwhile: as you wish.
I definitely like this change.
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2002-10-16 0:42 UTC | newest]
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2002-10-15 21:11 ` William Lee Irwin III
2002-10-16 0:40 ` David S. Miller
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