Re: kernel BUG at page_alloc.c:98 -- compiling with distcc

Marcelo Tosatti
2004-04-29T21:14:05Z

On Tue, Apr 27, 2004 at 10:02:11PM -0400, Jeff Moyer wrote:
>
> >FYI, we see the exact same panic with the tg3 driver using 2.4.25 and
> >distcc with sendfile(). The bcm5700 driver also panics, but I haven't
> >captured a panic message to be certain it's the same bug.
>
> >kernel BUG at page_alloc.c:98!
>
> Andrea fixed this in his tree by deferring the page free to process context
> instead of BUG()ing on PageLRU(page).

Yeap, his fix looks OK.

Can you please people seeing the oops try this, from Andrea (on top of 2.4.26):

--- a/mm/page_alloc.c.orig 2004-04-29 17:38:14.184021976 -0300
+++ b/mm/page_alloc.c 2004-04-29 17:47:27.906843312 -0300
@@ -46,6 +46,34 @@

int vm_gfp_debug = 0;

+static void FASTCALL(__free_pages_ok (struct page *page, unsigned int order));
+
+static spinlock_t free_pages_ok_no_irq_lock = SPIN_LOCK_UNLOCKED;
+struct page * free_pages_ok_no_irq_head;
+
+static void do_free_pages_ok_no_irq(void * arg)
+{
+ struct page * page, * __page;
+
+ spin_lock_irq(&free_pages_ok_no_irq_lock);
+
+ page = free_pages_ok_no_irq_head;
+ free_pages_ok_no_irq_head = NULL;
+
+ spin_unlock_irq(&free_pages_ok_no_irq_lock);
+
+ while (page) {
+ __page = page;
+ page = page->next_hash;
+ __free_pages_ok(__page, __page->index);
+ }
+}
+
+static struct tq_struct free_pages_ok_no_irq_task = {
+ .routine = do_free_pages_ok_no_irq,
+};
+
+
/*
* Temporary debugging check.
*/
@@ -81,7 +109,6 @@
* -- wli
*/

-static void FASTCALL(__free_pages_ok (struct page *page, unsigned int order));
static void __free_pages_ok (struct page *page, unsigned int order)
{
unsigned long index, page_idx, mask, flags;
@@ -94,8 +121,20 @@
* a reference to a page in order to pin it for io. -ben
*/
if (PageLRU(page)) {
- if (unlikely(in_interrupt()))
- BUG();
+ if (unlikely(in_interrupt())) {
+ unsigned long flags;
+
+ spin_lock_irqsave(&free_pages_ok_no_irq_lock, flags);
+ page->next_hash = free_pages_ok_no_irq_head;
+ free_pages_ok_no_irq_head = page;
+ page->index = order;
+
+ spin_unlock_irqrestore(&free_pages_ok_no_irq_lock, flags);
+
+ schedule_task(&free_pages_ok_no_irq_task);
+ return;
+ }
+
lru_cache_del(page);
}