Messages in this thread Patch in this message | | | Date | Wed, 3 Nov 1999 16:58:22 +0100 (CET) | From | Andrea Arcangeli <> | Subject | [patch] bigmem fix for random out of memory (for 2.3.25) |
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Leonard spotted a bug in the bigmem initialization code. I couldn't debug it as it can't trigger with the bigmem emulation.
Actually GFP will return NULL if RMQUEUE grabbed the physical page at address -PAGE_OFFSET. Lenonard fixed this to just avoid to put the bigmem in the freelist and I would do the same too as one page is not a big deal with real bigmem hardware.
I merged his plain fix in my 2.2.13 bigmem and I reworked it for 2.3.25.
The other cleaner way to fix this bug is to change GFP to return a `struct page *' or the `pfn' and the other way is definitely not a one-liner ;). Even if we want to fix it properly in the other way we can go with this trick today (it will be trivial to remove the check later).
--- 2.3.25-i386/arch/i386/mm/init.c.~1~ Tue Oct 26 21:30:50 1999 +++ 2.3.25-i386/arch/i386/mm/init.c Wed Nov 3 16:52:30 1999 @@ -526,6 +526,12 @@ SetPageReserved(page); continue; } + /* GFP in page_alloc.c would return zero for the + bigmem page located at physical address -PAGE_OFFSET. + We cannot allow GFP to return 0 since the callers of + treat 0 as an allocation failure. */ + if (!((tmp << PAGE_SHIFT) + PAGE_OFFSET)) + continue; ClearPageReserved(page); set_bit(PG_highmem, &page->flags); atomic_set(&page->count, 1); Andrea
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