Re: %u-order allocation failed

[Rik van Riel <riel@xxxxxxxxxxxxxxxx>]

On Sat, 6 Oct 2001, Mikulas Patocka wrote:
> On Sat, 6 Oct 2001, Rik van Riel wrote:
> > On Sat, 6 Oct 2001, Mikulas Patocka wrote:
> >
> > > Buddy allocator is broken - kill it. Or at least do not misuse it for
> > > anything except kernel or driver initialization.
> >
> > Please send patches to get rid of the buddy allocator while
> > still making it possible to allocate contiguous chunks of
> > memory.
> >
> > If you have any idea on how to fix things, this would be a
> > good time to let us know.
>
> Here goes the fix. (note that I didn't try to compile it so there may be
> bugs, but you see the point).

So what are you going to do when your 64MB of vmalloc space
runs out ?

Rik
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diff -u -r linux-orig/include/asm-i386/processor.h 
linux/include/asm-i386/processor.h
--- linux-orig/include/asm-i386/processor.h     Sat Oct  6 16:21:50 2001
+++ linux/include/asm-i386/processor.h  Sat Oct  6 16:31:15 2001
@@ -448,7 +448,7 @@
 #define KSTK_ESP(tsk)  (((unsigned long *)(4096+(unsigned long)(tsk)))[1022])
 
 #define THREAD_SIZE (2*PAGE_SIZE)
-#define alloc_task_struct() ((struct task_struct *) 
__get_free_pages(GFP_KERNEL,1))
+#define alloc_task_struct() ((struct task_struct *) 
__get_free_pages(GFP_KERNEL | __GFP_VMALLOC,1))
 #define free_task_struct(p) free_pages((unsigned long) (p), 1)
 #define get_task_struct(tsk)      atomic_inc(&virt_to_page(tsk)->count)
 
diff -u -r linux-orig/include/linux/mm.h linux/include/linux/mm.h
--- linux-orig/include/linux/mm.h       Sat Oct  6 16:21:59 2001
+++ linux/include/linux/mm.h    Sat Oct  6 16:28:12 2001
@@ -550,6 +550,7 @@
 #define __GFP_IO       0x40    /* Can start low memory physical IO? */
 #define __GFP_HIGHIO   0x80    /* Can start high mem physical IO? */
 #define __GFP_FS       0x100   /* Can call down to low-level FS? */
+#define __GFP_VMALLOC  0x200   /* Can vmalloc pages if buddy allocator fails */
 
 #define GFP_NOHIGHIO   (__GFP_HIGH | __GFP_WAIT | __GFP_IO)
 #define GFP_NOIO       (__GFP_HIGH | __GFP_WAIT)
diff -u -r linux-orig/mm/page_alloc.c linux/mm/page_alloc.c
--- linux-orig/mm/page_alloc.c  Sat Oct  6 16:21:47 2001
+++ linux/mm/page_alloc.c       Sat Oct  6 16:36:28 2001
@@ -18,6 +18,7 @@
 #include <linux/bootmem.h>
 #include <linux/slab.h>
 #include <linux/compiler.h>
+#include <linux/vmalloc.h>
 
 int nr_swap_pages;
 int nr_active_pages;
@@ -421,9 +422,9 @@
        struct page * page;
 
        page = alloc_pages(gfp_mask, order);
-       if (!page)
-               return 0;
-       return (unsigned long) page_address(page);
+       if (page) return (unsigned long) page_address(page);
+       if (gfp_mask & __GFP_VMALLOC) return (unsigned long)__vmalloc(PAGE_SIZE 
<< order, gfp_mask, PAGE_KERNEL);
+       return 0;
 }
 
 unsigned long get_zeroed_page(unsigned int gfp_mask)
@@ -447,6 +448,10 @@
 
 void free_pages(unsigned long addr, unsigned int order)
 {
+       if (addr >= VMALLOC_START && addr < VMALLOC_END) {
+               vfree((void *)addr);
+               return;
+       }
        if (addr != 0)
                __free_pages(virt_to_page(addr), order);
 }