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Commit 7e85ee0c authored by Pekka Enberg's avatar Pekka Enberg
Browse files

slab,slub: don't enable interrupts during early boot 



As explained by Benjamin Herrenschmidt:

  Oh and btw, your patch alone doesn't fix powerpc, because it's missing
  a whole bunch of GFP_KERNEL's in the arch code... You would have to
  grep the entire kernel for things that check slab_is_available() and
  even then you'll be missing some.

  For example, slab_is_available() didn't always exist, and so in the
  early days on powerpc, we used a mem_init_done global that is set form
  mem_init() (not perfect but works in practice). And we still have code
  using that to do the test.

Therefore, mask out __GFP_WAIT, __GFP_IO, and __GFP_FS in the slab allocators
in early boot code to avoid enabling interrupts.

Signed-off-by: default avatarPekka Enberg <penberg@cs.helsinki.fi>
parent eb91f1d0

include/linux/gfp.h

+3 −0
Original line number Diff line number Diff line
@@ -85,6 +85,9 @@ struct vm_area_struct; 
			__GFP_NOWARN|__GFP_REPEAT|__GFP_NOFAIL|\

			__GFP_NORETRY|__GFP_NOMEMALLOC)



/* Control slab gfp mask during early boot */

#define SLAB_GFP_BOOT_MASK __GFP_BITS_MASK & ~(__GFP_WAIT|__GFP_IO|__GFP_FS)



/* Control allocation constraints */

#define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)

include/linux/slab.h

+2 −0
Original line number Diff line number Diff line
@@ -319,4 +319,6 @@ static inline void *kzalloc_node(size_t size, gfp_t flags, int node) 
	return kmalloc_node(size, flags | __GFP_ZERO, node);

}



void __init kmem_cache_init_late(void);



#endif	/* _LINUX_SLAB_H */

include/linux/slob_def.h

+5 −0
Original line number Diff line number Diff line
@@ -34,4 +34,9 @@ static __always_inline void *__kmalloc(size_t size, gfp_t flags) 
	return kmalloc(size, flags);

}



static inline void kmem_cache_init_late(void)

{

	/* Nothing to do */

}



#endif /* __LINUX_SLOB_DEF_H */

include/linux/slub_def.h

+2 −0
Original line number Diff line number Diff line
@@ -302,4 +302,6 @@ static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node) 
}

#endif



void __init kmem_cache_init_late(void);



#endif /* _LINUX_SLUB_DEF_H */

init/main.c

+1 −0
Original line number Diff line number Diff line
@@ -640,6 +640,7 @@ asmlinkage void __init start_kernel(void) 
				 "enabled early\n");

	early_boot_irqs_on();

	local_irq_enable();

	kmem_cache_init_late();



	/*

	 * HACK ALERT! This is early. We're enabling the console before