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: Pekka Enberg <penberg@cs.helsinki.fi>

4 files changed, 12 insertions, 0 deletions

diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 0bbc15f54536..3760e7c5de02 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -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)
 
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 48803064cedf..219b8fb4651d 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -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 */
diff --git a/include/linux/slob_def.h b/include/linux/slob_def.h
index 0ec00b39d006..bb5368df4be8 100644
--- a/include/linux/slob_def.h
+++ b/include/linux/slob_def.h
@@ -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 */
diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index be5d40c43bd2..4dcbc2c71491 100644
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -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 */