slab: introduce krealloc
This introduce krealloc() that reallocates memory while keeping the contents unchanged. The allocator avoids reallocation if the new size fits the currently used cache. I also added a simple non-optimized version for mm/slob.c for compatibility. [akpm@linux-foundation.org: fix warnings] Acked-by: Josef Sipek <jsipek@fsl.cs.sunysb.edu> Acked-by: Matt Mackall <mpm@selenic.com> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
committed by
Linus Torvalds
parent
e3ebadd95c
commit
fd76bab2fa
35
mm/slob.c
35
mm/slob.c
@@ -190,6 +190,39 @@ void *__kmalloc(size_t size, gfp_t gfp)
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}
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EXPORT_SYMBOL(__kmalloc);
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/**
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* krealloc - reallocate memory. The contents will remain unchanged.
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*
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* @p: object to reallocate memory for.
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* @new_size: how many bytes of memory are required.
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* @flags: the type of memory to allocate.
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*
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* The contents of the object pointed to are preserved up to the
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* lesser of the new and old sizes. If @p is %NULL, krealloc()
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* behaves exactly like kmalloc(). If @size is 0 and @p is not a
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* %NULL pointer, the object pointed to is freed.
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*/
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void *krealloc(const void *p, size_t new_size, gfp_t flags)
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{
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void *ret;
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if (unlikely(!p))
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return kmalloc_track_caller(new_size, flags);
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if (unlikely(!new_size)) {
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kfree(p);
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return NULL;
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}
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ret = kmalloc_track_caller(new_size, flags);
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if (ret) {
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memcpy(ret, p, min(new_size, ksize(p)));
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kfree(p);
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}
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return ret;
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}
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EXPORT_SYMBOL(krealloc);
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void kfree(const void *block)
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{
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bigblock_t *bb, **last = &bigblocks;
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@@ -219,7 +252,7 @@ void kfree(const void *block)
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EXPORT_SYMBOL(kfree);
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unsigned int ksize(const void *block)
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size_t ksize(const void *block)
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{
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bigblock_t *bb;
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unsigned long flags;
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