* [PATCH 2/3] mm/slob: Use object_size field in kmem_cache_size()
2012-10-18 22:41 [PATCH 1/3] mm/slob: Drop usage of page->private for storing page-sized allocations Ezequiel Garcia
@ 2012-10-18 22:41 ` Ezequiel Garcia
2012-10-18 22:50 ` David Rientjes
2012-10-18 22:41 ` [PATCH 3/3] mm/sl[aou]b: Move common kmem_cache_size() to slab.h Ezequiel Garcia
` (2 subsequent siblings)
3 siblings, 1 reply; 7+ messages in thread
From: Ezequiel Garcia @ 2012-10-18 22:41 UTC (permalink / raw)
To: linux-mm, linux-kernel
Cc: Tim Bird, Ezequiel Garcia, Christoph Lameter, Pekka Enberg,
Matt Mackall
Fields object_size and size are not the same: the latter might include
slab metadata. Return object_size field in kmem_cache_size().
Also, improve trace accuracy by correctly tracing reported size.
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Ezequiel Garcia <elezegarcia@gmail.com>
---
mm/slob.c | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/mm/slob.c b/mm/slob.c
index 06a5ec7..287a88a 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -554,12 +554,12 @@ void *kmem_cache_alloc_node(struct kmem_cache *c, gfp_t flags, int node)
if (c->size < PAGE_SIZE) {
b = slob_alloc(c->size, flags, c->align, node);
- trace_kmem_cache_alloc_node(_RET_IP_, b, c->size,
+ trace_kmem_cache_alloc_node(_RET_IP_, b, c->object_size,
SLOB_UNITS(c->size) * SLOB_UNIT,
flags, node);
} else {
b = slob_new_pages(flags, get_order(c->size), node);
- trace_kmem_cache_alloc_node(_RET_IP_, b, c->size,
+ trace_kmem_cache_alloc_node(_RET_IP_, b, c->object_size,
PAGE_SIZE << get_order(c->size),
flags, node);
}
@@ -606,7 +606,7 @@ EXPORT_SYMBOL(kmem_cache_free);
unsigned int kmem_cache_size(struct kmem_cache *c)
{
- return c->size;
+ return c->object_size;
}
EXPORT_SYMBOL(kmem_cache_size);
--
1.7.8.6
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^ permalink raw reply related [flat|nested] 7+ messages in thread* Re: [PATCH 2/3] mm/slob: Use object_size field in kmem_cache_size()
2012-10-18 22:41 ` [PATCH 2/3] mm/slob: Use object_size field in kmem_cache_size() Ezequiel Garcia
@ 2012-10-18 22:50 ` David Rientjes
0 siblings, 0 replies; 7+ messages in thread
From: David Rientjes @ 2012-10-18 22:50 UTC (permalink / raw)
To: Ezequiel Garcia
Cc: linux-mm, linux-kernel, Tim Bird, Christoph Lameter, Pekka Enberg,
Matt Mackall
On Thu, 18 Oct 2012, Ezequiel Garcia wrote:
> Fields object_size and size are not the same: the latter might include
> slab metadata. Return object_size field in kmem_cache_size().
> Also, improve trace accuracy by correctly tracing reported size.
>
> Cc: Christoph Lameter <cl@linux-foundation.org>
> Cc: Pekka Enberg <penberg@kernel.org>
> Cc: Matt Mackall <mpm@selenic.com>
> Signed-off-by: Ezequiel Garcia <elezegarcia@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
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^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH 3/3] mm/sl[aou]b: Move common kmem_cache_size() to slab.h
2012-10-18 22:41 [PATCH 1/3] mm/slob: Drop usage of page->private for storing page-sized allocations Ezequiel Garcia
2012-10-18 22:41 ` [PATCH 2/3] mm/slob: Use object_size field in kmem_cache_size() Ezequiel Garcia
@ 2012-10-18 22:41 ` Ezequiel Garcia
2012-10-18 22:46 ` [PATCH 1/3] mm/slob: Drop usage of page->private for storing page-sized allocations David Rientjes
2012-10-31 6:56 ` Pekka Enberg
3 siblings, 0 replies; 7+ messages in thread
From: Ezequiel Garcia @ 2012-10-18 22:41 UTC (permalink / raw)
To: linux-mm, linux-kernel
Cc: Tim Bird, Ezequiel Garcia, Christoph Lameter, Pekka Enberg,
Matt Mackall
This function is identically defined in all three allocators
and it's trivial to move it to slab.h
Since now it's static, inline, header-defined function
this patch also drops the EXPORT_SYMBOL tag.
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Ezequiel Garcia <elezegarcia@gmail.com>
---
include/linux/slab.h | 9 ++++++++-
mm/slab.c | 6 ------
mm/slob.c | 6 ------
mm/slub.c | 9 ---------
4 files changed, 8 insertions(+), 22 deletions(-)
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 83d1a14..d513147 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -128,7 +128,6 @@ struct kmem_cache *kmem_cache_create(const char *, size_t, size_t,
void kmem_cache_destroy(struct kmem_cache *);
int kmem_cache_shrink(struct kmem_cache *);
void kmem_cache_free(struct kmem_cache *, void *);
-unsigned int kmem_cache_size(struct kmem_cache *);
/*
* Please use this macro to create slab caches. Simply specify the
@@ -388,6 +387,14 @@ static inline void *kzalloc_node(size_t size, gfp_t flags, int node)
return kmalloc_node(size, flags | __GFP_ZERO, node);
}
+/*
+ * Determine the size of a slab object
+ */
+unsigned int kmem_cache_size(struct kmem_cache *s)
+{
+ return s->object_size;
+}
+
void __init kmem_cache_init_late(void);
#endif /* _LINUX_SLAB_H */
diff --git a/mm/slab.c b/mm/slab.c
index 87c55b0..92a3fec 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3969,12 +3969,6 @@ void kfree(const void *objp)
}
EXPORT_SYMBOL(kfree);
-unsigned int kmem_cache_size(struct kmem_cache *cachep)
-{
- return cachep->object_size;
-}
-EXPORT_SYMBOL(kmem_cache_size);
-
/*
* This initializes kmem_list3 or resizes various caches for all nodes.
*/
diff --git a/mm/slob.c b/mm/slob.c
index 287a88a..fffbc82 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -604,12 +604,6 @@ void kmem_cache_free(struct kmem_cache *c, void *b)
}
EXPORT_SYMBOL(kmem_cache_free);
-unsigned int kmem_cache_size(struct kmem_cache *c)
-{
- return c->object_size;
-}
-EXPORT_SYMBOL(kmem_cache_size);
-
int __kmem_cache_shutdown(struct kmem_cache *c)
{
/* No way to check for remaining objects */
diff --git a/mm/slub.c b/mm/slub.c
index a0d6984..1f826b0 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -3127,15 +3127,6 @@ error:
return -EINVAL;
}
-/*
- * Determine the size of a slab object
- */
-unsigned int kmem_cache_size(struct kmem_cache *s)
-{
- return s->object_size;
-}
-EXPORT_SYMBOL(kmem_cache_size);
-
static void list_slab_objects(struct kmem_cache *s, struct page *page,
const char *text)
{
--
1.7.8.6
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^ permalink raw reply related [flat|nested] 7+ messages in thread* Re: [PATCH 1/3] mm/slob: Drop usage of page->private for storing page-sized allocations
2012-10-18 22:41 [PATCH 1/3] mm/slob: Drop usage of page->private for storing page-sized allocations Ezequiel Garcia
2012-10-18 22:41 ` [PATCH 2/3] mm/slob: Use object_size field in kmem_cache_size() Ezequiel Garcia
2012-10-18 22:41 ` [PATCH 3/3] mm/sl[aou]b: Move common kmem_cache_size() to slab.h Ezequiel Garcia
@ 2012-10-18 22:46 ` David Rientjes
2012-10-19 12:31 ` Ezequiel Garcia
2012-10-31 6:56 ` Pekka Enberg
3 siblings, 1 reply; 7+ messages in thread
From: David Rientjes @ 2012-10-18 22:46 UTC (permalink / raw)
To: Ezequiel Garcia
Cc: linux-mm, linux-kernel, Tim Bird, Pekka Enberg, Matt Mackall
On Thu, 18 Oct 2012, Ezequiel Garcia wrote:
> This field was being used to store size allocation so it could be
> retrieved by ksize(). However, it is a bad practice to not mark a page
> as a slab page and then use fields for special purposes.
> There is no need to store the allocated size and
> ksize() can simply return PAGE_SIZE << compound_order(page).
>
> Cc: Pekka Penberg <penberg@kernel.org>
Is Pekka Penberg the long distant cousin of Pekka Enberg? :) You should
probably cc the author of slob, Matt Mackall <mpm@selenic.com>, on slob
patches.
> Acked-by: Christoph Lameter <cl@linux.com>
> Signed-off-by: Ezequiel Garcia <elezegarcia@gmail.com>
> ---
> mm/slob.c | 24 ++++++++++--------------
> 1 files changed, 10 insertions(+), 14 deletions(-)
>
> diff --git a/mm/slob.c b/mm/slob.c
> index a08e468..06a5ec7 100644
> --- a/mm/slob.c
> +++ b/mm/slob.c
> @@ -28,9 +28,8 @@
> * from kmalloc are prepended with a 4-byte header with the kmalloc size.
> * If kmalloc is asked for objects of PAGE_SIZE or larger, it calls
> * alloc_pages() directly, allocating compound pages so the page order
> - * does not have to be separately tracked, and also stores the exact
> - * allocation size in page->private so that it can be used to accurately
> - * provide ksize(). These objects are detected in kfree() because slob_page()
> + * does not have to be separately tracked.
> + * These objects are detected in kfree() because PageSlab()
> * is false for them.
> *
> * SLAB is emulated on top of SLOB by simply calling constructors and
> @@ -455,11 +454,6 @@ __do_kmalloc_node(size_t size, gfp_t gfp, int node, unsigned long caller)
> if (likely(order))
> gfp |= __GFP_COMP;
> ret = slob_new_pages(gfp, order, node);
> - if (ret) {
> - struct page *page;
> - page = virt_to_page(ret);
> - page->private = size;
> - }
>
> trace_kmalloc_node(caller, ret,
> size, PAGE_SIZE << order, gfp, node);
> @@ -514,18 +508,20 @@ EXPORT_SYMBOL(kfree);
> size_t ksize(const void *block)
> {
> struct page *sp;
> + int align;
> + unsigned int *m;
>
> BUG_ON(!block);
> if (unlikely(block == ZERO_SIZE_PTR))
> return 0;
>
> sp = virt_to_page(block);
> - if (PageSlab(sp)) {
> - int align = max(ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN);
> - unsigned int *m = (unsigned int *)(block - align);
> - return SLOB_UNITS(*m) * SLOB_UNIT;
> - } else
> - return sp->private;
> + if (unlikely(!PageSlab(sp)))
> + return PAGE_SIZE << compound_order(sp);
> +
> + align = max(ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN);
> + m = (unsigned int *)(block - align);
> + return SLOB_UNITS(*m) * SLOB_UNIT;
> }
> EXPORT_SYMBOL(ksize);
>
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^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH 1/3] mm/slob: Drop usage of page->private for storing page-sized allocations
2012-10-18 22:46 ` [PATCH 1/3] mm/slob: Drop usage of page->private for storing page-sized allocations David Rientjes
@ 2012-10-19 12:31 ` Ezequiel Garcia
0 siblings, 0 replies; 7+ messages in thread
From: Ezequiel Garcia @ 2012-10-19 12:31 UTC (permalink / raw)
To: David Rientjes
Cc: linux-mm, linux-kernel, Tim Bird, Pekka Enberg, Matt Mackall
On Thu, Oct 18, 2012 at 7:46 PM, David Rientjes <rientjes@google.com> wrote:
> On Thu, 18 Oct 2012, Ezequiel Garcia wrote:
>
>> This field was being used to store size allocation so it could be
>> retrieved by ksize(). However, it is a bad practice to not mark a page
>> as a slab page and then use fields for special purposes.
>> There is no need to store the allocated size and
>> ksize() can simply return PAGE_SIZE << compound_order(page).
>>
>> Cc: Pekka Penberg <penberg@kernel.org>
>
> Is Pekka Penberg the long distant cousin of Pekka Enberg? :) You should
> probably cc the author of slob, Matt Mackall <mpm@selenic.com>, on slob
> patches.
>
Ouch! ;-)
I found another typo so I'll just re-send the whole patchset.
Thanks for the review!
Ezequiel
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^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH 1/3] mm/slob: Drop usage of page->private for storing page-sized allocations
2012-10-18 22:41 [PATCH 1/3] mm/slob: Drop usage of page->private for storing page-sized allocations Ezequiel Garcia
` (2 preceding siblings ...)
2012-10-18 22:46 ` [PATCH 1/3] mm/slob: Drop usage of page->private for storing page-sized allocations David Rientjes
@ 2012-10-31 6:56 ` Pekka Enberg
3 siblings, 0 replies; 7+ messages in thread
From: Pekka Enberg @ 2012-10-31 6:56 UTC (permalink / raw)
To: Ezequiel Garcia; +Cc: linux-mm, linux-kernel, Tim Bird
On Fri, Oct 19, 2012 at 1:41 AM, Ezequiel Garcia <elezegarcia@gmail.com> wrote:
> This field was being used to store size allocation so it could be
> retrieved by ksize(). However, it is a bad practice to not mark a page
> as a slab page and then use fields for special purposes.
> There is no need to store the allocated size and
> ksize() can simply return PAGE_SIZE << compound_order(page).
>
> Cc: Pekka Penberg <penberg@kernel.org>
> Acked-by: Christoph Lameter <cl@linux.com>
> Signed-off-by: Ezequiel Garcia <elezegarcia@gmail.com>
Applied all three patches. Thanks, Ezequiel!
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^ permalink raw reply [flat|nested] 7+ messages in thread