Re: [PATCH] kmalloc, kzalloc comments cleanup and fix

From: Randy.Dunlap
Date: Tue Jun 13 2006 - 00:27:47 EST


On Sat, 10 Jun 2006 23:39:42 +0400 Paul Drynoff wrote:

> It seems that previous patch was lost, so I resent patch,
> I also folded Randy Dunlap <rdunlap@xxxxxxxxxxxx>'s patch to make things more simple.

Acked-by: Randy Dunlap <rdunlap@xxxxxxxxxxxx>

Thanks. I was going to resend this to Andrew as well.
You just got to it before I did.

> Changes:
> 1)Move comments for kmalloc to right place, currently it near __do_kmalloc
> 2)Comments for kzalloc
> 3)More detailed comments for kmalloc
> 4)Appearance of "kmalloc" and "kzalloc" man pages after "make mandocs"
>
> Signed-off-by: Paul Drynoff <pauldrynoff@xxxxxxxxx>
>
> ---
>
> Index: linux-2.6.17-rc6-mm1/mm/slab.c
> ===================================================================
> --- linux-2.6.17-rc6-mm1.orig/mm/slab.c
> +++ linux-2.6.17-rc6-mm1/mm/slab.c
> @@ -3317,26 +3317,10 @@ EXPORT_SYMBOL(kmalloc_node);
> #endif
>
> /**
> - * kmalloc - allocate memory
> + * __do_kmalloc - allocate memory
> * @size: how many bytes of memory are required.
> - * @flags: the type of memory to allocate.
> + * @flags: the type of memory to allocate (see kmalloc).
> * @caller: function caller for debug tracking of the caller
> - *
> - * kmalloc is the normal method of allocating memory
> - * in the kernel.
> - *
> - * The @flags argument may be one of:
> - *
> - * %GFP_USER - Allocate memory on behalf of user. May sleep.
> - *
> - * %GFP_KERNEL - Allocate normal kernel ram. May sleep.
> - *
> - * %GFP_ATOMIC - Allocation will not sleep. Use inside interrupt handlers.
> - *
> - * Additionally, the %GFP_DMA flag may be set to indicate the memory
> - * must be suitable for DMA. This can mean different things on different
> - * platforms. For example, on i386, it means that the memory must come
> - * from the first 16MB.
> */
> static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
> void *caller)
> Index: linux-2.6.17-rc6-mm1/include/linux/slab.h
> ===================================================================
> --- linux-2.6.17-rc6-mm1.orig/include/linux/slab.h
> +++ linux-2.6.17-rc6-mm1/include/linux/slab.h
> @@ -86,6 +86,51 @@ extern void *__kmalloc_track_caller(size
> __kmalloc_track_caller(size, flags, __builtin_return_address(0))
> #endif
>
> +/**
> + * kmalloc - allocate memory
> + * @size: how many bytes of memory are required.
> + * @flags: the type of memory to allocate.
> + *
> + * kmalloc is the normal method of allocating memory
> + * in the kernel.
> + *
> + * The @flags argument may be one of:
> + *
> + * %GFP_USER - Allocate memory on behalf of user. May sleep.
> + *
> + * %GFP_KERNEL - Allocate normal kernel ram. May sleep.
> + *
> + * %GFP_ATOMIC - Allocation will not sleep.
> + * For example, use this inside interrupt handlers.
> + *
> + * %GFP_HIGHUSER - Allocate pages from high memory.
> + *
> + * %GFP_NOIO - Do not do any I/O at all while trying to get memory.
> + *
> + * %GFP_NOFS - Do not make any fs calls while trying to get memory.
> + *
> + * Also it is possible to set different flags by OR'ing
> + * in one or more of the following additional @flags:
> + *
> + * %__GFP_COLD - Request cache-cold pages instead of
> + * trying to return cache-warm pages.
> + *
> + * %__GFP_DMA - Request memory from the DMA-capable zone.
> + *
> + * %__GFP_HIGH - This allocation has high priority and may use emergency pools.
> + *
> + * %__GFP_HIGHMEM - Allocated memory may be from highmem.
> + *
> + * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail
> + * (think twice before using).
> + *
> + * %__GFP_NORETRY - If memory is not immediately available,
> + * then give up at once.
> + *
> + * %__GFP_NOWARN - If allocation fails, don't issue any warnings.
> + *
> + * %__GFP_REPEAT - If allocation fails initially, try once more before failing.
> + */
> static inline void *kmalloc(size_t size, gfp_t flags)
> {
> if (__builtin_constant_p(size)) {
> @@ -111,6 +156,11 @@ found:
>
> extern void *__kzalloc(size_t, gfp_t);
>
> +/**
> + * kzalloc - allocate memory. The memory is set to zero.
> + * @size: how many bytes of memory are required.
> + * @flags: the type of memory to allocate (see kmalloc).
> + */
> static inline void *kzalloc(size_t size, gfp_t flags)
> {
> if (__builtin_constant_p(size)) {
> Index: linux-2.6.17-rc6-mm1/Documentation/DocBook/kernel-api.tmpl
> ===================================================================
> --- linux-2.6.17-rc6-mm1.orig/Documentation/DocBook/kernel-api.tmpl
> +++ linux-2.6.17-rc6-mm1/Documentation/DocBook/kernel-api.tmpl
> @@ -117,6 +117,7 @@ X!Ilib/string.c
> <chapter id="mm">
> <title>Memory Management in Linux</title>
> <sect1><title>The Slab Cache</title>
> +!Iinclude/linux/slab.h
> !Emm/slab.c
> </sect1>
> <sect1><title>User Space Memory Access</title>
> -

---
~Randy
-
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