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relayfs: support larger relay buffer

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Use vmalloc() and memset() instead of kcalloc() to allocate a page* array when
the array size is bigger than one page.  This enables relayfs to support
bigger relay buffers than 64MB on 4k-page system, 512MB on 16k-page system.

[akpm@linux-foundation.org: cleanup]
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: David Wilder <dwilder@us.ibm.com>
Reviewed-by: Tom Zanussi <zanussi@comcast.net>
Reviewed-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:
Masami Hiramatsu 2008-04-29 01:03:46 -07:00 • committed by Linus Torvalds
parent 97a4feb4a7
commit 68ab3d883a
1 changed files with 32 additions and 3 deletions
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35
kernel/relay.c
View file

@ -65,6 +65,35 @@ static struct vm_operations_struct relay_file_mmap_ops = {
.close = relay_file_mmap_close, .close = relay_file_mmap_close,
}; };
/*
* allocate an array of pointers of struct page
*/
static struct page **relay_alloc_page_array(unsigned int n_pages)
{
struct page **array;
size_t pa_size = n_pages * sizeof(struct page *);
if (pa_size > PAGE_SIZE) {
array = vmalloc(pa_size);
if (array)
memset(array, 0, pa_size);
} else {
array = kzalloc(pa_size, GFP_KERNEL);
}
return array;
}
/*
* free an array of pointers of struct page
*/
static void relay_free_page_array(struct page **array)
{
if (is_vmalloc_addr(array))
vfree(array);
else
kfree(array);
}
/** /**
* relay_mmap_buf: - mmap channel buffer to process address space * relay_mmap_buf: - mmap channel buffer to process address space
* @buf: relay channel buffer * @buf: relay channel buffer
@ -109,7 +138,7 @@ static void *relay_alloc_buf(struct rchan_buf *buf, size_t *size)
*size = PAGE_ALIGN(*size); *size = PAGE_ALIGN(*size);
n_pages = *size >> PAGE_SHIFT; n_pages = *size >> PAGE_SHIFT;
buf->page_array = kcalloc(n_pages, sizeof(struct page *), GFP_KERNEL); buf->page_array = relay_alloc_page_array(n_pages);
if (!buf->page_array) if (!buf->page_array)
return NULL; return NULL;
@ -130,7 +159,7 @@ static void *relay_alloc_buf(struct rchan_buf *buf, size_t *size)
depopulate: depopulate:
for (j = 0; j < i; j++) for (j = 0; j < i; j++)
__free_page(buf->page_array[j]); __free_page(buf->page_array[j]);
kfree(buf->page_array); relay_free_page_array(buf->page_array);
return NULL; return NULL;
} }
@ -189,7 +218,7 @@ static void relay_destroy_buf(struct rchan_buf *buf)
vunmap(buf->start); vunmap(buf->start);
for (i = 0; i < buf->page_count; i++) for (i = 0; i < buf->page_count; i++)
__free_page(buf->page_array[i]); __free_page(buf->page_array[i]);
kfree(buf->page_array); relay_free_page_array(buf->page_array);
} }
chan->buf[buf->cpu] = NULL; chan->buf[buf->cpu] = NULL;
kfree(buf->padding); kfree(buf->padding);