relayfs: support larger relay buffer
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>
diff --git a/kernel/relay.c b/kernel/relay.c
index d6204a4..bc24dcd 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -65,6 +65,35 @@
.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
* @buf: relay channel buffer
@@ -109,7 +138,7 @@
*size = PAGE_ALIGN(*size);
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)
return NULL;
@@ -130,7 +159,7 @@
depopulate:
for (j = 0; j < i; j++)
__free_page(buf->page_array[j]);
- kfree(buf->page_array);
+ relay_free_page_array(buf->page_array);
return NULL;
}
@@ -189,7 +218,7 @@
vunmap(buf->start);
for (i = 0; i < buf->page_count; i++)
__free_page(buf->page_array[i]);
- kfree(buf->page_array);
+ relay_free_page_array(buf->page_array);
}
chan->buf[buf->cpu] = NULL;
kfree(buf->padding);