NFS: Optimize allocation of nfs_read/write_data structures
Clean up use of page_array, and fix an off-by-one error noticed by Tom
Talpey which causes kmalloc calls in cases where using the page_array
is sufficient.
Test plan:
Normal client functional testing with r/wsize=32768.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 4cfada2..a515ec7 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -98,11 +98,10 @@
if (p) {
memset(p, 0, sizeof(*p));
INIT_LIST_HEAD(&p->pages);
- if (pagecount < NFS_PAGEVEC_SIZE)
- p->pagevec = &p->page_array[0];
+ if (pagecount <= ARRAY_SIZE(p->page_array))
+ p->pagevec = p->page_array;
else {
- size_t size = ++pagecount * sizeof(struct page *);
- p->pagevec = kzalloc(size, GFP_NOFS);
+ p->pagevec = kcalloc(pagecount, sizeof(struct page *), GFP_NOFS);
if (!p->pagevec) {
mempool_free(p, nfs_commit_mempool);
p = NULL;
@@ -126,14 +125,11 @@
if (p) {
memset(p, 0, sizeof(*p));
INIT_LIST_HEAD(&p->pages);
- if (pagecount < NFS_PAGEVEC_SIZE)
- p->pagevec = &p->page_array[0];
+ if (pagecount <= ARRAY_SIZE(p->page_array))
+ p->pagevec = p->page_array;
else {
- size_t size = ++pagecount * sizeof(struct page *);
- p->pagevec = kmalloc(size, GFP_NOFS);
- if (p->pagevec) {
- memset(p->pagevec, 0, size);
- } else {
+ p->pagevec = kcalloc(pagecount, sizeof(struct page *), GFP_NOFS);
+ if (!p->pagevec) {
mempool_free(p, nfs_wdata_mempool);
p = NULL;
}