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Commit a0358cea authored by Trond Myklebust's avatar Trond Myklebust
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Subject: [PATCH] NFS: Direct write path allocates nfs_write_data on the stack 

 Reduce stack utilization in the NFS direct write path by using a
 dynamically allocated nfs_write_data structure instead of allocating one
 on the stack.  This reduces stack utilization of nfs_direct_write_seg
 from over 900 bytes to less than 100 bytes.
Signed-off-by: default avatarChuck Lever <cel@netapp.com>
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@fys.uio.no>
parent 1f02f151
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Inline Side-by-side
Showing with 79 additions and 74 deletions
fs/nfs/direct.c
View file @ a0358cea
......@@ -255,22 +255,21 @@ nfs_direct_write_seg(struct inode *inode, struct nfs_open_context *ctx,
size_t request;
int curpage, need_commit, result, tot_bytes;
struct nfs_writeverf first_verf;
struct nfs_write_data wdata = {
.inode = inode,
.cred = ctx->cred,
.args = {
.fh = NFS_FH(inode),
.context = ctx,
},
.res = {
.fattr = &wdata.fattr,
.verf = &wdata.verf,
},
};
struct nfs_write_data *wdata;
wdata.args.stable = NFS_UNSTABLE;
wdata = nfs_writedata_alloc();
if (!wdata)
return -ENOMEM;
wdata->inode = inode;
wdata->cred = ctx->cred;
wdata->args.fh = NFS_FH(inode);
wdata->args.context = ctx;
wdata->args.stable = NFS_UNSTABLE;
if (IS_SYNC(inode) || NFS_PROTO(inode)->version == 2 || count <= wsize)
wdata.args.stable = NFS_FILE_SYNC;
wdata->args.stable = NFS_FILE_SYNC;
wdata->res.fattr = &wdata->fattr;
wdata->res.verf = &wdata->verf;
nfs_begin_data_update(inode);
retry:
......@@ -278,20 +277,20 @@ nfs_direct_write_seg(struct inode *inode, struct nfs_open_context *ctx,
tot_bytes = 0;
curpage = 0;
request = count;
wdata.args.pgbase = user_addr & ~PAGE_MASK;
wdata.args.offset = file_offset;
do {
wdata.args.count = request;
if (wdata.args.count > wsize)
wdata.args.count = wsize;
wdata.args.pages = &pages[curpage];
wdata->args.pgbase = user_addr & ~PAGE_MASK;
wdata->args.offset = file_offset;
do {
wdata->args.count = request;
if (wdata->args.count > wsize)
wdata->args.count = wsize;
wdata->args.pages = &pages[curpage];
dprintk("NFS: direct write: c=%u o=%Ld ua=%lu, pb=%u, cp=%u\n",
wdata.args.count, (long long) wdata.args.offset,
user_addr + tot_bytes, wdata.args.pgbase, curpage);
wdata->args.count, (long long) wdata->args.offset,
user_addr + tot_bytes, wdata->args.pgbase, curpage);
lock_kernel();
result = NFS_PROTO(inode)->write(&wdata);
result = NFS_PROTO(inode)->write(wdata);
unlock_kernel();
if (result <= 0) {
......@@ -301,11 +300,11 @@ nfs_direct_write_seg(struct inode *inode, struct nfs_open_context *ctx,
}
if (tot_bytes == 0)
memcpy(&first_verf.verifier, &wdata.verf.verifier,
memcpy(&first_verf.verifier, &wdata->verf.verifier,
sizeof(first_verf.verifier));
if (wdata.verf.committed != NFS_FILE_SYNC) {
if (wdata->verf.committed != NFS_FILE_SYNC) {
need_commit = 1;
if (memcmp(&first_verf.verifier, &wdata.verf.verifier,
if (memcmp(&first_verf.verifier, &wdata->verf.verifier,
sizeof(first_verf.verifier)));
goto sync_retry;
}
......@@ -313,13 +312,13 @@ nfs_direct_write_seg(struct inode *inode, struct nfs_open_context *ctx,
tot_bytes += result;
/* in case of a short write: stop now, let the app recover */
if (result < wdata.args.count)
if (result < wdata->args.count)
break;
wdata.args.offset += result;
wdata.args.pgbase += result;
curpage += wdata.args.pgbase >> PAGE_SHIFT;
wdata.args.pgbase &= ~PAGE_MASK;
wdata->args.offset += result;
wdata->args.pgbase += result;
curpage += wdata->args.pgbase >> PAGE_SHIFT;
wdata->args.pgbase &= ~PAGE_MASK;
request -= result;
} while (request != 0);
......@@ -327,15 +326,15 @@ nfs_direct_write_seg(struct inode *inode, struct nfs_open_context *ctx,
* Commit data written so far, even in the event of an error
*/
if (need_commit) {
wdata.args.count = tot_bytes;
wdata.args.offset = file_offset;
wdata->args.count = tot_bytes;
wdata->args.offset = file_offset;
lock_kernel();
result = NFS_PROTO(inode)->commit(&wdata);
result = NFS_PROTO(inode)->commit(wdata);
unlock_kernel();
if (result < 0 || memcmp(&first_verf.verifier,
&wdata.verf.verifier,
&wdata->verf.verifier,
sizeof(first_verf.verifier)) != 0)
goto sync_retry;
}
......@@ -343,11 +342,11 @@ nfs_direct_write_seg(struct inode *inode, struct nfs_open_context *ctx,
out:
nfs_end_data_update_defer(inode);
nfs_writedata_free(wdata);
return result;
sync_retry:
wdata.args.stable = NFS_FILE_SYNC;
wdata->args.stable = NFS_FILE_SYNC;
goto retry;
}
......
fs/nfs/write.c
View file @ a0358cea
......@@ -61,7 +61,6 @@
#include <linux/nfs_page.h>
#include <asm/uaccess.h>
#include <linux/smp_lock.h>
#include <linux/mempool.h>
#include "delegation.h"
......@@ -83,49 +82,17 @@ static int nfs_wait_on_write_congestion(struct address_space *, int);
static int nfs_wait_on_requests(struct inode *, unsigned long, unsigned int);
static kmem_cache_t *nfs_wdata_cachep;
static mempool_t *nfs_wdata_mempool;
static mempool_t *nfs_commit_mempool;
mempool_t *nfs_wdata_mempool;
mempool_t *nfs_commit_mempool;
static DECLARE_WAIT_QUEUE_HEAD(nfs_write_congestion);
static __inline__ struct nfs_write_data *nfs_writedata_alloc(void)
{
struct nfs_write_data *p;
p = (struct nfs_write_data *)mempool_alloc(nfs_wdata_mempool, SLAB_NOFS);
if (p) {
memset(p, 0, sizeof(*p));
INIT_LIST_HEAD(&p->pages);
}
return p;
}
static __inline__ void nfs_writedata_free(struct nfs_write_data *p)
{
mempool_free(p, nfs_wdata_mempool);
}
static void nfs_writedata_release(struct rpc_task *task)
void nfs_writedata_release(struct rpc_task *task)
{
struct nfs_write_data *wdata = (struct nfs_write_data *)task->tk_calldata;
nfs_writedata_free(wdata);
}
static __inline__ struct nfs_write_data *nfs_commit_alloc(void)
{
struct nfs_write_data *p;
p = (struct nfs_write_data *)mempool_alloc(nfs_commit_mempool, SLAB_NOFS);
if (p) {
memset(p, 0, sizeof(*p));
INIT_LIST_HEAD(&p->pages);
}
return p;
}
static __inline__ void nfs_commit_free(struct nfs_write_data *p)
{
mempool_free(p, nfs_commit_mempool);
}
/* Adjust the file length if we're writing beyond the end */
static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int count)
{
......
include/linux/nfs_fs.h
View file @ a0358cea
......@@ -30,6 +30,7 @@
#include <linux/nfs_xdr.h>
#include <linux/rwsem.h>
#include <linux/workqueue.h>
#include <linux/mempool.h>
/*
* Enable debugging support for nfs client.
......@@ -424,6 +425,44 @@ static inline int nfs_wb_page(struct inode *inode, struct page* page)
return nfs_wb_page_priority(inode, page, 0);
}
/*
* Allocate and free nfs_write_data structures
*/
extern mempool_t *nfs_wdata_mempool;
extern mempool_t *nfs_commit_mempool;
static inline struct nfs_write_data *nfs_writedata_alloc(void)
{
struct nfs_write_data *p = mempool_alloc(nfs_wdata_mempool, SLAB_NOFS);
if (p) {
memset(p, 0, sizeof(*p));
INIT_LIST_HEAD(&p->pages);
}
return p;
}
static inline void nfs_writedata_free(struct nfs_write_data *p)
{
mempool_free(p, nfs_wdata_mempool);
}
extern void nfs_writedata_release(struct rpc_task *task);
static inline struct nfs_write_data *nfs_commit_alloc(void)
{
struct nfs_write_data *p = mempool_alloc(nfs_commit_mempool, SLAB_NOFS);
if (p) {
memset(p, 0, sizeof(*p));
INIT_LIST_HEAD(&p->pages);
}
return p;
}
static inline void nfs_commit_free(struct nfs_write_data *p)
{
mempool_free(p, nfs_commit_mempool);
}
/* Hack for future NFS swap support */
#ifndef IS_SWAPFILE
# define IS_SWAPFILE(inode) (0)
......
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