https://github.com/torvalds/linux
Revision e8a03feb54ca7f1768bbdc2b491f9ef654e6d01d authored by Rik van Riel on 14 April 2010, 21:59:28 UTC, committed by Linus Torvalds on 19 April 2010, 23:28:20 UTC
The recent anon_vma fixes cause many anonymous pages to end up in the parent process anon_vma, even when the page is exclusively owned by the current process. Adding exclusively owned anonymous pages to the top anon_vma reduces rmap scanning overhead, especially in workloads with forking servers. This patch adds a parameter to __page_set_anon_rmap that can be used to indicate whether or not the added page is exclusively owned by the current process. Pages added through page_add_new_anon_rmap are exclusively owned by the current process, and can be added to the top anon_vma. Pages added through page_add_anon_rmap can be either shared or exclusively owned, so we do the conservative thing and add it to the oldest anon_vma. A next step would be to add the exclusive parameter to page_add_anon_rmap, to be used from functions where we do know for sure whether a page is exclusively owned. Signed-off-by: Rik van Riel <riel@redhat.com> Reviewed-by: Johannes Weiner <hannes@cmpxchg.org> Lightly-tested-by: Borislav Petkov <bp@alien8.de> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> [ Edited to look nicer - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 9b030e2
Tip revision: e8a03feb54ca7f1768bbdc2b491f9ef654e6d01d authored by Rik van Riel on 14 April 2010, 21:59:28 UTC
rmap: add exclusively owned pages to the newest anon_vma
rmap: add exclusively owned pages to the newest anon_vma
Tip revision: e8a03fe
nfsctl.c
/*
* fs/nfsctl.c
*
* This should eventually move to userland.
*
*/
#include <linux/types.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/nfsd/syscall.h>
#include <linux/cred.h>
#include <linux/sched.h>
#include <linux/linkage.h>
#include <linux/namei.h>
#include <linux/mount.h>
#include <linux/syscalls.h>
#include <asm/uaccess.h>
/*
* open a file on nfsd fs
*/
static struct file *do_open(char *name, int flags)
{
struct nameidata nd;
struct vfsmount *mnt;
int error;
mnt = do_kern_mount("nfsd", 0, "nfsd", NULL);
if (IS_ERR(mnt))
return (struct file *)mnt;
error = vfs_path_lookup(mnt->mnt_root, mnt, name, 0, &nd);
mntput(mnt); /* drop do_kern_mount reference */
if (error)
return ERR_PTR(error);
if (flags == O_RDWR)
error = may_open(&nd.path, MAY_READ|MAY_WRITE, flags);
else
error = may_open(&nd.path, MAY_WRITE, flags);
if (!error)
return dentry_open(nd.path.dentry, nd.path.mnt, flags,
current_cred());
path_put(&nd.path);
return ERR_PTR(error);
}
static struct {
char *name; int wsize; int rsize;
} map[] = {
[NFSCTL_SVC] = {
.name = ".svc",
.wsize = sizeof(struct nfsctl_svc)
},
[NFSCTL_ADDCLIENT] = {
.name = ".add",
.wsize = sizeof(struct nfsctl_client)
},
[NFSCTL_DELCLIENT] = {
.name = ".del",
.wsize = sizeof(struct nfsctl_client)
},
[NFSCTL_EXPORT] = {
.name = ".export",
.wsize = sizeof(struct nfsctl_export)
},
[NFSCTL_UNEXPORT] = {
.name = ".unexport",
.wsize = sizeof(struct nfsctl_export)
},
[NFSCTL_GETFD] = {
.name = ".getfd",
.wsize = sizeof(struct nfsctl_fdparm),
.rsize = NFS_FHSIZE
},
[NFSCTL_GETFS] = {
.name = ".getfs",
.wsize = sizeof(struct nfsctl_fsparm),
.rsize = sizeof(struct knfsd_fh)
},
};
SYSCALL_DEFINE3(nfsservctl, int, cmd, struct nfsctl_arg __user *, arg,
void __user *, res)
{
struct file *file;
void __user *p = &arg->u;
int version;
int err;
if (copy_from_user(&version, &arg->ca_version, sizeof(int)))
return -EFAULT;
if (version != NFSCTL_VERSION)
return -EINVAL;
if (cmd < 0 || cmd >= ARRAY_SIZE(map) || !map[cmd].name)
return -EINVAL;
file = do_open(map[cmd].name, map[cmd].rsize ? O_RDWR : O_WRONLY);
if (IS_ERR(file))
return PTR_ERR(file);
err = file->f_op->write(file, p, map[cmd].wsize, &file->f_pos);
if (err >= 0 && map[cmd].rsize)
err = file->f_op->read(file, res, map[cmd].rsize, &file->f_pos);
if (err >= 0)
err = 0;
fput(file);
return err;
}
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