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authorPaul Menage <menage@google.com>2008-07-25 01:47:02 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-25 10:53:36 -0700
commite37123953292146445c8629b3950d0513fd10ae2 (patch)
tree8481ef1898a61cb5438205df349e01c432a1d55b
parentaf351026aafc8da16518a02b41c66d3e0c1cdef4 (diff)
downloadlinux-2.6.38-lt-ux500-e37123953292146445c8629b3950d0513fd10ae2.tar.gz
cgroup files: remove cpuset_common_file_write()
This patch tweaks the signatures of the update_cpumask() and update_nodemask() functions so that they can be called directly as handlers for the new cgroups write_string() method. This allows cpuset_common_file_write() to be removed. Signed-off-by: Paul Menage <menage@google.com> Cc: Paul Jackson <pj@sgi.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Serge Hallyn <serue@us.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--kernel/cpuset.c109
1 files changed, 35 insertions, 74 deletions
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index d5738910c34..276ce7e4f1a 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -227,10 +227,6 @@ static struct cpuset top_cpuset = {
* The task_struct fields mems_allowed and mems_generation may only
* be accessed in the context of that task, so require no locks.
*
- * The cpuset_common_file_write handler for operations that modify
- * the cpuset hierarchy holds cgroup_mutex across the entire operation,
- * single threading all such cpuset modifications across the system.
- *
* The cpuset_common_file_read() handlers only hold callback_mutex across
* small pieces of code, such as when reading out possibly multi-word
* cpumasks and nodemasks.
@@ -772,7 +768,7 @@ static void cpuset_change_cpumask(struct task_struct *tsk,
* @cs: the cpuset to consider
* @buf: buffer of cpu numbers written to this cpuset
*/
-static int update_cpumask(struct cpuset *cs, char *buf)
+static int update_cpumask(struct cpuset *cs, const char *buf)
{
struct cpuset trialcs;
struct cgroup_scanner scan;
@@ -792,7 +788,6 @@ static int update_cpumask(struct cpuset *cs, char *buf)
* that parsing. The validate_change() call ensures that cpusets
* with tasks have cpus.
*/
- buf = strstrip(buf);
if (!*buf) {
cpus_clear(trialcs.cpus_allowed);
} else {
@@ -902,7 +897,7 @@ static void cpuset_migrate_mm(struct mm_struct *mm, const nodemask_t *from,
static void *cpuset_being_rebound;
-static int update_nodemask(struct cpuset *cs, char *buf)
+static int update_nodemask(struct cpuset *cs, const char *buf)
{
struct cpuset trialcs;
nodemask_t oldmem;
@@ -929,7 +924,6 @@ static int update_nodemask(struct cpuset *cs, char *buf)
* that parsing. The validate_change() call ensures that cpusets
* with tasks have memory.
*/
- buf = strstrip(buf);
if (!*buf) {
nodes_clear(trialcs.mems_allowed);
} else {
@@ -1256,72 +1250,14 @@ typedef enum {
FILE_SPREAD_SLAB,
} cpuset_filetype_t;
-static ssize_t cpuset_common_file_write(struct cgroup *cont,
- struct cftype *cft,
- struct file *file,
- const char __user *userbuf,
- size_t nbytes, loff_t *unused_ppos)
-{
- struct cpuset *cs = cgroup_cs(cont);
- cpuset_filetype_t type = cft->private;
- char *buffer;
- int retval = 0;
-
- /* Crude upper limit on largest legitimate cpulist user might write. */
- if (nbytes > 100U + 6 * max(NR_CPUS, MAX_NUMNODES))
- return -E2BIG;
-
- /* +1 for nul-terminator */
- buffer = kmalloc(nbytes + 1, GFP_KERNEL);
- if (!buffer)
- return -ENOMEM;
-
- if (copy_from_user(buffer, userbuf, nbytes)) {
- retval = -EFAULT;
- goto out1;
- }
- buffer[nbytes] = 0; /* nul-terminate */
-
- cgroup_lock();
-
- if (cgroup_is_removed(cont)) {
- retval = -ENODEV;
- goto out2;
- }
-
- switch (type) {
- case FILE_CPULIST:
- retval = update_cpumask(cs, buffer);
- break;
- case FILE_MEMLIST:
- retval = update_nodemask(cs, buffer);
- break;
- default:
- retval = -EINVAL;
- goto out2;
- }
-
- if (retval == 0)
- retval = nbytes;
-out2:
- cgroup_unlock();
-out1:
- kfree(buffer);
- return retval;
-}
-
static int cpuset_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val)
{
int retval = 0;
struct cpuset *cs = cgroup_cs(cgrp);
cpuset_filetype_t type = cft->private;
- cgroup_lock();
-
- if (cgroup_is_removed(cgrp)) {
- cgroup_unlock();
+ if (!cgroup_lock_live_group(cgrp))
return -ENODEV;
- }
switch (type) {
case FILE_CPU_EXCLUSIVE:
@@ -1367,12 +1303,9 @@ static int cpuset_write_s64(struct cgroup *cgrp, struct cftype *cft, s64 val)
struct cpuset *cs = cgroup_cs(cgrp);
cpuset_filetype_t type = cft->private;
- cgroup_lock();
-
- if (cgroup_is_removed(cgrp)) {
- cgroup_unlock();
+ if (!cgroup_lock_live_group(cgrp))
return -ENODEV;
- }
+
switch (type) {
case FILE_SCHED_RELAX_DOMAIN_LEVEL:
retval = update_relax_domain_level(cs, val);
@@ -1386,6 +1319,32 @@ static int cpuset_write_s64(struct cgroup *cgrp, struct cftype *cft, s64 val)
}
/*
+ * Common handling for a write to a "cpus" or "mems" file.
+ */
+static int cpuset_write_resmask(struct cgroup *cgrp, struct cftype *cft,
+ const char *buf)
+{
+ int retval = 0;
+
+ if (!cgroup_lock_live_group(cgrp))
+ return -ENODEV;
+
+ switch (cft->private) {
+ case FILE_CPULIST:
+ retval = update_cpumask(cgroup_cs(cgrp), buf);
+ break;
+ case FILE_MEMLIST:
+ retval = update_nodemask(cgroup_cs(cgrp), buf);
+ break;
+ default:
+ retval = -EINVAL;
+ break;
+ }
+ cgroup_unlock();
+ return retval;
+}
+
+/*
* These ascii lists should be read in a single call, by using a user
* buffer large enough to hold the entire map. If read in smaller
* chunks, there is no guarantee of atomicity. Since the display format
@@ -1504,14 +1463,16 @@ static struct cftype files[] = {
{
.name = "cpus",
.read = cpuset_common_file_read,
- .write = cpuset_common_file_write,
+ .write_string = cpuset_write_resmask,
+ .max_write_len = (100U + 6 * NR_CPUS),
.private = FILE_CPULIST,
},
{
.name = "mems",
.read = cpuset_common_file_read,
- .write = cpuset_common_file_write,
+ .write_string = cpuset_write_resmask,
+ .max_write_len = (100U + 6 * MAX_NUMNODES),
.private = FILE_MEMLIST,
},