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author | Paul Menage <menage@google.com> | 2008-07-25 01:47:02 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-07-25 10:53:36 -0700 |
commit | e37123953292146445c8629b3950d0513fd10ae2 (patch) | |
tree | 8481ef1898a61cb5438205df349e01c432a1d55b /kernel/cpuset.c | |
parent | af351026aafc8da16518a02b41c66d3e0c1cdef4 (diff) | |
download | linux-e37123953292146445c8629b3950d0513fd10ae2.tar.gz linux-e37123953292146445c8629b3950d0513fd10ae2.tar.bz2 linux-e37123953292146445c8629b3950d0513fd10ae2.zip |
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>
Diffstat (limited to 'kernel/cpuset.c')
-rw-r--r-- | kernel/cpuset.c | 109 |
1 files changed, 35 insertions, 74 deletions
diff --git a/kernel/cpuset.c b/kernel/cpuset.c index d5738910c34c..276ce7e4f1ab 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, }, |