Satoshi UCHIDA
2008-Oct-29 09:12 UTC
[PATCH][cfq-cgroups] Introduce cgroups structure with ioprio entry.
This patch introcude cfq_cgroup structure which is type for group control within expanded CFQ scheduler. In addition, the cfq_cgroup structure has "ioprio" entry which is preference of group for I/O. Signed-off-by: Satoshi UCHIDA <s-uchida at ap.jp.nec.com> --- block/cfq-cgroup.c | 148 +++++++++++++++++++++++++++++++++++++++++ include/linux/cgroup_subsys.h | 6 ++ 2 files changed, 154 insertions(+), 0 deletions(-) diff --git a/block/cfq-cgroup.c b/block/cfq-cgroup.c index aaa00ef..733980d 100644 --- a/block/cfq-cgroup.c +++ b/block/cfq-cgroup.c @@ -15,6 +15,154 @@ #include <linux/cgroup.h> #include <linux/cfq-iosched.h> +#define CFQ_CGROUP_MAX_IOPRIO (7) + + +struct cfq_cgroup { + struct cgroup_subsys_state css; + unsigned int ioprio; +}; + +static inline struct cfq_cgroup *cgroup_to_cfq_cgroup(struct cgroup *cont) +{ + return container_of(cgroup_subsys_state(cont, cfq_subsys_id), + struct cfq_cgroup, css); +} + +static inline struct cfq_cgroup *task_to_cfq_cgroup(struct task_struct *tsk) +{ + return container_of(task_subsys_state(tsk, cfq_subsys_id), + struct cfq_cgroup, css); +} + + +static struct cgroup_subsys_state * +cfq_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) +{ + struct cfq_cgroup *cfqc; + + if (!capable(CAP_SYS_ADMIN)) + return ERR_PTR(-EPERM); + + if (!cgroup_is_descendant(cont)) + return ERR_PTR(-EPERM); + + cfqc = kzalloc(sizeof(struct cfq_cgroup), GFP_KERNEL); + if (unlikely(!cfqc)) + return ERR_PTR(-ENOMEM); + + cfqc->ioprio = 3; + + return &cfqc->css; +} + +static void cfq_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cont) +{ + kfree(cgroup_to_cfq_cgroup(cont)); +} + +static ssize_t cfq_cgroup_read(struct cgroup *cont, struct cftype *cft, + struct file *file, char __user *userbuf, + size_t nbytes, loff_t *ppos) +{ + struct cfq_cgroup *cfqc; + char *page; + ssize_t ret; + + page = (char *)__get_free_page(GFP_TEMPORARY); + if (!page) + return -ENOMEM; + + cgroup_lock(); + if (cgroup_is_removed(cont)) { + cgroup_unlock(); + ret = -ENODEV; + goto out; + } + + cfqc = cgroup_to_cfq_cgroup(cont); + + cgroup_unlock(); + + /* print priority */ + ret = snprintf(page, PAGE_SIZE, "%d \n", cfqc->ioprio); + + ret = simple_read_from_buffer(userbuf, nbytes, ppos, page, ret); + +out: + free_page((unsigned long)page); + return ret; +} + +static ssize_t cfq_cgroup_write(struct cgroup *cont, struct cftype *cft, + struct file *file, const char __user *userbuf, + size_t nbytes, loff_t *ppos) +{ + struct cfq_cgroup *cfqc; + ssize_t ret; + long new_prio; + int err; + char *buffer = NULL; + + cgroup_lock(); + if (cgroup_is_removed(cont)) { + cgroup_unlock(); + ret = -ENODEV; + goto out; + } + + cfqc = cgroup_to_cfq_cgroup(cont); + cgroup_unlock(); + + /* set priority */ + buffer = kmalloc(nbytes + 1, GFP_KERNEL); + if (buffer == NULL) + return -ENOMEM; + + if (copy_from_user(buffer, userbuf, nbytes)) { + ret = -EFAULT; + goto out; + } + buffer[nbytes] = 0; + + err = strict_strtoul(buffer, 10, &new_prio); + if ((err) || ((new_prio < 0) || (new_prio > CFQ_CGROUP_MAX_IOPRIO))) { + ret = -EINVAL; + goto out; + } + + cfqc->ioprio = new_prio; + + ret = nbytes; + +out: + kfree(buffer); + + return ret; +} + +static struct cftype files[] = { + { + .name = "ioprio", + .read = cfq_cgroup_read, + .write = cfq_cgroup_write, + }, +}; + +static int cfq_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cont) +{ + return cgroup_add_files(cont, ss, files, ARRAY_SIZE(files)); +} + +struct cgroup_subsys cfq_subsys = { + .name = "cfq", + .create = cfq_cgroup_create, + .destroy = cfq_cgroup_destroy, + .populate = cfq_cgroup_populate, + .subsys_id = cfq_subsys_id, +}; + + /* * sysfs parts below --> */ diff --git a/include/linux/cgroup_subsys.h b/include/linux/cgroup_subsys.h index 9c22396..a9482aa 100644 --- a/include/linux/cgroup_subsys.h +++ b/include/linux/cgroup_subsys.h @@ -54,3 +54,9 @@ SUBSYS(freezer) #endif /* */ + +#ifdef CONFIG_IOSCHED_CFQ_CGROUP +SUBSYS(cfq) +#endif + +/* */ -- 1.5.6.5
Possibly Parallel Threads
- [PATCH][cfq-cgroups] Introduce ioprio class for top layer.
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