Messages in this thread Patch in this message | | | From | Peter Williams <> | Date | Thu, 22 Jun 2006 11:53:19 +1000 | Subject | [PATCH 4/4] sched: Add procfs interface for CPU rate hard caps |
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This patch implements a procfs interface for hard CPU rate caps. Via files of the form /proc/<tgid>/task/<pid>/cpu_rate_hard_cap.
Signed-off-by: Peter Williams <pwil3058@bigpond.net.au> fs/proc/base.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++++ kernel/Kconfig.caps | 4 +++ 2 files changed, 63 insertions(+)
Index: MM-2.6.17-mm1/fs/proc/base.c =================================================================== --- MM-2.6.17-mm1.orig/fs/proc/base.c 2006-06-22 10:40:18.000000000 +1000 +++ MM-2.6.17-mm1/fs/proc/base.c 2006-06-22 10:49:55.000000000 +1000 @@ -171,6 +171,9 @@ enum pid_directory_inos { #ifdef CONFIG_CPU_RATE_CAPS PROC_TID_CPU_RATE_CAP, #endif +#ifdef CONFIG_CPU_RATE_HARD_CAPS + PROC_TID_CPU_RATE_HARD_CAP, +#endif #ifdef CONFIG_SECURITY PROC_TID_ATTR, PROC_TID_ATTR_CURRENT, @@ -288,6 +291,9 @@ static struct pid_entry tid_base_stuff[] #ifdef CONFIG_CPU_RATE_CAPS E(PROC_TID_CPU_RATE_CAP, "cpu_rate_cap", S_IFREG|S_IRUGO|S_IWUSR), #endif +#ifdef CONFIG_CPU_RATE_HARD_CAPS + E(PROC_TID_CPU_RATE_HARD_CAP, "cpu_rate_hard_cap", S_IFREG|S_IRUGO|S_IWUSR), +#endif {0,0,NULL,0} }; @@ -1095,6 +1101,54 @@ struct file_operations proc_cpu_rate_cap }; #endif +#ifdef CONFIG_CPU_RATE_HARD_CAPS +static ssize_t cpu_rate_hard_cap_read(struct file * file, char * buf, + size_t count, loff_t *ppos) +{ + struct task_struct *task = get_proc_task(file->f_dentry->d_inode); + char buffer[64]; + size_t len; + unsigned int cppt = get_cpu_rate_hard_cap(task); + + if (*ppos) + return 0; + *ppos = len = sprintf(buffer, "%u\n", cppt); + if (copy_to_user(buf, buffer, len)) + return -EFAULT; + + return len; +} + +static ssize_t cpu_rate_hard_cap_write(struct file * file, const char * buf, + size_t count, loff_t *ppos) +{ + struct task_struct *task = get_proc_task(file->f_dentry->d_inode); + char buffer[128] = ""; + char *endptr = NULL; + unsigned long hcppt; + int res; + + + if ((count > 63) || *ppos) + return -EFBIG; + if (copy_from_user(buffer, buf, count)) + return -EFAULT; + hcppt = simple_strtoul(buffer, &endptr, 0); + if ((endptr == buffer) || (hcppt == ULONG_MAX)) + return -EINVAL; + + if ((res = set_cpu_rate_hard_cap(task, hcppt)) != 0) + return res; + + return count; +} + +struct file_operations proc_cpu_rate_hard_cap_operations = { + read: cpu_rate_hard_cap_read, + write: cpu_rate_hard_cap_write, +}; +#endif + static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd) { struct inode *inode = dentry->d_inode; @@ -1862,6 +1916,11 @@ static struct dentry *proc_pident_lookup inode->i_fop = &proc_cpu_rate_cap_operations; break; #endif +#ifdef CONFIG_CPU_RATE_HARD_CAPS + case PROC_TID_CPU_RATE_HARD_CAP: + inode->i_fop = &proc_cpu_rate_hard_cap_operations; + break; +#endif default: printk("procfs: impossible type (%d)",p->type); iput(inode); Index: MM-2.6.17-mm1/kernel/Kconfig.caps =================================================================== --- MM-2.6.17-mm1.orig/kernel/Kconfig.caps 2006-06-22 10:48:54.000000000 +1000 +++ MM-2.6.17-mm1/kernel/Kconfig.caps 2006-06-22 10:52:21.000000000 +1000 @@ -26,3 +26,7 @@ config CPU_RATE_HARD_CAPS the rate of CPU usage by individual tasks. A task which has been allocated a hard CPU rate cap will be limited to that rate of CPU usage regardless of whether there is spare CPU resources available. + Task hard caps can be set/got via the procfs file system using + files of the form /proc/<tgid>/task/<pid>/cpu_rate_hard_cap in parts + per thousand. Minimum hard cap is 1 and the maximum hard cap is + 1000 (which means unlimited). -- Peter Williams pwil3058@bigpond.net.au
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