From: Andrea Arcangeli <andrea@suse.de>,
<garloff@suse.de>
This is protect-pids, a patch to allow the admin to tune the oom killer.
The tweak is inherited between parent and child so it's easy to write a
wrapper for complex apps.
I made used_math a char at the light of later patches. Current patch
breaks alpha, but future patches will fix it.
Signed-off-by: Andrea Arcangeli <andrea@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/fs/proc/base.c | 79 ++++++++++++++++++++++++++++++++++++++++++
25-akpm/include/linux/sched.h | 14 ++++++-
25-akpm/mm/oom_kill.c | 13 ++++++
3 files changed, 104 insertions(+), 2 deletions(-)
diff -puN fs/proc/base.c~mm-oom-killer-tunable fs/proc/base.c
--- 25/fs/proc/base.c~mm-oom-killer-tunable 2005-01-22 23:12:35.019369744 -0800
+++ 25-akpm/fs/proc/base.c 2005-01-22 23:12:35.033367616 -0800
@@ -72,6 +72,8 @@ enum pid_directory_inos {
PROC_TGID_ATTR_FSCREATE,
#endif
PROC_TGID_FD_DIR,
+ PROC_TGID_OOM_SCORE,
+ PROC_TGID_OOM_ADJUST,
PROC_TID_INO,
PROC_TID_STATUS,
PROC_TID_MEM,
@@ -98,6 +100,8 @@ enum pid_directory_inos {
PROC_TID_ATTR_FSCREATE,
#endif
PROC_TID_FD_DIR = 0x8000, /* 0x8000-0xffff */
+ PROC_TID_OOM_SCORE,
+ PROC_TID_OOM_ADJUST,
};
struct pid_entry {
@@ -133,6 +137,8 @@ static struct pid_entry tgid_base_stuff[
#ifdef CONFIG_SCHEDSTATS
E(PROC_TGID_SCHEDSTAT, "schedstat", S_IFREG|S_IRUGO),
#endif
+ E(PROC_TGID_OOM_SCORE, "oom_score",S_IFREG|S_IRUGO),
+ E(PROC_TGID_OOM_ADJUST,"oom_adj", S_IFREG|S_IRUGO|S_IWUSR),
{0,0,NULL,0}
};
static struct pid_entry tid_base_stuff[] = {
@@ -158,6 +164,8 @@ static struct pid_entry tid_base_stuff[]
#ifdef CONFIG_SCHEDSTATS
E(PROC_TID_SCHEDSTAT, "schedstat",S_IFREG|S_IRUGO),
#endif
+ E(PROC_TID_OOM_SCORE, "oom_score",S_IFREG|S_IRUGO),
+ E(PROC_TID_OOM_ADJUST, "oom_adj", S_IFREG|S_IRUGO|S_IWUSR),
{0,0,NULL,0}
};
@@ -384,6 +392,18 @@ static int proc_pid_schedstat(struct tas
}
#endif
+/* The badness from the OOM killer */
+unsigned long badness(struct task_struct *p, unsigned long uptime);
+static int proc_oom_score(struct task_struct *task, char *buffer)
+{
+ unsigned long points;
+ struct timespec uptime;
+
+ do_posix_clock_monotonic_gettime(&uptime);
+ points = badness(task, uptime.tv_sec);
+ return sprintf(buffer, "%lu\n", points);
+}
+
/************************************************************************/
/* Here the fs part begins */
/************************************************************************/
@@ -657,6 +677,56 @@ static struct file_operations proc_mem_o
.open = mem_open,
};
+static ssize_t oom_adjust_read(struct file *file, char *buf,
+ size_t count, loff_t *ppos)
+{
+ struct task_struct *task = proc_task(file->f_dentry->d_inode);
+ char buffer[8];
+ size_t len;
+ int oom_adjust = task->oomkilladj;
+ loff_t __ppos = *ppos;
+
+ len = sprintf(buffer, "%i\n", oom_adjust);
+ if (__ppos >= len)
+ return 0;
+ if (count > len-__ppos)
+ count = len-__ppos;
+ if (copy_to_user(buf, buffer + __ppos, count))
+ return -EFAULT;
+ *ppos = __ppos + count;
+ return count;
+}
+
+static ssize_t oom_adjust_write(struct file *file, const char *buf,
+ size_t count, loff_t *ppos)
+{
+ struct task_struct *task = proc_task(file->f_dentry->d_inode);
+ char buffer[8], *end;
+ int oom_adjust;
+
+ if (!capable(CAP_SYS_RESOURCE))
+ return -EPERM;
+ memset(buffer, 0, 8);
+ if (count > 6)
+ count = 6;
+ if (copy_from_user(buffer, buf, count))
+ return -EFAULT;
+ oom_adjust = simple_strtol(buffer, &end, 0);
+ if (oom_adjust < -16 || oom_adjust > 15)
+ return -EINVAL;
+ if (*end == '\n')
+ end++;
+ task->oomkilladj = oom_adjust;
+ if (end - buffer == 0)
+ return -EIO;
+ return end - buffer;
+}
+
+static struct file_operations proc_oom_adjust_operations = {
+ read: oom_adjust_read,
+ write: oom_adjust_write,
+};
+
static struct inode_operations proc_mem_inode_operations = {
.permission = proc_permission,
};
@@ -1336,6 +1406,15 @@ static struct dentry *proc_pident_lookup
ei->op.proc_read = proc_pid_schedstat;
break;
#endif
+ case PROC_TID_OOM_SCORE:
+ case PROC_TGID_OOM_SCORE:
+ inode->i_fop = &proc_info_file_operations;
+ ei->op.proc_read = proc_oom_score;
+ break;
+ case PROC_TID_OOM_ADJUST:
+ case PROC_TGID_OOM_ADJUST:
+ inode->i_fop = &proc_oom_adjust_operations;
+ break;
default:
printk("procfs: impossible type (%d)",p->type);
iput(inode);
diff -puN include/linux/sched.h~mm-oom-killer-tunable include/linux/sched.h
--- 25/include/linux/sched.h~mm-oom-killer-tunable 2005-01-22 23:12:35.021369440 -0800
+++ 25-akpm/include/linux/sched.h 2005-01-22 23:12:35.035367312 -0800
@@ -614,7 +614,19 @@ struct task_struct {
struct key *process_keyring; /* keyring private to this process (CLONE_THREAD) */
struct key *thread_keyring; /* keyring private to this thread */
#endif
- unsigned short used_math;
+/*
+ * Must be changed atomically so it shouldn't be
+ * be a shareable bitflag.
+ */
+ unsigned char used_math;
+/*
+ * OOM kill score adjustment (bit shift).
+ * Cannot live together with used_math since
+ * used_math and oomkilladj can be changed at the
+ * same time, so they would race if they're in the
+ * same atomic block.
+ */
+ short oomkilladj;
char comm[TASK_COMM_LEN];
/* file system info */
int link_count, total_link_count;
diff -puN mm/oom_kill.c~mm-oom-killer-tunable mm/oom_kill.c
--- 25/mm/oom_kill.c~mm-oom-killer-tunable 2005-01-22 23:12:35.025368832 -0800
+++ 25-akpm/mm/oom_kill.c 2005-01-22 23:12:35.036367160 -0800
@@ -42,7 +42,7 @@
* of least surprise ... (be careful when you change it)
*/
-static unsigned long badness(struct task_struct *p, unsigned long uptime)
+unsigned long badness(struct task_struct *p, unsigned long uptime)
{
unsigned long points, cpu_time, run_time, s;
@@ -99,6 +99,17 @@ static unsigned long badness(struct task
*/
if (cap_t(p->cap_effective) & CAP_TO_MASK(CAP_SYS_RAWIO))
points /= 4;
+
+ /*
+ * Adjust the score by oomkilladj.
+ */
+ if (p->oomkilladj) {
+ if (p->oomkilladj > 0)
+ points <<= p->oomkilladj;
+ else
+ points >>= -(p->oomkilladj);
+ }
+
#ifdef DEBUG
printk(KERN_DEBUG "OOMkill: task %d (%s) got %d points\n",
p->pid, p->comm, points);
_