From 5baf98ba3b6a9d6ef304fdedfb0fce9185229aa6 Mon Sep 17 00:00:00 2001
From: Matthieu Hautreux <matthieu.hautreux@cea.fr>
Date: Wed, 12 Sep 2012 22:42:23 +0200
Subject: [PATCH] task/cgroup/memory - ensure that ConstrainSwapSpace=no is
correctly handled
Only set memory.memsw.limit_in_bytes to the computed amount of allowed
RAM+Swap when ConstrainSwapSpace=yes in cgroup.conf.
When ConstrainSwapSpace=yes and ConstrainRAMSpace=no, automatically
set AllowedRAMSpace to 100% in order to compute the memsw.limit based
on the allocated memory plus the allowed swap percent. Then use that
limit for both mem and mem+sw limits.
---
doc/man/man5/cgroup.conf.5 | 8 ++-
src/plugins/task/cgroup/task_cgroup_memory.c | 69 +++++++++++++++-----
2 files changed, 58 insertions(+), 19 deletions(-)
diff --git a/doc/man/man5/cgroup.conf.5 b/doc/man/man5/cgroup.conf.5
index c5807b680d5..69c48bbc574 100644
--- a/doc/man/man5/cgroup.conf.5
+++ b/doc/man/man5/cgroup.conf.5
@@ -93,7 +93,13 @@ Also see \fBAllowedRAMSpace\fR.
.TP
\fBConstrainSwapSpace\fR=<yes|no>
If configured to "yes" then constrain the job's swap space usage.
-The default value is "no".
+The default value is "no". Note that when set to "yes" and
+ConstrainRAMSpace is set to "no", AllowedRAMSpace is automatically set
+to 100% in order to limit the RAM+Swap amount to 100% of job's requirement
+plus the percent of allowed swap space. This amount is thus set to both
+RAM and RAM+Swap limits. This means that in that particular case,
+ConstrainRAMSpace is automatically enabled with the same limit than the one
+used to constrain swap space.
Also see \fBAllowedSwapSpace\fR.
.TP
diff --git a/src/plugins/task/cgroup/task_cgroup_memory.c b/src/plugins/task/cgroup/task_cgroup_memory.c
index a2e24806629..6ca89fe48ba 100644
--- a/src/plugins/task/cgroup/task_cgroup_memory.c
+++ b/src/plugins/task/cgroup/task_cgroup_memory.c
@@ -68,6 +68,9 @@ static xcgroup_t user_memory_cg;
static xcgroup_t job_memory_cg;
static xcgroup_t step_memory_cg;
+static bool constrain_ram_space;
+static bool constrain_swap_space;
+
static float allowed_ram_space; /* Allowed RAM in percent */
static float allowed_swap_space; /* Allowed Swap percent */
@@ -120,7 +123,21 @@ extern int task_cgroup_memory_init(slurm_cgroup_conf_t *slurm_cgroup_conf)
}
}
- allowed_ram_space = slurm_cgroup_conf->allowed_ram_space;
+ constrain_ram_space = slurm_cgroup_conf->constrain_ram_space;
+ constrain_swap_space = slurm_cgroup_conf->constrain_swap_space;
+
+ /*
+ * as the swap space threshold will be configured with a
+ * mem+swp parameter value, if RAM space is not monitored,
+ * set allowed RAM space to 100% of the job requested memory.
+ * It will help to construct the mem+swp value that will be
+ * used for both mem and mem+swp limit during memcg creation.
+ */
+ if ( constrain_ram_space )
+ allowed_ram_space = slurm_cgroup_conf->allowed_ram_space;
+ else
+ allowed_ram_space = 100.0;
+
allowed_swap_space = slurm_cgroup_conf->allowed_swap_space;
if ((totalram = (uint64_t) conf->real_memory_size) == 0)
@@ -131,17 +148,19 @@ extern int task_cgroup_memory_init(slurm_cgroup_conf_t *slurm_cgroup_conf)
max_swap += max_ram;
min_ram_space = slurm_cgroup_conf->min_ram_space * 1024 * 1024;
- debug ("task/cgroup/memory: total:%luM allowed:%.4g%%, swap:%.4g%%, "
- "max:%.4g%%(%luM) max+swap:%.4g%%(%luM) min:%uM",
- (unsigned long) totalram,
- allowed_ram_space,
- allowed_swap_space,
- slurm_cgroup_conf->max_ram_percent,
- (unsigned long) (max_ram/(1024*1024)),
- slurm_cgroup_conf->max_swap_percent,
- (unsigned long) (max_swap/(1024*1024)),
- (unsigned) slurm_cgroup_conf->min_ram_space);
-
+ debug ("task/cgroup/memory: total:%luM allowed:%.4g%%(%s), "
+ "swap:%.4g%%(%s), max:%.4g%%(%luM) max+swap:%.4g%%(%luM) min:%uM",
+ (unsigned long) totalram,
+ allowed_ram_space,
+ constrain_ram_space?"enforced":"permissive",
+ allowed_swap_space,
+ constrain_swap_space?"enforced":"permissive",
+ slurm_cgroup_conf->max_ram_percent,
+ (unsigned long) (max_ram/(1024*1024)),
+ slurm_cgroup_conf->max_swap_percent,
+ (unsigned long) (max_swap/(1024*1024)),
+ (unsigned) slurm_cgroup_conf->min_ram_space);
+
/*
* Warning: OOM Killer must be disabled for slurmstepd
* or it would be destroyed if the application use
@@ -264,14 +283,28 @@ static int memcg_initialize (xcgroup_ns_t *ns, xcgroup_t *cg,
}
xcgroup_set_param (cg, "memory.use_hierarchy","1");
+
+ /* when RAM space has not to be constrained and we are here, it
+ means that only Swap space has to be constrained. Thus set
+ RAM space limit to the mem+swap limit too */
+ if ( ! constrain_ram_space )
+ mlb = mls;
xcgroup_set_uint64_param (cg, "memory.limit_in_bytes", mlb);
- xcgroup_set_uint64_param (cg, "memory.memsw.limit_in_bytes", mls);
- info ("task/cgroup: %s: alloc=%luMB mem.limit=%luMB memsw.limit=%luMB",
- path,
- (unsigned long) mem_limit,
- (unsigned long) mlb/(1024*1024),
- (unsigned long) mls/(1024*1024));
+ /* this limit has to be set only if ConstrainSwapSpace is set to yes */
+ if ( constrain_swap_space ) {
+ xcgroup_set_uint64_param (cg, "memory.memsw.limit_in_bytes",
+ mls);
+ info ("task/cgroup: %s: alloc=%luMB mem.limit=%luMB "
+ "memsw.limit=%luMB",path,
+ (unsigned long) mem_limit,
+ (unsigned long) mlb/(1024*1024),
+ (unsigned long) mls/(1024*1024));
+ } else
+ info ("task/cgroup: %s: alloc=%luMB mem.limit=%luMB "
+ "memsw.limit=unlimited",path,
+ (unsigned long) mem_limit,
+ (unsigned long) mlb/(1024*1024));
return 0;
}
--
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