| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <20090107184123.18062.81916.sendpatchset@localhost.localdomain>
Date: Thu, 08 Jan 2009 00:11:23 +0530
From: Balbir Singh <balbir@...ux.vnet.ibm.com>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: Sudhir Kumar <skumar@...ux.vnet.ibm.com>,
YAMAMOTO Takashi <yamamoto@...inux.co.jp>,
Paul Menage <menage@...gle.com>, lizf@...fujitsu.com,
linux-kernel@...r.kernel.org, linux-mm@...ck.org,
David Rientjes <rientjes@...gle.com>,
Pavel Emelianov <xemul@...nvz.org>,
Balbir Singh <balbir@...ux.vnet.ibm.com>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>
Subject: [RFC][PATCH 2/4] Memory controller soft limit interface
From: Balbir Singh <balbir@...ux.vnet.ibm.com>
Add an interface to allow get/set of soft limits. Soft limits for memory plus
swap controller (memsw) is currently not supported. Resource counters have
been enhanced to support soft limits and new type RES_SOFT_LIMIT has been
added. Unlike hard limits, soft limits can be directly set and do not
need any reclaim or checks before setting them to a newer value.
Signed-off-by: Balbir Singh <balbir@...ux.vnet.ibm.com>
---
include/linux/res_counter.h | 39 ++++++++++++++++++++++++++++++++++
kernel/res_counter.c | 3 ++
mm/memcontrol.c | 20 +++++++++++++++++
3 files changed, 62 insertions(+)
diff -puN mm/memcontrol.c~memcg-add-soft-limit-interface mm/memcontrol.c
--- a/mm/memcontrol.c~memcg-add-soft-limit-interface
+++ a/mm/memcontrol.c
@@ -1811,6 +1811,20 @@ static int mem_cgroup_write(struct cgrou
else
ret = mem_cgroup_resize_memsw_limit(memcg, val);
break;
+ case RES_SOFT_LIMIT:
+ ret = res_counter_memparse_write_strategy(buffer, &val);
+ if (ret)
+ break;
+ /*
+ * For memsw, soft limits are hard to implement in terms
+ * of semantics, for now, we support soft limits for
+ * control without swap
+ */
+ if (type == _MEM)
+ ret = res_counter_set_soft_limit(&memcg->res, val);
+ else
+ ret = -EINVAL;
+ break;
default:
ret = -EINVAL; /* should be BUG() ? */
break;
@@ -2010,6 +2024,12 @@ static struct cftype mem_cgroup_files[]
.read_u64 = mem_cgroup_read,
},
{
+ .name = "soft_limit_in_bytes",
+ .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT),
+ .write_string = mem_cgroup_write,
+ .read_u64 = mem_cgroup_read,
+ },
+ {
.name = "failcnt",
.private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
.trigger = mem_cgroup_reset,
diff -puN include/linux/res_counter.h~memcg-add-soft-limit-interface include/linux/res_counter.h
--- a/include/linux/res_counter.h~memcg-add-soft-limit-interface
+++ a/include/linux/res_counter.h
@@ -35,6 +35,10 @@ struct res_counter {
*/
unsigned long long limit;
/*
+ * the limit that usage can be exceed
+ */
+ unsigned long long soft_limit;
+ /*
* the number of unsuccessful attempts to consume the resource
*/
unsigned long long failcnt;
@@ -85,6 +89,7 @@ enum {
RES_MAX_USAGE,
RES_LIMIT,
RES_FAILCNT,
+ RES_SOFT_LIMIT,
};
/*
@@ -130,6 +135,28 @@ static inline bool res_counter_limit_che
return false;
}
+/**
+ * Get the difference between the usage and the soft limit
+ * @cnt: The counter
+ *
+ * Returns 0 if usage is less than or equal to soft limit
+ * The difference between usage and soft limit, otherwise.
+ */
+static inline unsigned long long
+res_counter_soft_limit_excess(struct res_counter *cnt)
+{
+ unsigned long long excess;
+ unsigned long flags;
+
+ spin_lock_irqsave(&cnt->lock, flags);
+ if (cnt->usage <= cnt->soft_limit)
+ excess = 0;
+ else
+ excess = cnt->usage - cnt->soft_limit;
+ spin_unlock_irqrestore(&cnt->lock, flags);
+ return excess;
+}
+
/*
* Helper function to detect if the cgroup is within it's limit or
* not. It's currently called from cgroup_rss_prepare()
@@ -178,4 +205,16 @@ static inline int res_counter_set_limit(
return ret;
}
+static inline int
+res_counter_set_soft_limit(struct res_counter *cnt,
+ unsigned long long soft_limit)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&cnt->lock, flags);
+ cnt->soft_limit = soft_limit;
+ spin_unlock_irqrestore(&cnt->lock, flags);
+ return 0;
+}
+
#endif
diff -puN kernel/res_counter.c~memcg-add-soft-limit-interface kernel/res_counter.c
--- a/kernel/res_counter.c~memcg-add-soft-limit-interface
+++ a/kernel/res_counter.c
@@ -19,6 +19,7 @@ void res_counter_init(struct res_counter
{
spin_lock_init(&counter->lock);
counter->limit = (unsigned long long)LLONG_MAX;
+ counter->soft_limit = (unsigned long long)LLONG_MAX;
counter->parent = parent;
}
@@ -101,6 +102,8 @@ res_counter_member(struct res_counter *c
return &counter->limit;
case RES_FAILCNT:
return &counter->failcnt;
+ case RES_SOFT_LIMIT:
+ return &counter->soft_limit;
};
BUG();
_
--
Balbir
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists