[systemd-devel] [PATCH 2/4] cgroups: support for KernelMemoryLimit= setting
Mika Eloranta
mel at ohmu.fi
Wed Oct 9 16:18:35 PDT 2013
Add a KernelMemoryLimit setting that behaves the same way
as MemoryLimit, except that it controls the
memory.kmem.limit_in_bytes cgroup attribute.
---
man/systemd.resource-control.xml | 5 ++++-
src/core/cgroup.c | 18 +++++++++++++++++-
src/core/cgroup.h | 1 +
src/core/dbus-cgroup.c | 1 +
src/core/load-fragment-gperf.gperf.m4 | 1 +
src/core/load-fragment.c | 34 ++++++++++++++++++++++++++++++++++
src/core/load-fragment.h | 1 +
src/systemctl/systemctl.c | 3 ++-
8 files changed, 61 insertions(+), 3 deletions(-)
diff --git a/man/systemd.resource-control.xml b/man/systemd.resource-control.xml
index 606e078..dca7294 100644
--- a/man/systemd.resource-control.xml
+++ b/man/systemd.resource-control.xml
@@ -138,7 +138,7 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>.
</varlistentry>
<varlistentry>
- <term><varname>MemoryLimit=, MemoryAndSwapLimit=<replaceable>bytes</replaceable></varname></term>
+ <term><varname>MemoryLimit=, MemoryAndSwapLimit=, KernelMemoryLimit=<replaceable>bytes</replaceable></varname></term>
<listitem>
<para>Specify the limit on maximum memory usage of the
@@ -154,6 +154,9 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>.
<literal>memory.limit_in_bytes</literal> control group
attribute, which sets the limit for the sum of the used
memory and used swap space.
+ <literal>KernelMemoryLimit</literal> controls the
+ <literal>memory.kmem.limit_in_bytes</literal> control group
+ attribute, which limits the amound of kernel memory used.
For details about these control group attributes,
see <ulink
url="https://www.kernel.org/doc/Documentation/cgroups/memory.txt">memory.txt</ulink>.</para>
diff --git a/src/core/cgroup.c b/src/core/cgroup.c
index 3b465cc..41a09b0 100644
--- a/src/core/cgroup.c
+++ b/src/core/cgroup.c
@@ -35,6 +35,7 @@ void cgroup_context_init(CGroupContext *c) {
c->cpu_shares = 1024;
c->memory_limit = (uint64_t) -1;
c->memory_and_swap_limit = (uint64_t) -1;
+ c->kernel_memory_limit = (uint64_t) -1;
c->blockio_weight = 1000;
}
@@ -96,6 +97,7 @@ void cgroup_context_dump(CGroupContext *c, FILE* f, const char *prefix) {
"%sBlockIOWeight=%lu\n"
"%sMemoryLimit=%" PRIu64 "\n"
"%sMemoryAndSwapLimit=%" PRIu64 "\n"
+ "%sKernelMemoryLimit=%" PRIu64 "\n"
"%sDevicePolicy=%s\n",
prefix, yes_no(c->cpu_accounting),
prefix, yes_no(c->blockio_accounting),
@@ -104,6 +106,7 @@ void cgroup_context_dump(CGroupContext *c, FILE* f, const char *prefix) {
prefix, c->blockio_weight,
prefix, c->memory_limit,
prefix, c->memory_and_swap_limit,
+ prefix, c->kernel_memory_limit,
prefix, cgroup_device_policy_to_string(c->device_policy));
LIST_FOREACH(device_allow, a, c->device_allow)
@@ -278,6 +281,18 @@ void cgroup_context_apply(CGroupContext *c, CGroupControllerMask mask, const cha
if (r < 0)
log_error("Failed to set memory.memsw.limit_in_bytes on %s: %s", path, strerror(-r));
+
+ if (c->kernel_memory_limit != (uint64_t) -1) {
+ sprintf(buf, "%" PRIu64 "\n", c->kernel_memory_limit);
+ r = cg_set_attribute("memory", path, "memory.kmem.limit_in_bytes", buf);
+ } else {
+ r = cg_set_attribute("memory", path, "memory.kmem.limit_in_bytes", "-1");
+ if (r == -EACCES) /* CONFIG_MEMCG_KMEM not built into kernel, ignore */
+ r = 0;
+ }
+
+ if (r < 0)
+ log_error("Failed to set memory.kmem.limit_in_bytes on %s: %s", path, strerror(-r));
}
if (mask & CGROUP_DEVICE) {
@@ -341,7 +356,8 @@ CGroupControllerMask cgroup_context_get_mask(CGroupContext *c) {
if (c->memory_accounting ||
c->memory_limit != (uint64_t) -1 ||
- c->memory_and_swap_limit != (uint64_t) -1)
+ c->memory_and_swap_limit != (uint64_t) -1 ||
+ c->kernel_memory_limit != (uint64_t) -1)
mask |= CGROUP_MEMORY;
if (c->device_allow || c->device_policy != CGROUP_AUTO)
diff --git a/src/core/cgroup.h b/src/core/cgroup.h
index c84eed2..644eafc 100644
--- a/src/core/cgroup.h
+++ b/src/core/cgroup.h
@@ -78,6 +78,7 @@ struct CGroupContext {
uint64_t memory_limit;
uint64_t memory_and_swap_limit;
+ uint64_t kernel_memory_limit;
CGroupDevicePolicy device_policy;
LIST_HEAD(CGroupDeviceAllow, device_allow);
diff --git a/src/core/dbus-cgroup.c b/src/core/dbus-cgroup.c
index d86a03a..d398e7c 100644
--- a/src/core/dbus-cgroup.c
+++ b/src/core/dbus-cgroup.c
@@ -134,6 +134,7 @@ const BusProperty bus_cgroup_context_properties[] = {
{ "MemoryAccounting", bus_property_append_bool, "b", offsetof(CGroupContext, memory_accounting) },
{ "MemoryLimit", bus_property_append_uint64, "t", offsetof(CGroupContext, memory_limit) },
{ "MemoryAndSwapLimit", bus_property_append_uint64, "t", offsetof(CGroupContext, memory_and_swap_limit) },
+ { "KernelMemoryLimit", bus_property_append_uint64, "t", offsetof(CGroupContext, kernel_memory_limit) },
{ "DevicePolicy", bus_cgroup_append_device_policy, "s", offsetof(CGroupContext, device_policy) },
{ "DeviceAllow", bus_cgroup_append_device_allow, "a(ss)", 0 },
{}
diff --git a/src/core/load-fragment-gperf.gperf.m4 b/src/core/load-fragment-gperf.gperf.m4
index f86352e..e60d014 100644
--- a/src/core/load-fragment-gperf.gperf.m4
+++ b/src/core/load-fragment-gperf.gperf.m4
@@ -90,6 +90,7 @@ $1.CPUShares, config_parse_cpu_shares, 0,
$1.MemoryAccounting, config_parse_bool, 0, offsetof($1, cgroup_context.memory_accounting)
$1.MemoryLimit, config_parse_memory_limit, 0, offsetof($1, cgroup_context)
$1.MemoryAndSwapLimit, config_parse_memory_and_swap_limit, 0, offsetof($1, cgroup_context)
+$1.KernelMemoryLimit, config_parse_kernel_memory_limit, 0, offsetof($1, cgroup_context)
$1.DeviceAllow, config_parse_device_allow, 0, offsetof($1, cgroup_context)
$1.DevicePolicy, config_parse_device_policy, 0, offsetof($1, cgroup_context.device_policy)
$1.BlockIOAccounting, config_parse_bool, 0, offsetof($1, cgroup_context.blockio_accounting)
diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c
index 6dabf4c..91a9971 100644
--- a/src/core/load-fragment.c
+++ b/src/core/load-fragment.c
@@ -2105,6 +2105,39 @@ int config_parse_memory_and_swap_limit(
return 0;
}
+int config_parse_kernel_memory_limit(
+ const char *unit,
+ const char *filename,
+ unsigned line,
+ const char *section,
+ const char *lvalue,
+ int ltype,
+ const char *rvalue,
+ void *data,
+ void *userdata) {
+
+ CGroupContext *c = data;
+ off_t bytes;
+ int r;
+
+ if (isempty(rvalue)) {
+ c->kernel_memory_limit = (uint64_t) -1;
+ return 0;
+ }
+
+ assert_cc(sizeof(uint64_t) == sizeof(off_t));
+
+ r = parse_bytes(rvalue, &bytes);
+ if (r < 0) {
+ log_syntax(unit, LOG_ERR, filename, line, EINVAL,
+ "Kernel memory limit '%s' invalid. Ignoring.", rvalue);
+ return 0;
+ }
+
+ c->kernel_memory_limit = (uint64_t) bytes;
+ return 0;
+}
+
int config_parse_device_allow(
const char *unit,
const char *filename,
@@ -2746,6 +2779,7 @@ void unit_dump_config_items(FILE *f) {
{ config_parse_cpu_shares, "SHARES" },
{ config_parse_memory_limit, "LIMIT" },
{ config_parse_memory_and_swap_limit, "LIMIT" },
+ { config_parse_kernel_memory_limit, "LIMIT" },
{ config_parse_device_allow, "DEVICE" },
{ config_parse_device_policy, "POLICY" },
{ config_parse_blockio_bandwidth, "BANDWIDTH" },
diff --git a/src/core/load-fragment.h b/src/core/load-fragment.h
index 846825c..c79c7f2 100644
--- a/src/core/load-fragment.h
+++ b/src/core/load-fragment.h
@@ -79,6 +79,7 @@ int config_parse_unit_slice(const char *unit, const char *filename, unsigned lin
int config_parse_cpu_shares(const char *unit, const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_memory_limit(const char *unit, const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_memory_and_swap_limit(const char *unit, const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_kernel_memory_limit(const char *unit, const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_device_policy(const char *unit, const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_device_allow(const char *unit, const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_blockio_weight(const char *unit, const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
diff --git a/src/systemctl/systemctl.c b/src/systemctl/systemctl.c
index 9e6bb06..cf00334 100644
--- a/src/systemctl/systemctl.c
+++ b/src/systemctl/systemctl.c
@@ -3658,7 +3658,8 @@ static int append_assignment(DBusMessageIter *iter, const char *assignment) {
!dbus_message_iter_append_basic(&sub, DBUS_TYPE_BOOLEAN, &b))
return log_oom();
- } else if (streq(field, "MemoryLimit") || streq(field, "MemoryAndSwapLimit")) {
+ } else if (streq(field, "MemoryLimit") || streq(field, "MemoryAndSwapLimit")
+ || streq(field, "KernelMemoryLimit")) {
off_t bytes;
uint64_t u;
--
1.8.3.2
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