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Merge branch 'cgroup/for-4.11-rdmacg' into cgroup/for-4.11

Browse source 
Merge in to resolve conflicts in Documentation/cgroup-v2.txt.  The
conflicts are from multiple section additions and trivial to resolve.

Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Tejun Heo 2017-02-02 13:50:35 -05:00
commit 63f1ca5945
14 changed files with 1071 additions and 10 deletions
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109
Documentation/cgroup-v1/rdma.txt Normal file
View file

@ -0,0 +1,109 @@
RDMA Controller
----------------
Contents
--------
1. Overview
1-1. What is RDMA controller?
1-2. Why RDMA controller needed?
1-3. How is RDMA controller implemented?
2. Usage Examples
1. Overview
1-1. What is RDMA controller?
-----------------------------
RDMA controller allows user to limit RDMA/IB specific resources that a given
set of processes can use. These processes are grouped using RDMA controller.
RDMA controller defines two resources which can be limited for processes of a
cgroup.
1-2. Why RDMA controller needed?
--------------------------------
Currently user space applications can easily take away all the rdma verb
specific resources such as AH, CQ, QP, MR etc. Due to which other applications
in other cgroup or kernel space ULPs may not even get chance to allocate any
rdma resources. This can leads to service unavailability.
Therefore RDMA controller is needed through which resource consumption
of processes can be limited. Through this controller different rdma
resources can be accounted.
1-3. How is RDMA controller implemented?
----------------------------------------
RDMA cgroup allows limit configuration of resources. Rdma cgroup maintains
resource accounting per cgroup, per device using resource pool structure.
Each such resource pool is limited up to 64 resources in given resource pool
by rdma cgroup, which can be extended later if required.
This resource pool object is linked to the cgroup css. Typically there
are 0 to 4 resource pool instances per cgroup, per device in most use cases.
But nothing limits to have it more. At present hundreds of RDMA devices per
single cgroup may not be handled optimally, however there is no
known use case or requirement for such configuration either.
Since RDMA resources can be allocated from any process and can be freed by any
of the child processes which shares the address space, rdma resources are
always owned by the creator cgroup css. This allows process migration from one
to other cgroup without major complexity of transferring resource ownership;
because such ownership is not really present due to shared nature of
rdma resources. Linking resources around css also ensures that cgroups can be
deleted after processes migrated. This allow progress migration as well with
active resources, even though that is not a primary use case.
Whenever RDMA resource charging occurs, owner rdma cgroup is returned to
the caller. Same rdma cgroup should be passed while uncharging the resource.
This also allows process migrated with active RDMA resource to charge
to new owner cgroup for new resource. It also allows to uncharge resource of
a process from previously charged cgroup which is migrated to new cgroup,
even though that is not a primary use case.
Resource pool object is created in following situations.
(a) User sets the limit and no previous resource pool exist for the device
of interest for the cgroup.
(b) No resource limits were configured, but IB/RDMA stack tries to
charge the resource. So that it correctly uncharge them when applications are
running without limits and later on when limits are enforced during uncharging,
otherwise usage count will drop to negative.
Resource pool is destroyed if all the resource limits are set to max and
it is the last resource getting deallocated.
User should set all the limit to max value if it intents to remove/unconfigure
the resource pool for a particular device.
IB stack honors limits enforced by the rdma controller. When application
query about maximum resource limits of IB device, it returns minimum of
what is configured by user for a given cgroup and what is supported by
IB device.
Following resources can be accounted by rdma controller.
hca_handle Maximum number of HCA Handles
hca_object Maximum number of HCA Objects
2. Usage Examples
-----------------
(a) Configure resource limit:
echo mlx4_0 hca_handle=2 hca_object=2000 > /sys/fs/cgroup/rdma/1/rdma.max
echo ocrdma1 hca_handle=3 > /sys/fs/cgroup/rdma/2/rdma.max
(b) Query resource limit:
cat /sys/fs/cgroup/rdma/2/rdma.max
#Output:
mlx4_0 hca_handle=2 hca_object=2000
ocrdma1 hca_handle=3 hca_object=max
(c) Query current usage:
cat /sys/fs/cgroup/rdma/2/rdma.current
#Output:
mlx4_0 hca_handle=1 hca_object=20
ocrdma1 hca_handle=1 hca_object=23
(d) Delete resource limit:
echo echo mlx4_0 hca_handle=max hca_object=max > /sys/fs/cgroup/rdma/1/rdma.max

46
Documentation/cgroup-v2.txt
View file

@ -49,8 +49,10 @@ CONTENTS
5-3-2. Writeback
5-4. PID
5-4-1. PID Interface Files
5-5. Misc
5-5-1. perf_event
5-5. RDMA
5-5-1. RDMA Interface Files
5-6. Misc
5-6-1. perf_event
6. Namespace
6-1. Basics
6-2. The Root and Views
@ -1160,9 +1162,45 @@ through fork() or clone(). These will return -EAGAIN if the creation
of a new process would cause a cgroup policy to be violated.
5-5. Misc
5-5. RDMA
5-5-1. perf_event
The "rdma" controller regulates the distribution and accounting of
of RDMA resources.
5-5-1. RDMA Interface Files
rdma.max
A readwrite nested-keyed file that exists for all the cgroups
except root that describes current configured resource limit
for a RDMA/IB device.
Lines are keyed by device name and are not ordered.
Each line contains space separated resource name and its configured
limit that can be distributed.
The following nested keys are defined.
hca_handle Maximum number of HCA Handles
hca_object Maximum number of HCA Objects
An example for mlx4 and ocrdma device follows.
mlx4_0 hca_handle=2 hca_object=2000
ocrdma1 hca_handle=3 hca_object=max
rdma.current
A read-only file that describes current resource usage.
It exists for all the cgroup except root.
An example for mlx4 and ocrdma device follows.
mlx4_0 hca_handle=1 hca_object=20
ocrdma1 hca_handle=1 hca_object=23
5-6. Misc
5-6-1. perf_event
perf_event controller, if not mounted on a legacy hierarchy, is
automatically enabled on the v2 hierarchy so that perf events can

1
drivers/infiniband/core/Makefile
View file

@ -13,6 +13,7 @@ ib_core-y := packer.o ud_header.o verbs.o cq.o rw.o sysfs.o \
multicast.o mad.o smi.o agent.o mad_rmpp.o
ib_core-$(CONFIG_INFINIBAND_USER_MEM) += umem.o
ib_core-$(CONFIG_INFINIBAND_ON_DEMAND_PAGING) += umem_odp.o umem_rbtree.o
ib_core-$(CONFIG_CGROUP_RDMA) += cgroup.o
ib_cm-y := cm.o

62
drivers/infiniband/core/cgroup.c Normal file
View file

@ -0,0 +1,62 @@
/*
* Copyright (C) 2016 Parav Pandit <pandit.parav@gmail.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*/
#include "core_priv.h"
/**
* ib_device_register_rdmacg - register with rdma cgroup.
* @device: device to register to participate in resource
* accounting by rdma cgroup.
*
* Register with the rdma cgroup. Should be called before
* exposing rdma device to user space applications to avoid
* resource accounting leak.
* Returns 0 on success or otherwise failure code.
*/
int ib_device_register_rdmacg(struct ib_device *device)
{
device->cg_device.name = device->name;
return rdmacg_register_device(&device->cg_device);
}
/**
* ib_device_unregister_rdmacg - unregister with rdma cgroup.
* @device: device to unregister.
*
* Unregister with the rdma cgroup. Should be called after
* all the resources are deallocated, and after a stage when any
* other resource allocation by user application cannot be done
* for this device to avoid any leak in accounting.
*/
void ib_device_unregister_rdmacg(struct ib_device *device)
{
rdmacg_unregister_device(&device->cg_device);
}
int ib_rdmacg_try_charge(struct ib_rdmacg_object *cg_obj,
struct ib_device *device,
enum rdmacg_resource_type resource_index)
{
return rdmacg_try_charge(&cg_obj->cg, &device->cg_device,
resource_index);
}
EXPORT_SYMBOL(ib_rdmacg_try_charge);
void ib_rdmacg_uncharge(struct ib_rdmacg_object *cg_obj,
struct ib_device *device,
enum rdmacg_resource_type resource_index)
{
rdmacg_uncharge(cg_obj->cg, &device->cg_device,
resource_index);
}
EXPORT_SYMBOL(ib_rdmacg_uncharge);

30
drivers/infiniband/core/core_priv.h
View file

@ -35,6 +35,7 @@
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/cgroup_rdma.h>
#include <rdma/ib_verbs.h>
@ -121,6 +122,35 @@ int ib_cache_setup_one(struct ib_device *device);
void ib_cache_cleanup_one(struct ib_device *device);
void ib_cache_release_one(struct ib_device *device);
#ifdef CONFIG_CGROUP_RDMA
int ib_device_register_rdmacg(struct ib_device *device);
void ib_device_unregister_rdmacg(struct ib_device *device);
int ib_rdmacg_try_charge(struct ib_rdmacg_object *cg_obj,
struct ib_device *device,
enum rdmacg_resource_type resource_index);
void ib_rdmacg_uncharge(struct ib_rdmacg_object *cg_obj,
struct ib_device *device,
enum rdmacg_resource_type resource_index);
#else
static inline int ib_device_register_rdmacg(struct ib_device *device)
{ return 0; }
static inline void ib_device_unregister_rdmacg(struct ib_device *device)
{ }
static inline int ib_rdmacg_try_charge(struct ib_rdmacg_object *cg_obj,
struct ib_device *device,
enum rdmacg_resource_type resource_index)
{ return 0; }
static inline void ib_rdmacg_uncharge(struct ib_rdmacg_object *cg_obj,
struct ib_device *device,
enum rdmacg_resource_type resource_index)
{ }
#endif
static inline bool rdma_is_upper_dev_rcu(struct net_device *dev,
struct net_device *upper)
{

10
drivers/infiniband/core/device.c
View file

@ -360,10 +360,18 @@ int ib_register_device(struct ib_device *device,
goto out;
}
ret = ib_device_register_rdmacg(device);
if (ret) {
pr_warn("Couldn't register device with rdma cgroup\n");
ib_cache_cleanup_one(device);
goto out;
}
memset(&device->attrs, 0, sizeof(device->attrs));
ret = device->query_device(device, &device->attrs, &uhw);
if (ret) {
pr_warn("Couldn't query the device attributes\n");
ib_device_unregister_rdmacg(device);
ib_cache_cleanup_one(device);
goto out;
}
@ -372,6 +380,7 @@ int ib_register_device(struct ib_device *device,
if (ret) {
pr_warn("Couldn't register device %s with driver model\n",
device->name);
ib_device_unregister_rdmacg(device);
ib_cache_cleanup_one(device);
goto out;
}
@ -421,6 +430,7 @@ void ib_unregister_device(struct ib_device *device)
mutex_unlock(&device_mutex);
ib_device_unregister_rdmacg(device);
ib_device_unregister_sysfs(device);
ib_cache_cleanup_one(device);

102
drivers/infiniband/core/uverbs_cmd.c
View file

@ -316,6 +316,7 @@ ssize_t ib_uverbs_get_context(struct ib_uverbs_file *file,
struct ib_udata udata;
struct ib_ucontext *ucontext;
struct file *filp;
struct ib_rdmacg_object cg_obj;
int ret;
if (out_len < sizeof resp)
@ -335,13 +336,18 @@ ssize_t ib_uverbs_get_context(struct ib_uverbs_file *file,
(unsigned long) cmd.response + sizeof resp,
in_len - sizeof cmd, out_len - sizeof resp);
ret = ib_rdmacg_try_charge(&cg_obj, ib_dev, RDMACG_RESOURCE_HCA_HANDLE);
if (ret)
goto err;
ucontext = ib_dev->alloc_ucontext(ib_dev, &udata);
if (IS_ERR(ucontext)) {
ret = PTR_ERR(ucontext);
goto err;
goto err_alloc;
}
ucontext->device = ib_dev;
ucontext->cg_obj = cg_obj;
INIT_LIST_HEAD(&ucontext->pd_list);
INIT_LIST_HEAD(&ucontext->mr_list);
INIT_LIST_HEAD(&ucontext->mw_list);
@ -407,6 +413,9 @@ err_free:
put_pid(ucontext->tgid);
ib_dev->dealloc_ucontext(ucontext);
err_alloc:
ib_rdmacg_uncharge(&cg_obj, ib_dev, RDMACG_RESOURCE_HCA_HANDLE);
err:
mutex_unlock(&file->mutex);
return ret;
@ -561,6 +570,13 @@ ssize_t ib_uverbs_alloc_pd(struct ib_uverbs_file *file,
return -ENOMEM;
init_uobj(uobj, 0, file->ucontext, &pd_lock_class);
ret = ib_rdmacg_try_charge(&uobj->cg_obj, ib_dev,
RDMACG_RESOURCE_HCA_OBJECT);
if (ret) {
kfree(uobj);
return ret;
}
down_write(&uobj->mutex);
pd = ib_dev->alloc_pd(ib_dev, file->ucontext, &udata);
@ -605,6 +621,7 @@ err_idr:
ib_dealloc_pd(pd);
err:
ib_rdmacg_uncharge(&uobj->cg_obj, ib_dev, RDMACG_RESOURCE_HCA_OBJECT);
put_uobj_write(uobj);
return ret;
}
@ -637,6 +654,8 @@ ssize_t ib_uverbs_dealloc_pd(struct ib_uverbs_file *file,
if (ret)
goto err_put;
ib_rdmacg_uncharge(&uobj->cg_obj, ib_dev, RDMACG_RESOURCE_HCA_OBJECT);
uobj->live = 0;
put_uobj_write(uobj);
@ -1006,6 +1025,10 @@ ssize_t ib_uverbs_reg_mr(struct ib_uverbs_file *file,
goto err_put;
}
}
ret = ib_rdmacg_try_charge(&uobj->cg_obj, ib_dev,
RDMACG_RESOURCE_HCA_OBJECT);
if (ret)
goto err_charge;
mr = pd->device->reg_user_mr(pd, cmd.start, cmd.length, cmd.hca_va,
cmd.access_flags, &udata);
@ -1054,6 +1077,9 @@ err_unreg:
ib_dereg_mr(mr);
err_put:
ib_rdmacg_uncharge(&uobj->cg_obj, ib_dev, RDMACG_RESOURCE_HCA_OBJECT);
err_charge:
put_pd_read(pd);
err_free:
@ -1178,6 +1204,8 @@ ssize_t ib_uverbs_dereg_mr(struct ib_uverbs_file *file,
if (ret)
return ret;
ib_rdmacg_uncharge(&uobj->cg_obj, ib_dev, RDMACG_RESOURCE_HCA_OBJECT);
idr_remove_uobj(&ib_uverbs_mr_idr, uobj);
mutex_lock(&file->mutex);
@ -1226,6 +1254,11 @@ ssize_t ib_uverbs_alloc_mw(struct ib_uverbs_file *file,
in_len - sizeof(cmd) - sizeof(struct ib_uverbs_cmd_hdr),
out_len - sizeof(resp));
ret = ib_rdmacg_try_charge(&uobj->cg_obj, ib_dev,
RDMACG_RESOURCE_HCA_OBJECT);
if (ret)
goto err_charge;
mw = pd->device->alloc_mw(pd, cmd.mw_type, &udata);
if (IS_ERR(mw)) {
ret = PTR_ERR(mw);
@ -1271,6 +1304,9 @@ err_unalloc:
uverbs_dealloc_mw(mw);
err_put:
ib_rdmacg_uncharge(&uobj->cg_obj, ib_dev, RDMACG_RESOURCE_HCA_OBJECT);
err_charge:
put_pd_read(pd);
err_free:
@ -1306,6 +1342,8 @@ ssize_t ib_uverbs_dealloc_mw(struct ib_uverbs_file *file,
if (ret)
return ret;
ib_rdmacg_uncharge(&uobj->cg_obj, ib_dev, RDMACG_RESOURCE_HCA_OBJECT);
idr_remove_uobj(&ib_uverbs_mw_idr, uobj);
mutex_lock(&file->mutex);
@ -1405,6 +1443,11 @@ static struct ib_ucq_object *create_cq(struct ib_uverbs_file *file,
if (cmd_sz > offsetof(typeof(*cmd), flags) + sizeof(cmd->flags))
attr.flags = cmd->flags;
ret = ib_rdmacg_try_charge(&obj->uobject.cg_obj, ib_dev,
RDMACG_RESOURCE_HCA_OBJECT);
if (ret)
goto err_charge;
cq = ib_dev->create_cq(ib_dev, &attr,
file->ucontext, uhw);
if (IS_ERR(cq)) {
@ -1452,6 +1495,10 @@ err_free:
ib_destroy_cq(cq);
err_file:
ib_rdmacg_uncharge(&obj->uobject.cg_obj, ib_dev,
RDMACG_RESOURCE_HCA_OBJECT);
err_charge:
if (ev_file)
ib_uverbs_release_ucq(file, ev_file, obj);
@ -1732,6 +1779,8 @@ ssize_t ib_uverbs_destroy_cq(struct ib_uverbs_file *file,
if (ret)
return ret;
ib_rdmacg_uncharge(&uobj->cg_obj, ib_dev, RDMACG_RESOURCE_HCA_OBJECT);
idr_remove_uobj(&ib_uverbs_cq_idr, uobj);
mutex_lock(&file->mutex);
@ -1904,6 +1953,11 @@ static int create_qp(struct ib_uverbs_file *file,
goto err_put;
}
ret = ib_rdmacg_try_charge(&obj->uevent.uobject.cg_obj, device,
RDMACG_RESOURCE_HCA_OBJECT);
if (ret)
goto err_put;
if (cmd->qp_type == IB_QPT_XRC_TGT)
qp = ib_create_qp(pd, &attr);
else
@ -1911,7 +1965,7 @@ static int create_qp(struct ib_uverbs_file *file,
if (IS_ERR(qp)) {
ret = PTR_ERR(qp);
goto err_put;
goto err_create;
}
if (cmd->qp_type != IB_QPT_XRC_TGT) {
@ -1992,6 +2046,10 @@ err_cb:
err_destroy:
ib_destroy_qp(qp);
err_create:
ib_rdmacg_uncharge(&obj->uevent.uobject.cg_obj, device,
RDMACG_RESOURCE_HCA_OBJECT);
err_put:
if (xrcd)
put_xrcd_read(xrcd_uobj);
@ -2518,6 +2576,8 @@ ssize_t ib_uverbs_destroy_qp(struct ib_uverbs_file *file,
if (ret)
return ret;
ib_rdmacg_uncharge(&uobj->cg_obj, ib_dev, RDMACG_RESOURCE_HCA_OBJECT);
if (obj->uxrcd)
atomic_dec(&obj->uxrcd->refcnt);
@ -2969,11 +3029,16 @@ ssize_t ib_uverbs_create_ah(struct ib_uverbs_file *file,
memset(&attr.dmac, 0, sizeof(attr.dmac));
memcpy(attr.grh.dgid.raw, cmd.attr.grh.dgid, 16);
ret = ib_rdmacg_try_charge(&uobj->cg_obj, ib_dev,
RDMACG_RESOURCE_HCA_OBJECT);
if (ret)
goto err_charge;
ah = pd->device->create_ah(pd, &attr, &udata);
if (IS_ERR(ah)) {
ret = PTR_ERR(ah);
goto err_put;
goto err_create;
}
ah->device = pd->device;
@ -3012,7 +3077,10 @@ err_copy:
err_destroy:
ib_destroy_ah(ah);
err_put:
err_create:
ib_rdmacg_uncharge(&uobj->cg_obj, ib_dev, RDMACG_RESOURCE_HCA_OBJECT);
err_charge:
put_pd_read(pd);
err:
@ -3046,6 +3114,8 @@ ssize_t ib_uverbs_destroy_ah(struct ib_uverbs_file *file,
if (ret)
return ret;
ib_rdmacg_uncharge(&uobj->cg_obj, ib_dev, RDMACG_RESOURCE_HCA_OBJECT);
idr_remove_uobj(&ib_uverbs_ah_idr, uobj);
mutex_lock(&file->mutex);
@ -3822,10 +3892,16 @@ int ib_uverbs_ex_create_flow(struct ib_uverbs_file *file,
err = -EINVAL;
goto err_free;
}
err = ib_rdmacg_try_charge(&uobj->cg_obj, ib_dev,
RDMACG_RESOURCE_HCA_OBJECT);
if (err)
goto err_free;
flow_id = ib_create_flow(qp, flow_attr, IB_FLOW_DOMAIN_USER);
if (IS_ERR(flow_id)) {
err = PTR_ERR(flow_id);
goto err_free;
goto err_create;
}
flow_id->uobject = uobj;
uobj->object = flow_id;
@ -3858,6 +3934,8 @@ err_copy:
idr_remove_uobj(&ib_uverbs_rule_idr, uobj);
destroy_flow:
ib_destroy_flow(flow_id);
err_create:
ib_rdmacg_uncharge(&uobj->cg_obj, ib_dev, RDMACG_RESOURCE_HCA_OBJECT);
err_free:
kfree(flow_attr);
err_put:
@ -3897,8 +3975,11 @@ int ib_uverbs_ex_destroy_flow(struct ib_uverbs_file *file,
flow_id = uobj->object;
ret = ib_destroy_flow(flow_id);
if (!ret)
if (!ret) {
ib_rdmacg_uncharge(&uobj->cg_obj, ib_dev,
RDMACG_RESOURCE_HCA_OBJECT);
uobj->live = 0;
}
put_uobj_write(uobj);
@ -3966,6 +4047,11 @@ static int __uverbs_create_xsrq(struct ib_uverbs_file *file,
obj->uevent.events_reported = 0;
INIT_LIST_HEAD(&obj->uevent.event_list);
ret = ib_rdmacg_try_charge(&obj->uevent.uobject.cg_obj, ib_dev,
RDMACG_RESOURCE_HCA_OBJECT);
if (ret)
goto err_put_cq;
srq = pd->device->create_srq(pd, &attr, udata);
if (IS_ERR(srq)) {
ret = PTR_ERR(srq);
@ -4030,6 +4116,8 @@ err_destroy:
ib_destroy_srq(srq);
err_put:
ib_rdmacg_uncharge(&obj->uevent.uobject.cg_obj, ib_dev,
RDMACG_RESOURCE_HCA_OBJECT);
put_pd_read(pd);
err_put_cq:
@ -4216,6 +4304,8 @@ ssize_t ib_uverbs_destroy_srq(struct ib_uverbs_file *file,
if (ret)
return ret;
ib_rdmacg_uncharge(&uobj->cg_obj, ib_dev, RDMACG_RESOURCE_HCA_OBJECT);
if (srq_type == IB_SRQT_XRC) {
us = container_of(obj, struct ib_usrq_object, uevent);
atomic_dec(&us->uxrcd->refcnt);

20
drivers/infiniband/core/uverbs_main.c
View file

@ -51,6 +51,7 @@
#include <rdma/ib.h>
#include "uverbs.h"
#include "core_priv.h"
MODULE_AUTHOR("Roland Dreier");
MODULE_DESCRIPTION("InfiniBand userspace verbs access");
@ -237,6 +238,8 @@ static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
idr_remove_uobj(&ib_uverbs_ah_idr, uobj);
ib_destroy_ah(ah);
ib_rdmacg_uncharge(&uobj->cg_obj, context->device,
RDMACG_RESOURCE_HCA_OBJECT);
kfree(uobj);
}
@ -246,6 +249,8 @@ static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
idr_remove_uobj(&ib_uverbs_mw_idr, uobj);
uverbs_dealloc_mw(mw);
ib_rdmacg_uncharge(&uobj->cg_obj, context->device,
RDMACG_RESOURCE_HCA_OBJECT);
kfree(uobj);
}
@ -254,6 +259,8 @@ static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
idr_remove_uobj(&ib_uverbs_rule_idr, uobj);
ib_destroy_flow(flow_id);
ib_rdmacg_uncharge(&uobj->cg_obj, context->device,
RDMACG_RESOURCE_HCA_OBJECT);
kfree(uobj);
}
@ -266,6 +273,8 @@ static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
if (qp == qp->real_qp)
ib_uverbs_detach_umcast(qp, uqp);
ib_destroy_qp(qp);
ib_rdmacg_uncharge(&uobj->cg_obj, context->device,
RDMACG_RESOURCE_HCA_OBJECT);
ib_uverbs_release_uevent(file, &uqp->uevent);
kfree(uqp);
}
@ -298,6 +307,8 @@ static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
idr_remove_uobj(&ib_uverbs_srq_idr, uobj);
ib_destroy_srq(srq);
ib_rdmacg_uncharge(&uobj->cg_obj, context->device,
RDMACG_RESOURCE_HCA_OBJECT);
ib_uverbs_release_uevent(file, uevent);
kfree(uevent);
}
@ -310,6 +321,8 @@ static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
idr_remove_uobj(&ib_uverbs_cq_idr, uobj);
ib_destroy_cq(cq);
ib_rdmacg_uncharge(&uobj->cg_obj, context->device,
RDMACG_RESOURCE_HCA_OBJECT);
ib_uverbs_release_ucq(file, ev_file, ucq);
kfree(ucq);
}
@ -319,6 +332,8 @@ static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
idr_remove_uobj(&ib_uverbs_mr_idr, uobj);
ib_dereg_mr(mr);
ib_rdmacg_uncharge(&uobj->cg_obj, context->device,
RDMACG_RESOURCE_HCA_OBJECT);
kfree(uobj);
}
@ -339,11 +354,16 @@ static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
idr_remove_uobj(&ib_uverbs_pd_idr, uobj);
ib_dealloc_pd(pd);
ib_rdmacg_uncharge(&uobj->cg_obj, context->device,
RDMACG_RESOURCE_HCA_OBJECT);
kfree(uobj);
}
put_pid(context->tgid);
ib_rdmacg_uncharge(&context->cg_obj, context->device,
RDMACG_RESOURCE_HCA_HANDLE);
return context->device->dealloc_ucontext(context);
}

53
include/linux/cgroup_rdma.h Normal file
View file

@ -0,0 +1,53 @@
/*
* Copyright (C) 2016 Parav Pandit <pandit.parav@gmail.com>
*
* This file is subject to the terms and conditions of version 2 of the GNU
* General Public License. See the file COPYING in the main directory of the
* Linux distribution for more details.
*/
#ifndef _CGROUP_RDMA_H
#define _CGROUP_RDMA_H
#include <linux/cgroup.h>
enum rdmacg_resource_type {
RDMACG_RESOURCE_HCA_HANDLE,
RDMACG_RESOURCE_HCA_OBJECT,
RDMACG_RESOURCE_MAX,
};
#ifdef CONFIG_CGROUP_RDMA
struct rdma_cgroup {
struct cgroup_subsys_state css;
/*
* head to keep track of all resource pools
* that belongs to this cgroup.
*/
struct list_head rpools;
};
struct rdmacg_device {
struct list_head dev_node;
struct list_head rpools;
char *name;
};
/*
* APIs for RDMA/IB stack to publish when a device wants to
* participate in resource accounting
*/
int rdmacg_register_device(struct rdmacg_device *device);
void rdmacg_unregister_device(struct rdmacg_device *device);
/* APIs for RDMA/IB stack to charge/uncharge pool specific resources */
int rdmacg_try_charge(struct rdma_cgroup **rdmacg,
struct rdmacg_device *device,
enum rdmacg_resource_type index);
void rdmacg_uncharge(struct rdma_cgroup *cg,
struct rdmacg_device *device,
enum rdmacg_resource_type index);
#endif /* CONFIG_CGROUP_RDMA */
#endif /* _CGROUP_RDMA_H */

4
include/linux/cgroup_subsys.h
View file

@ -56,6 +56,10 @@ SUBSYS(hugetlb)
SUBSYS(pids)
#endif
#if IS_ENABLED(CONFIG_CGROUP_RDMA)
SUBSYS(rdma)
#endif
/*
* The following subsystems are not supported on the default hierarchy.
*/

14
include/rdma/ib_verbs.h
View file

@ -60,6 +60,7 @@
#include <linux/atomic.h>
#include <linux/mmu_notifier.h>
#include <linux/uaccess.h>
#include <linux/cgroup_rdma.h>
extern struct workqueue_struct *ib_wq;
extern struct workqueue_struct *ib_comp_wq;
@ -1331,6 +1332,12 @@ struct ib_fmr_attr {
struct ib_umem;
struct ib_rdmacg_object {
#ifdef CONFIG_CGROUP_RDMA
struct rdma_cgroup *cg; /* owner rdma cgroup */
#endif
};
struct ib_ucontext {
struct ib_device *device;
struct list_head pd_list;
@ -1363,6 +1370,8 @@ struct ib_ucontext {
struct list_head no_private_counters;
int odp_mrs_count;
#endif
struct ib_rdmacg_object cg_obj;
};
struct ib_uobject {
@ -1370,6 +1379,7 @@ struct ib_uobject {
struct ib_ucontext *context; /* associated user context */
void *object; /* containing object */
struct list_head list; /* link to context's list */
struct ib_rdmacg_object cg_obj; /* rdmacg object */
int id; /* index into kernel idr */
struct kref ref;
struct rw_semaphore mutex; /* protects .live */
@ -2118,6 +2128,10 @@ struct ib_device {
struct attribute_group *hw_stats_ag;
struct rdma_hw_stats *hw_stats;
#ifdef CONFIG_CGROUP_RDMA
struct rdmacg_device cg_device;
#endif
/**
* The following mandatory functions are used only at device
* registration. Keep functions such as these at the end of this

10
init/Kconfig
View file

@ -1090,6 +1090,16 @@ config CGROUP_PIDS
since the PIDs limit only affects a process's ability to fork, not to
attach to a cgroup.
config CGROUP_RDMA
bool "RDMA controller"
help
Provides enforcement of RDMA resources defined by IB stack.
It is fairly easy for consumers to exhaust RDMA resources, which
can result into resource unavailability to other consumers.
RDMA controller is designed to stop this from happening.
Attaching processes with active RDMA resources to the cgroup
hierarchy is allowed even if can cross the hierarchy's limit.
config CGROUP_FREEZER
bool "Freezer controller"
help

1
kernel/cgroup/Makefile
View file

@ -2,4 +2,5 @@ obj-y := cgroup.o namespace.o cgroup-v1.o
obj-$(CONFIG_CGROUP_FREEZER) += freezer.o
obj-$(CONFIG_CGROUP_PIDS) += pids.o
obj-$(CONFIG_CGROUP_RDMA) += rdma.o
obj-$(CONFIG_CPUSETS) += cpuset.o

619
kernel/cgroup/rdma.c Normal file
View file

@ -0,0 +1,619 @@
/*
* RDMA resource limiting controller for cgroups.
*
* Used to allow a cgroup hierarchy to stop processes from consuming
* additional RDMA resources after a certain limit is reached.
*
* Copyright (C) 2016 Parav Pandit <pandit.parav@gmail.com>
*
* This file is subject to the terms and conditions of version 2 of the GNU
* General Public License. See the file COPYING in the main directory of the
* Linux distribution for more details.
*/
#include <linux/bitops.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
#include <linux/cgroup.h>
#include <linux/parser.h>
#include <linux/cgroup_rdma.h>
#define RDMACG_MAX_STR "max"
/*
* Protects list of resource pools maintained on per cgroup basis
* and rdma device list.
*/
static DEFINE_MUTEX(rdmacg_mutex);
static LIST_HEAD(rdmacg_devices);
enum rdmacg_file_type {
RDMACG_RESOURCE_TYPE_MAX,
RDMACG_RESOURCE_TYPE_STAT,
};
/*
* resource table definition as to be seen by the user.
* Need to add entries to it when more resources are
* added/defined at IB verb/core layer.
*/
static char const *rdmacg_resource_names[] = {
[RDMACG_RESOURCE_HCA_HANDLE] = "hca_handle",
[RDMACG_RESOURCE_HCA_OBJECT] = "hca_object",
};
/* resource tracker for each resource of rdma cgroup */
struct rdmacg_resource {
int max;
int usage;
};
/*
* resource pool object which represents per cgroup, per device
* resources. There are multiple instances of this object per cgroup,
* therefore it cannot be embedded within rdma_cgroup structure. It
* is maintained as list.
*/
struct rdmacg_resource_pool {
struct rdmacg_device *device;
struct rdmacg_resource resources[RDMACG_RESOURCE_MAX];
struct list_head cg_node;
struct list_head dev_node;
/* count active user tasks of this pool */
u64 usage_sum;
/* total number counts which are set to max */
int num_max_cnt;
};
static struct rdma_cgroup *css_rdmacg(struct cgroup_subsys_state *css)
{
return container_of(css, struct rdma_cgroup, css);
}
static struct rdma_cgroup *parent_rdmacg(struct rdma_cgroup *cg)
{
return css_rdmacg(cg->css.parent);
}
static inline struct rdma_cgroup *get_current_rdmacg(void)
{
return css_rdmacg(task_get_css(current, rdma_cgrp_id));
}
static void set_resource_limit(struct rdmacg_resource_pool *rpool,
int index, int new_max)
{
if (new_max == S32_MAX) {
if (rpool->resources[index].max != S32_MAX)
rpool->num_max_cnt++;
} else {
if (rpool->resources[index].max == S32_MAX)
rpool->num_max_cnt--;
}
rpool->resources[index].max = new_max;
}
static void set_all_resource_max_limit(struct rdmacg_resource_pool *rpool)
{
int i;
for (i = 0; i < RDMACG_RESOURCE_MAX; i++)
set_resource_limit(rpool, i, S32_MAX);
}
static void free_cg_rpool_locked(struct rdmacg_resource_pool *rpool)
{
lockdep_assert_held(&rdmacg_mutex);
list_del(&rpool->cg_node);
list_del(&rpool->dev_node);
kfree(rpool);
}
static struct rdmacg_resource_pool *
find_cg_rpool_locked(struct rdma_cgroup *cg,
struct rdmacg_device *device)
{
struct rdmacg_resource_pool *pool;
lockdep_assert_held(&rdmacg_mutex);
list_for_each_entry(pool, &cg->rpools, cg_node)
if (pool->device == device)
return pool;
return NULL;
}
static struct rdmacg_resource_pool *
get_cg_rpool_locked(struct rdma_cgroup *cg, struct rdmacg_device *device)
{
struct rdmacg_resource_pool *rpool;
rpool = find_cg_rpool_locked(cg, device);
if (rpool)
return rpool;
rpool = kzalloc(sizeof(*rpool), GFP_KERNEL);
if (!rpool)
return ERR_PTR(-ENOMEM);
rpool->device = device;
set_all_resource_max_limit(rpool);
INIT_LIST_HEAD(&rpool->cg_node);
INIT_LIST_HEAD(&rpool->dev_node);
list_add_tail(&rpool->cg_node, &cg->rpools);
list_add_tail(&rpool->dev_node, &device->rpools);
return rpool;
}
/**
* uncharge_cg_locked - uncharge resource for rdma cgroup
* @cg: pointer to cg to uncharge and all parents in hierarchy
* @device: pointer to rdmacg device
* @index: index of the resource to uncharge in cg (resource pool)
*
* It also frees the resource pool which was created as part of
* charging operation when there are no resources attached to
* resource pool.
*/
static void
uncharge_cg_locked(struct rdma_cgroup *cg,
struct rdmacg_device *device,
enum rdmacg_resource_type index)
{
struct rdmacg_resource_pool *rpool;
rpool = find_cg_rpool_locked(cg, device);
/*
* rpool cannot be null at this stage. Let kernel operate in case
* if there a bug in IB stack or rdma controller, instead of crashing
* the system.
*/
if (unlikely(!rpool)) {
pr_warn("Invalid device %p or rdma cgroup %p\n", cg, device);
return;
}
rpool->resources[index].usage--;
/*
* A negative count (or overflow) is invalid,
* it indicates a bug in the rdma controller.
*/
WARN_ON_ONCE(rpool->resources[index].usage < 0);
rpool->usage_sum--;
if (rpool->usage_sum == 0 &&
rpool->num_max_cnt == RDMACG_RESOURCE_MAX) {
/*
* No user of the rpool and all entries are set to max, so
* safe to delete this rpool.
*/
free_cg_rpool_locked(rpool);
}
}
/**
* rdmacg_uncharge_hierarchy - hierarchically uncharge rdma resource count
* @device: pointer to rdmacg device
* @stop_cg: while traversing hirerchy, when meet with stop_cg cgroup
* stop uncharging
* @index: index of the resource to uncharge in cg in given resource pool
*/
static void rdmacg_uncharge_hierarchy(struct rdma_cgroup *cg,
struct rdmacg_device *device,
struct rdma_cgroup *stop_cg,
enum rdmacg_resource_type index)
{
struct rdma_cgroup *p;
mutex_lock(&rdmacg_mutex);
for (p = cg; p != stop_cg; p = parent_rdmacg(p))
uncharge_cg_locked(p, device, index);
mutex_unlock(&rdmacg_mutex);
css_put(&cg->css);
}
/**
* rdmacg_uncharge - hierarchically uncharge rdma resource count
* @device: pointer to rdmacg device
* @index: index of the resource to uncharge in cgroup in given resource pool
*/
void rdmacg_uncharge(struct rdma_cgroup *cg,
struct rdmacg_device *device,
enum rdmacg_resource_type index)
{
if (index >= RDMACG_RESOURCE_MAX)
return;
rdmacg_uncharge_hierarchy(cg, device, NULL, index);
}
EXPORT_SYMBOL(rdmacg_uncharge);
/**
* rdmacg_try_charge - hierarchically try to charge the rdma resource
* @rdmacg: pointer to rdma cgroup which will own this resource
* @device: pointer to rdmacg device
* @index: index of the resource to charge in cgroup (resource pool)
*
* This function follows charging resource in hierarchical way.
* It will fail if the charge would cause the new value to exceed the
* hierarchical limit.
* Returns 0 if the charge succeded, otherwise -EAGAIN, -ENOMEM or -EINVAL.
* Returns pointer to rdmacg for this resource when charging is successful.
*
* Charger needs to account resources on two criteria.
* (a) per cgroup & (b) per device resource usage.
* Per cgroup resource usage ensures that tasks of cgroup doesn't cross
* the configured limits. Per device provides granular configuration
* in multi device usage. It allocates resource pool in the hierarchy
* for each parent it come across for first resource. Later on resource
* pool will be available. Therefore it will be much faster thereon
* to charge/uncharge.
*/
int rdmacg_try_charge(struct rdma_cgroup **rdmacg,
struct rdmacg_device *device,
enum rdmacg_resource_type index)
{
struct rdma_cgroup *cg, *p;
struct rdmacg_resource_pool *rpool;
s64 new;
int ret = 0;
if (index >= RDMACG_RESOURCE_MAX)
return -EINVAL;
/*
* hold on to css, as cgroup can be removed but resource
* accounting happens on css.
*/
cg = get_current_rdmacg();
mutex_lock(&rdmacg_mutex);
for (p = cg; p; p = parent_rdmacg(p)) {
rpool = get_cg_rpool_locked(p, device);
if (IS_ERR(rpool)) {
ret = PTR_ERR(rpool);
goto err;
} else {
new = rpool->resources[index].usage + 1;
if (new > rpool->resources[index].max) {
ret = -EAGAIN;
goto err;
} else {
rpool->resources[index].usage = new;
rpool->usage_sum++;
}
}
}
mutex_unlock(&rdmacg_mutex);
*rdmacg = cg;
return 0;
err:
mutex_unlock(&rdmacg_mutex);
rdmacg_uncharge_hierarchy(cg, device, p, index);
return ret;
}
EXPORT_SYMBOL(rdmacg_try_charge);
/**
* rdmacg_register_device - register rdmacg device to rdma controller.
* @device: pointer to rdmacg device whose resources need to be accounted.
*
* If IB stack wish a device to participate in rdma cgroup resource
* tracking, it must invoke this API to register with rdma cgroup before
* any user space application can start using the RDMA resources.
* Returns 0 on success or EINVAL when table length given is beyond
* supported size.
*/
int rdmacg_register_device(struct rdmacg_device *device)
{
INIT_LIST_HEAD(&device->dev_node);
INIT_LIST_HEAD(&device->rpools);
mutex_lock(&rdmacg_mutex);
list_add_tail(&device->dev_node, &rdmacg_devices);
mutex_unlock(&rdmacg_mutex);
return 0;
}
EXPORT_SYMBOL(rdmacg_register_device);
/**
* rdmacg_unregister_device - unregister rdmacg device from rdma controller.
* @device: pointer to rdmacg device which was previously registered with rdma
* controller using rdmacg_register_device().
*
* IB stack must invoke this after all the resources of the IB device
* are destroyed and after ensuring that no more resources will be created
* when this API is invoked.
*/
void rdmacg_unregister_device(struct rdmacg_device *device)
{
struct rdmacg_resource_pool *rpool, *tmp;
/*
* Synchronize with any active resource settings,
* usage query happening via configfs.
*/
mutex_lock(&rdmacg_mutex);
list_del_init(&device->dev_node);
/*
* Now that this device is off the cgroup list, its safe to free
* all the rpool resources.
*/
list_for_each_entry_safe(rpool, tmp, &device->rpools, dev_node)
free_cg_rpool_locked(rpool);
mutex_unlock(&rdmacg_mutex);
}
EXPORT_SYMBOL(rdmacg_unregister_device);
static int parse_resource(char *c, int *intval)
{
substring_t argstr;
const char **table = &rdmacg_resource_names[0];
char *name, *value = c;
size_t len;
int ret, i = 0;
name = strsep(&value, "=");
if (!name || !value)
return -EINVAL;
len = strlen(value);
for (i = 0; i < RDMACG_RESOURCE_MAX; i++) {
if (strcmp(table[i], name))
continue;
argstr.from = value;
argstr.to = value + len;
ret = match_int(&argstr, intval);
if (ret >= 0) {
if (*intval < 0)
break;
return i;
}
if (strncmp(value, RDMACG_MAX_STR, len) == 0) {
*intval = S32_MAX;
return i;
}
break;
}
return -EINVAL;
}
static int rdmacg_parse_limits(char *options,
int *new_limits, unsigned long *enables)
{
char *c;
int err = -EINVAL;
/* parse resource options */
while ((c = strsep(&options, " ")) != NULL) {
int index, intval;
index = parse_resource(c, &intval);
if (index < 0)
goto err;
new_limits[index] = intval;
*enables |= BIT(index);
}
return 0;
err:
return err;
}
static struct rdmacg_device *rdmacg_get_device_locked(const char *name)
{
struct rdmacg_device *device;
lockdep_assert_held(&rdmacg_mutex);
list_for_each_entry(device, &rdmacg_devices, dev_node)
if (!strcmp(name, device->name))
return device;
return NULL;
}
static ssize_t rdmacg_resource_set_max(struct kernfs_open_file *of,
char *buf, size_t nbytes, loff_t off)
{
struct rdma_cgroup *cg = css_rdmacg(of_css(of));
const char *dev_name;
struct rdmacg_resource_pool *rpool;
struct rdmacg_device *device;
char *options = strstrip(buf);
int *new_limits;
unsigned long enables = 0;
int i = 0, ret = 0;
/* extract the device name first */
dev_name = strsep(&options, " ");
if (!dev_name) {
ret = -EINVAL;
goto err;
}
new_limits = kcalloc(RDMACG_RESOURCE_MAX, sizeof(int), GFP_KERNEL);
if (!new_limits) {
ret = -ENOMEM;
goto err;
}
ret = rdmacg_parse_limits(options, new_limits, &enables);
if (ret)
goto parse_err;
/* acquire lock to synchronize with hot plug devices */
mutex_lock(&rdmacg_mutex);
device = rdmacg_get_device_locked(dev_name);
if (!device) {
ret = -ENODEV;
goto dev_err;
}
rpool = get_cg_rpool_locked(cg, device);
if (IS_ERR(rpool)) {
ret = PTR_ERR(rpool);
goto dev_err;
}
/* now set the new limits of the rpool */
for_each_set_bit(i, &enables, RDMACG_RESOURCE_MAX)
set_resource_limit(rpool, i, new_limits[i]);
if (rpool->usage_sum == 0 &&
rpool->num_max_cnt == RDMACG_RESOURCE_MAX) {
/*
* No user of the rpool and all entries are set to max, so
* safe to delete this rpool.
*/
free_cg_rpool_locked(rpool);
}
dev_err:
mutex_unlock(&rdmacg_mutex);
parse_err:
kfree(new_limits);
err:
return ret ?: nbytes;
}
static void print_rpool_values(struct seq_file *sf,
struct rdmacg_resource_pool *rpool)
{
enum rdmacg_file_type sf_type;
int i;
u32 value;
sf_type = seq_cft(sf)->private;
for (i = 0; i < RDMACG_RESOURCE_MAX; i++) {
seq_puts(sf, rdmacg_resource_names[i]);
seq_putc(sf, '=');
if (sf_type == RDMACG_RESOURCE_TYPE_MAX) {
if (rpool)
value = rpool->resources[i].max;
else
value = S32_MAX;
} else {
if (rpool)
value = rpool->resources[i].usage;
else
value = 0;
}
if (value == S32_MAX)
seq_puts(sf, RDMACG_MAX_STR);
else
seq_printf(sf, "%d", value);
seq_putc(sf, ' ');
}
}
static int rdmacg_resource_read(struct seq_file *sf, void *v)
{
struct rdmacg_device *device;
struct rdmacg_resource_pool *rpool;
struct rdma_cgroup *cg = css_rdmacg(seq_css(sf));
mutex_lock(&rdmacg_mutex);
list_for_each_entry(device, &rdmacg_devices, dev_node) {
seq_printf(sf, "%s ", device->name);
rpool = find_cg_rpool_locked(cg, device);
print_rpool_values(sf, rpool);
seq_putc(sf, '\n');
}
mutex_unlock(&rdmacg_mutex);
return 0;
}
static struct cftype rdmacg_files[] = {
{
.name = "max",
.write = rdmacg_resource_set_max,
.seq_show = rdmacg_resource_read,
.private = RDMACG_RESOURCE_TYPE_MAX,
.flags = CFTYPE_NOT_ON_ROOT,
},
{
.name = "current",
.seq_show = rdmacg_resource_read,
.private = RDMACG_RESOURCE_TYPE_STAT,
.flags = CFTYPE_NOT_ON_ROOT,
},
{ } /* terminate */
};
static struct cgroup_subsys_state *
rdmacg_css_alloc(struct cgroup_subsys_state *parent)
{
struct rdma_cgroup *cg;
cg = kzalloc(sizeof(*cg), GFP_KERNEL);
if (!cg)
return ERR_PTR(-ENOMEM);
INIT_LIST_HEAD(&cg->rpools);
return &cg->css;
}
static void rdmacg_css_free(struct cgroup_subsys_state *css)
{
struct rdma_cgroup *cg = css_rdmacg(css);
kfree(cg);
}
/**
* rdmacg_css_offline - cgroup css_offline callback
* @css: css of interest
*
* This function is called when @css is about to go away and responsible
* for shooting down all rdmacg associated with @css. As part of that it
* marks all the resource pool entries to max value, so that when resources are
* uncharged, associated resource pool can be freed as well.
*/
static void rdmacg_css_offline(struct cgroup_subsys_state *css)
{
struct rdma_cgroup *cg = css_rdmacg(css);
struct rdmacg_resource_pool *rpool;
mutex_lock(&rdmacg_mutex);
list_for_each_entry(rpool, &cg->rpools, cg_node)
set_all_resource_max_limit(rpool);
mutex_unlock(&rdmacg_mutex);
}
struct cgroup_subsys rdma_cgrp_subsys = {
.css_alloc = rdmacg_css_alloc,
.css_free = rdmacg_css_free,
.css_offline = rdmacg_css_offline,
.legacy_cftypes = rdmacg_files,
.dfl_cftypes = rdmacg_files,
};