--- /dev/null
+ 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
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
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
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
--- /dev/null
+/*
+ * 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);
#include <linux/list.h>
#include <linux/spinlock.h>
+#include <linux/cgroup_rdma.h>
#include <rdma/ib_verbs.h>
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)
{
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;
}
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;
}
mutex_unlock(&device_mutex);
+ ib_device_unregister_rdmacg(device);
ib_device_unregister_sysfs(device);
ib_cache_cleanup_one(device);
struct ib_udata udata;
struct ib_ucontext *ucontext;
struct file *filp;
+ struct ib_rdmacg_object cg_obj;
int ret;
if (out_len < sizeof resp)
(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);
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;
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);
ib_dealloc_pd(pd);
err:
+ ib_rdmacg_uncharge(&uobj->cg_obj, ib_dev, RDMACG_RESOURCE_HCA_OBJECT);
put_uobj_write(uobj);
return ret;
}
if (ret)
goto err_put;
+ ib_rdmacg_uncharge(&uobj->cg_obj, ib_dev, RDMACG_RESOURCE_HCA_OBJECT);
+
uobj->live = 0;
put_uobj_write(uobj);
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);
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:
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);
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);
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:
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);
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)) {
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);
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);
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
if (IS_ERR(qp)) {
ret = PTR_ERR(qp);
- goto err_put;
+ goto err_create;
}
if (cmd->qp_type != IB_QPT_XRC_TGT) {
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);
if (ret)
return ret;
+ ib_rdmacg_uncharge(&uobj->cg_obj, ib_dev, RDMACG_RESOURCE_HCA_OBJECT);
+
if (obj->uxrcd)
atomic_dec(&obj->uxrcd->refcnt);
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;
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:
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);
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;
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:
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);
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);
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:
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);
#include <rdma/ib.h>
#include "uverbs.h"
+#include "core_priv.h"
MODULE_AUTHOR("Roland Dreier");
MODULE_DESCRIPTION("InfiniBand userspace verbs access");
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);
}
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);
}
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);
}
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);
}
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);
}
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);
}
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);
}
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);
}
--- /dev/null
+/*
+ * 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 */
SUBSYS(pids)
#endif
+#if IS_ENABLED(CONFIG_CGROUP_RDMA)
+SUBSYS(rdma)
+#endif
+
/*
* The following subsystems are not supported on the default hierarchy.
*/
#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;
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;
struct list_head no_private_counters;
int odp_mrs_count;
#endif
+
+ struct ib_rdmacg_object cg_obj;
};
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 */
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
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
obj-$(CONFIG_CGROUP_FREEZER) += freezer.o
obj-$(CONFIG_CGROUP_PIDS) += pids.o
+obj-$(CONFIG_CGROUP_RDMA) += rdma.o
obj-$(CONFIG_CPUSETS) += cpuset.o
--- /dev/null
+/*
+ * 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,
+};
projects / mirror_ubuntu-artful-kernel.git / commitdiff