From: Haggai Eran <haggaie@mellanox.com>
To: Parav Pandit <pandit.parav@gmail.com>, <cgroups@vger.kernel.org>,
<linux-doc@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<linux-rdma@vger.kernel.org>, <tj@kernel.org>,
<lizefan@huawei.com>, <hannes@cmpxchg.org>, <dledford@redhat.com>
Cc: <corbet@lwn.net>, <james.l.morris@oracle.com>, <serge@hallyn.com>,
<ogerlitz@mellanox.com>, <matanb@mellanox.com>,
<raindel@mellanox.com>, <akpm@linux-foundation.org>,
<linux-security-module@vger.kernel.org>
Subject: Re: [PATCH 5/7] devcg: device cgroup's extension for RDMA resource.
Date: Tue, 8 Sep 2015 11:22:56 +0300 [thread overview]
Message-ID: <55EE9AE0.5030508@mellanox.com> (raw)
In-Reply-To: <1441658303-18081-6-git-send-email-pandit.parav@gmail.com>
On 07/09/2015 23:38, Parav Pandit wrote:
> +/* RDMA resources from device cgroup perspective */
> +enum devcgroup_rdma_rt {
> + DEVCG_RDMA_RES_TYPE_UCTX,
> + DEVCG_RDMA_RES_TYPE_CQ,
> + DEVCG_RDMA_RES_TYPE_PD,
> + DEVCG_RDMA_RES_TYPE_AH,
> + DEVCG_RDMA_RES_TYPE_MR,
> + DEVCG_RDMA_RES_TYPE_MW,
I didn't see memory windows in dev_cgroup_files in patch 3. Is it used?
> + DEVCG_RDMA_RES_TYPE_SRQ,
> + DEVCG_RDMA_RES_TYPE_QP,
> + DEVCG_RDMA_RES_TYPE_FLOW,
> + DEVCG_RDMA_RES_TYPE_MAX,
> +};
> +struct devcgroup_rdma_tracker {
> + int limit;
> + atomic_t usage;
> + int failcnt;
> +};
Have you considered using struct res_counter?
> + * RDMA resource limits are hierarchical, so the highest configured limit of
> + * the hierarchy is enforced. Allowing resource limit configuration to default
> + * cgroup allows fair share to kernel space ULPs as well.
In what way is the highest configured limit of the hierarchy enforced? I
would expect all the limits along the hierarchy to be enforced.
> +int devcgroup_rdma_get_max_resource(struct seq_file *sf, void *v)
> +{
> + struct dev_cgroup *dev_cg = css_to_devcgroup(seq_css(sf));
> + int type = seq_cft(sf)->private;
> + u32 usage;
> +
> + if (dev_cg->rdma.tracker[type].limit == DEVCG_RDMA_MAX_RESOURCES) {
> + seq_printf(sf, "%s\n", DEVCG_RDMA_MAX_RESOURCE_STR);
> + } else {
> + usage = dev_cg->rdma.tracker[type].limit;
If this is the resource limit, don't name it 'usage'.
> + seq_printf(sf, "%u\n", usage);
> + }
> + return 0;
> +}
> +int devcgroup_rdma_get_max_resource(struct seq_file *sf, void *v)
> +{
> + struct dev_cgroup *dev_cg = css_to_devcgroup(seq_css(sf));
> + int type = seq_cft(sf)->private;
> + u32 usage;
> +
> + if (dev_cg->rdma.tracker[type].limit == DEVCG_RDMA_MAX_RESOURCES) {
> + seq_printf(sf, "%s\n", DEVCG_RDMA_MAX_RESOURCE_STR);
I'm not sure hiding the actual number is good, especially in the
show_usage case.
> + } else {
> + usage = dev_cg->rdma.tracker[type].limit;
> + seq_printf(sf, "%u\n", usage);
> + }
> + return 0;
> +}
> +void devcgroup_rdma_uncharge_resource(struct ib_ucontext *ucontext,
> + enum devcgroup_rdma_rt type, int num)
> +{
> + struct dev_cgroup *dev_cg, *p;
> + struct task_struct *ctx_task;
> +
> + if (!num)
> + return;
> +
> + /* get cgroup of ib_ucontext it belong to, to uncharge
> + * so that when its called from any worker tasks or any
> + * other tasks to which this resource doesn't belong to,
> + * it can be uncharged correctly.
> + */
> + if (ucontext)
> + ctx_task = get_pid_task(ucontext->tgid, PIDTYPE_PID);
> + else
> + ctx_task = current;
> + dev_cg = task_devcgroup(ctx_task);
> +
> + spin_lock(&ctx_task->rdma_res_counter->lock);
Don't you need an rcu read lock and rcu_dereference to access
rdma_res_counter?
> + ctx_task->rdma_res_counter->usage[type] -= num;
> +
> + for (p = dev_cg; p; p = parent_devcgroup(p))
> + uncharge_resource(p, type, num);
> +
> + spin_unlock(&ctx_task->rdma_res_counter->lock);
> +
> + if (type == DEVCG_RDMA_RES_TYPE_UCTX)
> + rdma_free_res_counter(ctx_task);
> +}
> +EXPORT_SYMBOL(devcgroup_rdma_uncharge_resource);
> +int devcgroup_rdma_try_charge_resource(enum devcgroup_rdma_rt type, int num)
> +{
> + struct dev_cgroup *dev_cg = task_devcgroup(current);
> + struct task_rdma_res_counter *res_cnt = current->rdma_res_counter;
> + int status;
> +
> + if (!res_cnt) {
> + res_cnt = kzalloc(sizeof(*res_cnt), GFP_KERNEL);
> + if (!res_cnt)
> + return -ENOMEM;
> +
> + spin_lock_init(&res_cnt->lock);
> + rcu_assign_pointer(current->rdma_res_counter, res_cnt);
Don't you need the task lock to update rdma_res_counter here?
> + }
> +
> + /* synchronize with migration task by taking lock, to avoid
> + * race condition of performing cgroup resource migration
> + * in non atomic way with this task, which can leads to leaked
> + * resources in older cgroup.
> + */
> + spin_lock(&res_cnt->lock);
> + status = try_charge_resource(dev_cg, type, num);
> + if (status)
> + goto busy;
> +
> + /* single task updating its rdma resource usage, so atomic is
> + * not required.
> + */
> + current->rdma_res_counter->usage[type] += num;
> +
> +busy:
> + spin_unlock(&res_cnt->lock);
> + return status;
> +}
> +EXPORT_SYMBOL(devcgroup_rdma_try_charge_resource);
Regards,
Haggai
WARNING: multiple messages have this Message-ID (diff)
From: Haggai Eran <haggaie@mellanox.com>
To: Parav Pandit <pandit.parav@gmail.com>,
cgroups@vger.kernel.org, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org,
tj@kernel.org, lizefan@huawei.com, hannes@cmpxchg.org,
dledford@redhat.com
Cc: corbet@lwn.net, james.l.morris@oracle.com, serge@hallyn.com,
ogerlitz@mellanox.com, matanb@mellanox.com, raindel@mellanox.com,
akpm@linux-foundation.org, linux-security-module@vger.kernel.org
Subject: Re: [PATCH 5/7] devcg: device cgroup's extension for RDMA resource.
Date: Tue, 8 Sep 2015 11:22:56 +0300 [thread overview]
Message-ID: <55EE9AE0.5030508@mellanox.com> (raw)
In-Reply-To: <1441658303-18081-6-git-send-email-pandit.parav@gmail.com>
On 07/09/2015 23:38, Parav Pandit wrote:
> +/* RDMA resources from device cgroup perspective */
> +enum devcgroup_rdma_rt {
> + DEVCG_RDMA_RES_TYPE_UCTX,
> + DEVCG_RDMA_RES_TYPE_CQ,
> + DEVCG_RDMA_RES_TYPE_PD,
> + DEVCG_RDMA_RES_TYPE_AH,
> + DEVCG_RDMA_RES_TYPE_MR,
> + DEVCG_RDMA_RES_TYPE_MW,
I didn't see memory windows in dev_cgroup_files in patch 3. Is it used?
> + DEVCG_RDMA_RES_TYPE_SRQ,
> + DEVCG_RDMA_RES_TYPE_QP,
> + DEVCG_RDMA_RES_TYPE_FLOW,
> + DEVCG_RDMA_RES_TYPE_MAX,
> +};
> +struct devcgroup_rdma_tracker {
> + int limit;
> + atomic_t usage;
> + int failcnt;
> +};
Have you considered using struct res_counter?
> + * RDMA resource limits are hierarchical, so the highest configured limit of
> + * the hierarchy is enforced. Allowing resource limit configuration to default
> + * cgroup allows fair share to kernel space ULPs as well.
In what way is the highest configured limit of the hierarchy enforced? I
would expect all the limits along the hierarchy to be enforced.
> +int devcgroup_rdma_get_max_resource(struct seq_file *sf, void *v)
> +{
> + struct dev_cgroup *dev_cg = css_to_devcgroup(seq_css(sf));
> + int type = seq_cft(sf)->private;
> + u32 usage;
> +
> + if (dev_cg->rdma.tracker[type].limit == DEVCG_RDMA_MAX_RESOURCES) {
> + seq_printf(sf, "%s\n", DEVCG_RDMA_MAX_RESOURCE_STR);
> + } else {
> + usage = dev_cg->rdma.tracker[type].limit;
If this is the resource limit, don't name it 'usage'.
> + seq_printf(sf, "%u\n", usage);
> + }
> + return 0;
> +}
> +int devcgroup_rdma_get_max_resource(struct seq_file *sf, void *v)
> +{
> + struct dev_cgroup *dev_cg = css_to_devcgroup(seq_css(sf));
> + int type = seq_cft(sf)->private;
> + u32 usage;
> +
> + if (dev_cg->rdma.tracker[type].limit == DEVCG_RDMA_MAX_RESOURCES) {
> + seq_printf(sf, "%s\n", DEVCG_RDMA_MAX_RESOURCE_STR);
I'm not sure hiding the actual number is good, especially in the
show_usage case.
> + } else {
> + usage = dev_cg->rdma.tracker[type].limit;
> + seq_printf(sf, "%u\n", usage);
> + }
> + return 0;
> +}
> +void devcgroup_rdma_uncharge_resource(struct ib_ucontext *ucontext,
> + enum devcgroup_rdma_rt type, int num)
> +{
> + struct dev_cgroup *dev_cg, *p;
> + struct task_struct *ctx_task;
> +
> + if (!num)
> + return;
> +
> + /* get cgroup of ib_ucontext it belong to, to uncharge
> + * so that when its called from any worker tasks or any
> + * other tasks to which this resource doesn't belong to,
> + * it can be uncharged correctly.
> + */
> + if (ucontext)
> + ctx_task = get_pid_task(ucontext->tgid, PIDTYPE_PID);
> + else
> + ctx_task = current;
> + dev_cg = task_devcgroup(ctx_task);
> +
> + spin_lock(&ctx_task->rdma_res_counter->lock);
Don't you need an rcu read lock and rcu_dereference to access
rdma_res_counter?
> + ctx_task->rdma_res_counter->usage[type] -= num;
> +
> + for (p = dev_cg; p; p = parent_devcgroup(p))
> + uncharge_resource(p, type, num);
> +
> + spin_unlock(&ctx_task->rdma_res_counter->lock);
> +
> + if (type == DEVCG_RDMA_RES_TYPE_UCTX)
> + rdma_free_res_counter(ctx_task);
> +}
> +EXPORT_SYMBOL(devcgroup_rdma_uncharge_resource);
> +int devcgroup_rdma_try_charge_resource(enum devcgroup_rdma_rt type, int num)
> +{
> + struct dev_cgroup *dev_cg = task_devcgroup(current);
> + struct task_rdma_res_counter *res_cnt = current->rdma_res_counter;
> + int status;
> +
> + if (!res_cnt) {
> + res_cnt = kzalloc(sizeof(*res_cnt), GFP_KERNEL);
> + if (!res_cnt)
> + return -ENOMEM;
> +
> + spin_lock_init(&res_cnt->lock);
> + rcu_assign_pointer(current->rdma_res_counter, res_cnt);
Don't you need the task lock to update rdma_res_counter here?
> + }
> +
> + /* synchronize with migration task by taking lock, to avoid
> + * race condition of performing cgroup resource migration
> + * in non atomic way with this task, which can leads to leaked
> + * resources in older cgroup.
> + */
> + spin_lock(&res_cnt->lock);
> + status = try_charge_resource(dev_cg, type, num);
> + if (status)
> + goto busy;
> +
> + /* single task updating its rdma resource usage, so atomic is
> + * not required.
> + */
> + current->rdma_res_counter->usage[type] += num;
> +
> +busy:
> + spin_unlock(&res_cnt->lock);
> + return status;
> +}
> +EXPORT_SYMBOL(devcgroup_rdma_try_charge_resource);
Regards,
Haggai
next prev parent reply other threads:[~2015-09-08 8:22 UTC|newest]
Thread overview: 95+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-07 20:38 [PATCH 0/7] devcg: device cgroup extension for rdma resource Parav Pandit
2015-09-07 20:38 ` Parav Pandit
2015-09-07 20:38 ` [PATCH 1/7] devcg: Added user option to rdma resource tracking Parav Pandit
2015-09-07 20:38 ` Parav Pandit
2015-09-07 20:38 ` [PATCH 2/7] devcg: Added rdma resource tracking module Parav Pandit
2015-09-07 20:38 ` Parav Pandit
2015-09-07 20:38 ` [PATCH 3/7] devcg: Added infrastructure for rdma device cgroup Parav Pandit
2015-09-08 5:31 ` Haggai Eran
2015-09-08 5:31 ` Haggai Eran
2015-09-08 7:02 ` Parav Pandit
2015-09-08 7:02 ` Parav Pandit
2015-09-07 20:38 ` [PATCH 4/7] devcg: Added rdma resource tracker object per task Parav Pandit
2015-09-08 5:48 ` Haggai Eran
2015-09-08 5:48 ` Haggai Eran
2015-09-08 7:04 ` Parav Pandit
2015-09-08 8:24 ` Haggai Eran
2015-09-08 8:24 ` Haggai Eran
2015-09-08 8:26 ` Parav Pandit
2015-09-07 20:38 ` [PATCH 5/7] devcg: device cgroup's extension for RDMA resource Parav Pandit
2015-09-07 20:38 ` Parav Pandit
2015-09-08 8:22 ` Haggai Eran [this message]
2015-09-08 8:22 ` Haggai Eran
2015-09-08 10:18 ` Parav Pandit
2015-09-08 13:50 ` Haggai Eran
2015-09-08 13:50 ` Haggai Eran
2015-09-08 14:13 ` Parav Pandit
2015-09-08 8:36 ` Haggai Eran
2015-09-08 8:36 ` Haggai Eran
2015-09-08 10:50 ` Parav Pandit
2015-09-08 10:50 ` Parav Pandit
2015-09-08 14:10 ` Haggai Eran
2015-09-08 14:10 ` Haggai Eran
2015-09-07 20:38 ` [PATCH 6/7] devcg: Added support to use RDMA device cgroup Parav Pandit
2015-09-08 8:40 ` Haggai Eran
2015-09-08 8:40 ` Haggai Eran
2015-09-08 10:22 ` Parav Pandit
2015-09-08 13:40 ` Haggai Eran
2015-09-08 13:40 ` Haggai Eran
2015-09-07 20:38 ` [PATCH 7/7] devcg: Added Documentation of " Parav Pandit
2015-09-07 20:38 ` Parav Pandit
2015-09-07 20:55 ` [PATCH 0/7] devcg: device cgroup extension for rdma resource Parav Pandit
2015-09-08 12:45 ` Haggai Eran
2015-09-08 12:45 ` Haggai Eran
2015-09-08 15:23 ` Tejun Heo
2015-09-08 15:23 ` Tejun Heo
2015-09-09 3:57 ` Parav Pandit
2015-09-10 16:49 ` Tejun Heo
2015-09-10 17:46 ` Parav Pandit
2015-09-10 17:46 ` Parav Pandit
2015-09-10 20:22 ` Tejun Heo
2015-09-11 3:39 ` Parav Pandit
2015-09-11 4:04 ` Tejun Heo
2015-09-11 4:04 ` Tejun Heo
2015-09-11 4:24 ` Doug Ledford
2015-09-11 4:24 ` Doug Ledford
2015-09-11 14:52 ` Tejun Heo
2015-09-11 14:52 ` Tejun Heo
2015-09-11 16:26 ` Parav Pandit
2015-09-11 16:34 ` Tejun Heo
2015-09-11 16:34 ` Tejun Heo
2015-09-11 16:39 ` Parav Pandit
2015-09-11 16:39 ` Parav Pandit
2015-09-11 19:25 ` Tejun Heo
2015-09-14 10:18 ` Parav Pandit
2015-09-14 10:18 ` Parav Pandit
2015-09-11 16:47 ` Parav Pandit
2015-09-11 16:47 ` Parav Pandit
2015-09-11 19:05 ` Tejun Heo
2015-09-11 19:05 ` Tejun Heo
2015-09-11 19:22 ` Hefty, Sean
2015-09-11 19:43 ` Jason Gunthorpe
2015-09-11 19:43 ` Jason Gunthorpe
2015-09-11 20:06 ` Hefty, Sean
2015-09-14 11:09 ` Parav Pandit
2015-09-14 14:04 ` Parav Pandit
2015-09-14 15:21 ` Tejun Heo
2015-09-14 15:21 ` Tejun Heo
2015-09-14 17:28 ` Jason Gunthorpe
2015-09-14 17:28 ` Jason Gunthorpe
2015-09-14 18:54 ` Parav Pandit
2015-09-14 18:54 ` Parav Pandit
2015-09-14 20:18 ` Jason Gunthorpe
2015-09-15 3:08 ` Parav Pandit
2015-09-15 3:45 ` Jason Gunthorpe
2015-09-15 3:45 ` Jason Gunthorpe
2015-09-16 4:41 ` Parav Pandit
2015-09-16 4:41 ` Parav Pandit
2015-09-20 10:35 ` Haggai Eran
2015-09-20 10:35 ` Haggai Eran
2015-10-28 8:14 ` Parav Pandit
2015-10-28 8:14 ` Parav Pandit
2015-09-14 10:15 ` Parav Pandit
2015-09-11 4:43 ` Parav Pandit
2015-09-11 15:03 ` Tejun Heo
2015-09-10 17:48 ` Hefty, Sean
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