Viewing: nrs_delay.c
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2017, Cray Inc. All Rights Reserved.
*
* Copyright (c) 2017, Intel Corporation.
*/
/*
* Network Request Scheduler (NRS) Delay policy
*
* This policy will delay request handling for some configurable amount of
* time.
*
* Author: Chris Horn <hornc@cray.com>
*/
#define DEBUG_SUBSYSTEM S_RPC
#include <linux/random.h>
#include <obd_support.h>
#include <obd_class.h>
#include "ptlrpc_internal.h"
/*
* name delay
*
* The delay policy schedules RPCs so that they are only processed after some
* configurable amount of time (in seconds) has passed.
*
* The defaults were chosen arbitrarily.
*/
#define NRS_POL_NAME_DELAY "delay"
/* Default minimum delay in seconds. */
#define NRS_DELAY_MIN_DEFAULT 5
/* Default maximum delay, in seconds. */
#define NRS_DELAY_MAX_DEFAULT 300
/* Default percentage of delayed RPCs. */
#define NRS_DELAY_PCT_DEFAULT 100
/**
* delay_req_compare() - Binary heap predicate.
* @e1: start time of request
* @e2: start time of second request
*
* Elements are sorted according to the start time assigned to the requests
* upon enqueue. An element with an earlier start time is "less than" an
* element with a later start time.
*
* Return
* * %0 if start_time(e1) > start_time(e2)
* * %1 if start_time(e1) <= start_time(e2)
*/
static int delay_req_compare(struct binheap_node *e1,
struct binheap_node *e2)
{
struct ptlrpc_nrs_request *nrq1;
struct ptlrpc_nrs_request *nrq2;
nrq1 = container_of(e1, struct ptlrpc_nrs_request, nr_node);
nrq2 = container_of(e2, struct ptlrpc_nrs_request, nr_node);
return nrq1->nr_u.delay.req_start_time <=
nrq2->nr_u.delay.req_start_time;
}
static struct binheap_ops nrs_delay_heap_ops = {
.hop_enter = NULL,
.hop_exit = NULL,
.hop_compare = delay_req_compare,
};
/**
* nrs_delay_start() - called to start policy
* @policy: The policy to start
* @arg: Generic char buffer; unused in this policy
* Is called before the policy transitions into
* ptlrpc_nrs_pol_state::NRS_POL_STATE_STARTED; allocates and initializes
* the delay-specific private data structure.
*
* see nrs_policy_register()
* see nrs_policy_ctl()
*
* Return
* * %0 on success
* * %errno on failure (-ENOMEM OOM)
*/
static int nrs_delay_start(struct ptlrpc_nrs_policy *policy, char *arg)
{
struct nrs_delay_data *delay_data;
ENTRY;
OBD_CPT_ALLOC_PTR(delay_data, nrs_pol2cptab(policy),
nrs_pol2cptid(policy));
if (delay_data == NULL)
RETURN(-ENOMEM);
delay_data->delay_binheap = binheap_create(&nrs_delay_heap_ops,
CBH_FLAG_ATOMIC_GROW,
4096, NULL,
nrs_pol2cptab(policy),
nrs_pol2cptid(policy));
if (delay_data->delay_binheap == NULL) {
OBD_FREE_PTR(delay_data);
RETURN(-ENOMEM);
}
delay_data->min_delay = NRS_DELAY_MIN_DEFAULT;
delay_data->max_delay = NRS_DELAY_MAX_DEFAULT;
delay_data->delay_pct = NRS_DELAY_PCT_DEFAULT;
policy->pol_private = delay_data;
RETURN(0);
}
/**
* nrs_delay_stop() - called to stop policy
* @policy: The policy to stop
*
* Is called before the policy transitions into
* ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPED; deallocates the delay-specific
* private data structure.
*
* see __nrs_policy_stop()
*/
static void nrs_delay_stop(struct ptlrpc_nrs_policy *policy)
{
struct nrs_delay_data *delay_data = policy->pol_private;
LASSERT(delay_data != NULL);
LASSERT(delay_data->delay_binheap != NULL);
LASSERT(binheap_is_empty(delay_data->delay_binheap));
binheap_destroy(delay_data->delay_binheap);
OBD_FREE_PTR(delay_data);
}
/**
* nrs_delay_res_get() - Is called for obtaining a delay policy resource.
* @policy: The policy on which the request is being asked for
* @nrq: The request for which resources are being taken
* @parent: Parent resource, unused in this policy
* @resp: Resources references are placed in this array[out]
* @moving_req: Signifies limited caller context; unused in this policy
*
* see nrs_resource_get_safe()
*
* Return 1 The delay policy only has a one-level resource hierarchy
*/
static int nrs_delay_res_get(struct ptlrpc_nrs_policy *policy,
struct ptlrpc_nrs_request *nrq,
const struct ptlrpc_nrs_resource *parent,
struct ptlrpc_nrs_resource **resp, bool moving_req)
{
/**
* Just return the resource embedded inside nrs_delay_data, and end this
* resource hierarchy reference request.
*/
*resp = &((struct nrs_delay_data *)policy->pol_private)->delay_res;
return 1;
}
/**
* nrs_delay_req_get() - Get a request from the delay policy
* @policy: The policy
* @peek: When set, signifies that we just want to examine the request, and not
* handle it, so the request is not removed from the policy.
* @force: Force the policy to return a request
*
* Called when getting a request from the delay policy for handling, or just
* peeking; removes the request from the policy when it is to be handled.
* Requests are only removed from this policy when their start time has
* passed.
*
* see ptlrpc_nrs_req_get_nolock()
* see nrs_request_get()
*
* Return The request to be handled or NULL no request available
*
*/
static
struct ptlrpc_nrs_request *nrs_delay_req_get(struct ptlrpc_nrs_policy *policy,
bool peek, bool force)
{
struct nrs_delay_data *delay_data = policy->pol_private;
struct binheap_node *node;
struct ptlrpc_nrs_request *nrq;
node = binheap_root(delay_data->delay_binheap);
nrq = unlikely(node == NULL) ? NULL :
container_of(node, struct ptlrpc_nrs_request, nr_node);
if (likely(nrq != NULL)) {
if (!force &&
ktime_get_real_seconds() < nrq->nr_u.delay.req_start_time)
nrq = NULL;
else if (likely(!peek))
binheap_remove(delay_data->delay_binheap,
&nrq->nr_node);
}
return nrq;
}
/**
* nrs_delay_req_add() - Adds request @nrq to a delay @policy instance's set of
* queued requests
* @policy: The policy
* @nrq: The request to add
*
* A percentage (delay_pct) of incoming requests are delayed by this policy.
* If selected for delay a request start time is calculated. A start time
* is the current time plus a random offset in the range [min_delay, max_delay]
* The start time is recorded in the request, and is then used by
* delay_req_compare() to maintain a set of requests ordered by their start
* times.
*
* Return
* * %0 request added
* * %1 request not added
*/
static int nrs_delay_req_add(struct ptlrpc_nrs_policy *policy,
struct ptlrpc_nrs_request *nrq)
{
struct nrs_delay_data *delay_data = policy->pol_private;
if (delay_data->delay_pct == 0 || /* Not delaying anything */
(delay_data->delay_pct != 100 &&
delay_data->delay_pct < get_random_u32_below(100)))
return 1;
nrq->nr_u.delay.req_start_time = ktime_get_real_seconds() +
get_random_u32_below(delay_data->max_delay - delay_data->min_delay + 1) +
delay_data->min_delay;
return binheap_insert(delay_data->delay_binheap, &nrq->nr_node);
}
/**
* nrs_delay_req_del() - Removes request @nrq from @policy's list of queued
* requests.
* @policy: The policy
* @nrq: The request to remove
*/
static void nrs_delay_req_del(struct ptlrpc_nrs_policy *policy,
struct ptlrpc_nrs_request *nrq)
{
struct nrs_delay_data *delay_data = policy->pol_private;
binheap_remove(delay_data->delay_binheap, &nrq->nr_node);
}
/**
* nrs_delay_req_stop() - Prints a debug statement right before the
* request @nrq stops being handled.
* @policy: The policy handling the request
* @nrq: The request being handled
*
* see ptlrpc_server_finish_request()
* see ptlrpc_nrs_req_stop_nolock()
*/
static void nrs_delay_req_stop(struct ptlrpc_nrs_policy *policy,
struct ptlrpc_nrs_request *nrq)
{
struct ptlrpc_request *req = container_of(nrq, struct ptlrpc_request,
rq_nrq);
DEBUG_REQ(D_RPCTRACE, req,
"NRS: finished delayed request from %s after %llds",
libcfs_idstr(&req->rq_peer),
(s64)(nrq->nr_u.delay.req_start_time -
req->rq_srv.sr_arrival_time.tv_sec));
}
/**
* nrs_delay_ctl() - Performs ctl functions specific to delay policy instances;
* similar to ioctl
* @policy: the policy instance
* @opc: the opcode
* @arg: used for passing parameters and information[in, out]
*
* pre assert_spin_locked(&policy->pol_nrs->->nrs_lock)
* post assert_spin_locked(&policy->pol_nrs->->nrs_lock)
*
* Return
* * %0 on success (operation carried out successfully)
* * %negative on failure
*/
static int nrs_delay_ctl(struct ptlrpc_nrs_policy *policy,
enum ptlrpc_nrs_ctl opc, void *arg)
{
struct nrs_delay_data *delay_data = policy->pol_private;
__u32 *val = (__u32 *)arg;
assert_spin_locked(&policy->pol_nrs->nrs_lock);
switch (opc) {
default:
RETURN(-EINVAL);
case NRS_CTL_DELAY_RD_MIN:
*val = delay_data->min_delay;
break;
case NRS_CTL_DELAY_WR_MIN:
if (*val > delay_data->max_delay)
RETURN(-EINVAL);
delay_data->min_delay = *val;
break;
case NRS_CTL_DELAY_RD_MAX:
*val = delay_data->max_delay;
break;
case NRS_CTL_DELAY_WR_MAX:
if (*val < delay_data->min_delay)
RETURN(-EINVAL);
delay_data->max_delay = *val;
break;
case NRS_CTL_DELAY_RD_PCT:
*val = delay_data->delay_pct;
break;
case NRS_CTL_DELAY_WR_PCT:
if (*val < 0 || *val > 100)
RETURN(-EINVAL);
delay_data->delay_pct = *val;
break;
}
RETURN(0);
}
/*
* debugfs interface
*/
/* nrs_delay_min and nrs_delay_max are bounded by these values */
#define LPROCFS_NRS_DELAY_LOWER_BOUND 0
#define LPROCFS_NRS_DELAY_UPPER_BOUND 65535
#define LPROCFS_NRS_DELAY_MIN_NAME "delay_min:"
#define LPROCFS_NRS_DELAY_MIN_NAME_REG "reg_delay_min:"
#define LPROCFS_NRS_DELAY_MIN_NAME_HP "hp_delay_min:"
/*
* Max size of the nrs_delay_min seq_write buffer. Needs to be large enough
* to hold the string: "reg_min_delay:65535 hp_min_delay:65535"
*/
#define LPROCFS_NRS_DELAY_MIN_SIZE \
sizeof(LPROCFS_NRS_DELAY_MIN_NAME_REG \
__stringify(LPROCFS_NRS_DELAY_UPPER_BOUND) \
" " LPROCFS_NRS_DELAY_MIN_NAME_HP \
__stringify(LPROCFS_NRS_DELAY_UPPER_BOUND))
#define LPROCFS_NRS_DELAY_MAX_NAME "delay_max:"
#define LPROCFS_NRS_DELAY_MAX_NAME_REG "reg_delay_max:"
#define LPROCFS_NRS_DELAY_MAX_NAME_HP "hp_delay_max:"
/*
* Similar to LPROCFS_NRS_DELAY_MIN_SIZE above, but for the nrs_delay_max
* variable.
*/
#define LPROCFS_NRS_DELAY_MAX_SIZE \
sizeof(LPROCFS_NRS_DELAY_MAX_NAME_REG \
__stringify(LPROCFS_NRS_DELAY_UPPER_BOUND) \
" " LPROCFS_NRS_DELAY_MAX_NAME_HP \
__stringify(LPROCFS_NRS_DELAY_UPPER_BOUND))
#define LPROCFS_NRS_DELAY_PCT_MIN_VAL 0
#define LPROCFS_NRS_DELAY_PCT_MAX_VAL 100
#define LPROCFS_NRS_DELAY_PCT_NAME "delay_pct:"
#define LPROCFS_NRS_DELAY_PCT_NAME_REG "reg_delay_pct:"
#define LPROCFS_NRS_DELAY_PCT_NAME_HP "hp_delay_pct:"
/*
* Similar to LPROCFS_NRS_DELAY_MIN_SIZE above, but for the nrs_delay_pct
* variable.
*/
#define LPROCFS_NRS_DELAY_PCT_SIZE \
sizeof(LPROCFS_NRS_DELAY_PCT_NAME_REG \
__stringify(LPROCFS_NRS_DELAY_PCT_MAX_VAL) \
" " LPROCFS_NRS_DELAY_PCT_NAME_HP \
__stringify(LPROCFS_NRS_DELAY_PCT_MAX_VAL))
/*
* Helper for delay's seq_write functions.
*/
static ssize_t
lprocfs_nrs_delay_seq_write_common(const char __user *buffer,
unsigned int bufsize, size_t count,
const char *var_name, unsigned int min_val,
unsigned int max_val,
struct ptlrpc_service *svc, char *pol_name,
enum ptlrpc_nrs_ctl opc, bool single)
{
enum ptlrpc_nrs_queue_type queue = 0;
char *kernbuf;
char *val_str;
long unsigned int val_reg;
long unsigned int val_hp;
size_t count_copy;
int rc = 0;
char *tmp = NULL;
int tmpsize = 0;
if (count > bufsize - 1)
return -EINVAL;
OBD_ALLOC(kernbuf, bufsize);
if (kernbuf == NULL)
return -ENOMEM;
if (copy_from_user(kernbuf, buffer, count))
GOTO(free_kernbuf, rc = -EFAULT);
tmpsize = strlen("reg_") + strlen(var_name) + 1;
OBD_ALLOC(tmp, tmpsize);
if (tmp == NULL)
GOTO(free_tmp, rc = -ENOMEM);
/* look for "reg_<var_name>" in kernbuf */
snprintf(tmp, tmpsize, "reg_%s", var_name);
count_copy = count;
val_str = lprocfs_find_named_value(kernbuf, tmp, &count_copy);
if (val_str != kernbuf) {
rc = kstrtoul(val_str, 10, &val_reg);
if (rc != 0)
GOTO(free_tmp, rc = -EINVAL);
queue |= PTLRPC_NRS_QUEUE_REG;
}
/* look for "hp_<var_name>" in kernbuf */
snprintf(tmp, tmpsize, "hp_%s", var_name);
count_copy = count;
val_str = lprocfs_find_named_value(kernbuf, tmp, &count_copy);
if (val_str != kernbuf) {
if (!nrs_svc_has_hp(svc))
GOTO(free_tmp, rc = -ENODEV);
rc = kstrtoul(val_str, 10, &val_hp);
if (rc != 0)
GOTO(free_tmp, rc = -EINVAL);
queue |= PTLRPC_NRS_QUEUE_HP;
}
if (queue == 0) {
if (!isdigit(kernbuf[0]))
GOTO(free_tmp, rc = -EINVAL);
rc = kstrtoul(kernbuf, 10, &val_reg);
if (rc != 0)
GOTO(free_tmp, rc = -EINVAL);
queue = PTLRPC_NRS_QUEUE_REG;
if (nrs_svc_has_hp(svc)) {
queue |= PTLRPC_NRS_QUEUE_HP;
val_hp = val_reg;
}
}
if (queue & PTLRPC_NRS_QUEUE_REG) {
if (val_reg > max_val || val_reg < min_val)
GOTO(free_tmp, rc = -EINVAL);
rc = ptlrpc_nrs_policy_control(svc, PTLRPC_NRS_QUEUE_REG,
pol_name, opc, single, &val_reg);
if ((rc < 0 && rc != -ENODEV) ||
(rc == -ENODEV && queue == PTLRPC_NRS_QUEUE_REG))
GOTO(free_tmp, rc);
}
if (queue & PTLRPC_NRS_QUEUE_HP) {
int rc2 = 0;
if (val_hp > max_val || val_hp < min_val)
GOTO(free_tmp, rc = -EINVAL);
rc2 = ptlrpc_nrs_policy_control(svc, PTLRPC_NRS_QUEUE_HP,
pol_name, opc, single, &val_hp);
if ((rc2 < 0 && rc2 != -ENODEV) ||
(rc2 == -ENODEV && queue == PTLRPC_NRS_QUEUE_HP))
GOTO(free_tmp, rc = rc2);
}
/* If we've reached here then we want to return count */
rc = count;
free_tmp:
OBD_FREE(tmp, tmpsize);
free_kernbuf:
OBD_FREE(kernbuf, bufsize);
return rc;
}
/*
* Retrieves the value of the minimum delay for delay policy instances on both
* the regular and high-priority NRS head of a service, as long as a policy
* instance is not in the ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPED state;
*/
static int
ptlrpc_lprocfs_nrs_delay_min_seq_show(struct seq_file *m, void *data)
{
struct ptlrpc_service *svc = m->private;
unsigned int min_delay;
int rc;
rc = ptlrpc_nrs_policy_control(svc, PTLRPC_NRS_QUEUE_REG,
NRS_POL_NAME_DELAY,
NRS_CTL_DELAY_RD_MIN,
true, &min_delay);
if (rc == 0)
seq_printf(m, LPROCFS_NRS_DELAY_MIN_NAME_REG"%-5d\n",
min_delay);
/**
* Ignore -ENODEV as the regular NRS head's policy may be in
* the ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPED state.
*/
else if (rc != -ENODEV)
return rc;
if (!nrs_svc_has_hp(svc))
return 0;
rc = ptlrpc_nrs_policy_control(svc, PTLRPC_NRS_QUEUE_HP,
NRS_POL_NAME_DELAY,
NRS_CTL_DELAY_RD_MIN,
true, &min_delay);
if (rc == 0)
seq_printf(m, LPROCFS_NRS_DELAY_MIN_NAME_HP"%-5d\n",
min_delay);
/**
* Ignore -ENODEV as the regular NRS head's policy may be in
* the ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPED state.
*/
else if (rc == -ENODEV)
rc = 0;
return rc;
}
/*
* Sets the value of the minimum request delay for delay policy instances of a
* service. The user can set the minimum request delay for the regular or high
* priority NRS head individually by specifying each value, or both together in
* a single invocation.
*
* For example:
*
* lctl set_param *.*.*.nrs_delay_min=reg_delay_min:5, to set the regular
* request minimum delay on all PtlRPC services to 5 seconds
*
* lctl set_param *.*.*.nrs_delay_min=hp_delay_min:2, to set the high-priority
* request minimum delay on all PtlRPC services to 2 seconds, and
*
* lctl set_param *.*.ost_io.nrs_delay_min=8, to set both the regular and
* high priority request minimum delay of the ost_io service to 8 seconds.
*/
static ssize_t
ptlrpc_lprocfs_nrs_delay_min_seq_write(struct file *file,
const char __user *buffer, size_t count,
loff_t *off)
{
struct seq_file *m = file->private_data;
struct ptlrpc_service *svc = m->private;
return lprocfs_nrs_delay_seq_write_common(buffer,
LPROCFS_NRS_DELAY_MIN_SIZE,
count,
LPROCFS_NRS_DELAY_MIN_NAME,
LPROCFS_NRS_DELAY_LOWER_BOUND,
LPROCFS_NRS_DELAY_UPPER_BOUND,
svc, NRS_POL_NAME_DELAY,
NRS_CTL_DELAY_WR_MIN, false);
}
LDEBUGFS_SEQ_FOPS(ptlrpc_lprocfs_nrs_delay_min);
/*
* Retrieves the value of the maximum delay for delay policy instances on both
* the regular and high-priority NRS head of a service, as long as a policy
* instance is not in the ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPED state;
*/
static int
ptlrpc_lprocfs_nrs_delay_max_seq_show(struct seq_file *m, void *data)
{
struct ptlrpc_service *svc = m->private;
unsigned int max_delay;
int rc;
rc = ptlrpc_nrs_policy_control(svc, PTLRPC_NRS_QUEUE_REG,
NRS_POL_NAME_DELAY,
NRS_CTL_DELAY_RD_MAX,
true, &max_delay);
if (rc == 0)
seq_printf(m, LPROCFS_NRS_DELAY_MAX_NAME_REG"%-5d\n",
max_delay);
/**
* Ignore -ENODEV as the regular NRS head's policy may be in
* the ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPED state.
*/
else if (rc != -ENODEV)
return rc;
if (!nrs_svc_has_hp(svc))
return 0;
rc = ptlrpc_nrs_policy_control(svc, PTLRPC_NRS_QUEUE_HP,
NRS_POL_NAME_DELAY,
NRS_CTL_DELAY_RD_MAX,
true, &max_delay);
if (rc == 0)
seq_printf(m, LPROCFS_NRS_DELAY_MAX_NAME_HP"%-5d\n",
max_delay);
/**
* Ignore -ENODEV as the regular NRS head's policy may be in
* the ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPED state.
*/
else if (rc == -ENODEV)
rc = 0;
return rc;
}
/*
* Sets the value of the maximum request delay for delay policy instances of a
* service. The user can set the maximum request delay for the regular or high
* priority NRS head individually by specifying each value, or both together in
* a single invocation.
*
* For example:
*
* lctl set_param *.*.*.nrs_delay_max=reg_delay_max:20, to set the regular
* request maximum delay on all PtlRPC services to 20 seconds
*
* lctl set_param *.*.*.nrs_delay_max=hp_delay_max:10, to set the high-priority
* request maximum delay on all PtlRPC services to 10 seconds, and
*
* lctl set_param *.*.ost_io.nrs_delay_max=35, to set both the regular and
* high priority request maximum delay of the ost_io service to 35 seconds.
*/
static ssize_t
ptlrpc_lprocfs_nrs_delay_max_seq_write(struct file *file,
const char __user *buffer, size_t count,
loff_t *off)
{
struct seq_file *m = file->private_data;
struct ptlrpc_service *svc = m->private;
return lprocfs_nrs_delay_seq_write_common(buffer,
LPROCFS_NRS_DELAY_MAX_SIZE,
count,
LPROCFS_NRS_DELAY_MAX_NAME,
LPROCFS_NRS_DELAY_LOWER_BOUND,
LPROCFS_NRS_DELAY_UPPER_BOUND,
svc, NRS_POL_NAME_DELAY,
NRS_CTL_DELAY_WR_MAX, false);
}
LDEBUGFS_SEQ_FOPS(ptlrpc_lprocfs_nrs_delay_max);
/*
* Retrieves the value of the percentage of requests which should be delayed
* for delay policy instances on both the regular and high-priority NRS head
* of a service, as long as a policy instance is not in the
* ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPED state;
*/
static int
ptlrpc_lprocfs_nrs_delay_pct_seq_show(struct seq_file *m, void *data)
{
struct ptlrpc_service *svc = m->private;
unsigned int delay_pct;
int rc;
rc = ptlrpc_nrs_policy_control(svc, PTLRPC_NRS_QUEUE_REG,
NRS_POL_NAME_DELAY,
NRS_CTL_DELAY_RD_PCT,
true, &delay_pct);
if (rc == 0)
seq_printf(m, LPROCFS_NRS_DELAY_PCT_NAME_REG"%-3d\n",
delay_pct);
/**
* Ignore -ENODEV as the regular NRS head's policy may be in
* the ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPED state.
*/
else if (rc != -ENODEV)
return rc;
if (!nrs_svc_has_hp(svc))
return 0;
rc = ptlrpc_nrs_policy_control(svc, PTLRPC_NRS_QUEUE_HP,
NRS_POL_NAME_DELAY,
NRS_CTL_DELAY_RD_PCT,
true, &delay_pct);
if (rc == 0)
seq_printf(m, LPROCFS_NRS_DELAY_PCT_NAME_HP"%-3d\n",
delay_pct);
/**
* Ignore -ENODEV as the regular NRS head's policy may be in
* the ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPED state.
*/
else if (rc == -ENODEV)
rc = 0;
return rc;
}
/*
* Sets the value of the percentage of requests to be delayed for delay policy
* instances of a service. The user can set the percentage for the regular or
* high-priority NRS head individually by specifying each value, or both
* together in a single invocation.
*
* For example:
*
* lctl set_param *.*.*.nrs_delay_pct=reg_delay_pct:5, to delay 5 percent of
* regular requests on all PtlRPC services
*
* lctl set_param *.*.*.nrs_delay_pct=hp_delay_pct:2, to delay 2 percent of
* high-priority requests on all PtlRPC services, and
*
* lctl set_param *.*.ost_io.nrs_delay_pct=8, to delay 8 percent of both
* regular and high-priority requests of the ost_io service.
*/
static ssize_t
ptlrpc_lprocfs_nrs_delay_pct_seq_write(struct file *file,
const char __user *buffer, size_t count,
loff_t *off)
{
struct seq_file *m = file->private_data;
struct ptlrpc_service *svc = m->private;
return lprocfs_nrs_delay_seq_write_common(buffer,
LPROCFS_NRS_DELAY_PCT_SIZE,
count,
LPROCFS_NRS_DELAY_PCT_NAME,
LPROCFS_NRS_DELAY_PCT_MIN_VAL,
LPROCFS_NRS_DELAY_PCT_MAX_VAL,
svc, NRS_POL_NAME_DELAY,
NRS_CTL_DELAY_WR_PCT, false);
}
LDEBUGFS_SEQ_FOPS(ptlrpc_lprocfs_nrs_delay_pct);
static int nrs_delay_lprocfs_init(struct ptlrpc_service *svc)
{
struct ldebugfs_vars nrs_delay_lprocfs_vars[] = {
{ .name = "nrs_delay_min",
.fops = &ptlrpc_lprocfs_nrs_delay_min_fops,
.data = svc },
{ .name = "nrs_delay_max",
.fops = &ptlrpc_lprocfs_nrs_delay_max_fops,
.data = svc },
{ .name = "nrs_delay_pct",
.fops = &ptlrpc_lprocfs_nrs_delay_pct_fops,
.data = svc },
{ NULL }
};
if (!svc->srv_debugfs_entry)
return 0;
ldebugfs_add_vars(svc->srv_debugfs_entry, nrs_delay_lprocfs_vars, NULL);
return 0;
}
/*
* Delay policy operations
*/
static const struct ptlrpc_nrs_pol_ops nrs_delay_ops = {
.op_policy_start = nrs_delay_start,
.op_policy_stop = nrs_delay_stop,
.op_policy_ctl = nrs_delay_ctl,
.op_res_get = nrs_delay_res_get,
.op_req_get = nrs_delay_req_get,
.op_req_enqueue = nrs_delay_req_add,
.op_req_dequeue = nrs_delay_req_del,
.op_req_stop = nrs_delay_req_stop,
.op_lprocfs_init = nrs_delay_lprocfs_init,
};
/*
* Delay policy configuration
*/
struct ptlrpc_nrs_pol_conf nrs_conf_delay = {
.nc_name = NRS_POL_NAME_DELAY,
.nc_ops = &nrs_delay_ops,
.nc_compat = nrs_policy_compat_all,
};
