Viewing: ptlrpcd.c
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
* Use is subject to license terms.
*
* Copyright (c) 2011, 2017, Intel Corporation.
*/
/*
* This file is part of Lustre, http://www.lustre.org/
*
* ptlrpcd is a special thread with its own set where other user might add
* requests when they don't want to wait for their completion.
* PtlRPCD will take care of sending such requests and then processing their
* replies and calling completion callbacks as necessary.
* The callbacks are called directly from ptlrpcd context.
* It is important to never significantly block (esp. on RPCs!) within such
* completion handler or a deadlock might occur where ptlrpcd enters some
* callback that attempts to send another RPC and wait for it to return,
* during which time ptlrpcd is completely blocked, so e.g. if import
* fails, recovery cannot progress because connection requests are also
* sent by ptlrpcd.
*/
#define DEBUG_SUBSYSTEM S_RPC
#include <linux/fs_struct.h>
#include <linux/kthread.h>
#include <lustre_net.h>
#include <lustre_lib.h>
#include <lustre_ha.h>
#include <obd_class.h> /* for obd_zombie */
#include <obd_support.h>
#include <cl_object.h> /* cl_env_{get,put}() */
#include <lprocfs_status.h>
#include "ptlrpc_internal.h"
/* One of these per CPT. */
struct ptlrpcd {
int pd_size;
int pd_index;
int pd_cpt;
int pd_cursor;
int pd_nthreads;
int pd_groupsize;
struct ptlrpcd_ctl pd_threads[];
};
/*
* max_ptlrpcds is obsolete, but retained to ensure that the kernel
* module will load on a system where it has been tuned.
* A value other than 0 implies it was tuned, in which case the value
* is used to derive a setting for ptlrpcd_per_cpt_max.
*/
static int max_ptlrpcds;
module_param(max_ptlrpcds, int, 0644);
MODULE_PARM_DESC(max_ptlrpcds,
"Max ptlrpcd thread count to be started (obsolete).");
/*
* ptlrpcd_bind_policy is obsolete, but retained to ensure that
* the kernel module will load on a system where it has been tuned.
* A value other than 0 implies it was tuned, in which case the value
* is used to derive a setting for ptlrpcd_partner_group_size.
*/
static int ptlrpcd_bind_policy;
module_param(ptlrpcd_bind_policy, int, 0644);
MODULE_PARM_DESC(ptlrpcd_bind_policy,
"Ptlrpcd threads binding mode (obsolete).");
/*
* ptlrpcd_per_cpt_max: The maximum number of ptlrpcd threads to run
* in a CPT.
*/
static int ptlrpcd_per_cpt_max;
module_param(ptlrpcd_per_cpt_max, int, 0644);
MODULE_PARM_DESC(ptlrpcd_per_cpt_max,
"Max ptlrpcd thread count to be started per CPT.");
/*
* ptlrpcd_partner_group_size: The desired number of threads in each
* ptlrpcd partner thread group. Default is 2, corresponding to the
* old PDB_POLICY_PAIR. A negative value makes all ptlrpcd threads in
* a CPT partners of each other.
*/
static int ptlrpcd_partner_group_size;
module_param(ptlrpcd_partner_group_size, int, 0644);
MODULE_PARM_DESC(ptlrpcd_partner_group_size,
"Number of ptlrpcd threads in a partner group.");
/*
* ptlrpcd_cpts: A CPT string describing the CPU partitions that
* ptlrpcd threads should run on. Used to make ptlrpcd threads run on
* a subset of all CPTs.
*
* ptlrpcd_cpts=2
* ptlrpcd_cpts=[2]
* run ptlrpcd threads only on CPT 2.
*
* ptlrpcd_cpts=0-3
* ptlrpcd_cpts=[0-3]
* run ptlrpcd threads on CPTs 0, 1, 2, and 3.
*
* ptlrpcd_cpts=[0-3,5,7]
* run ptlrpcd threads on CPTS 0, 1, 2, 3, 5, and 7.
*/
static char *ptlrpcd_cpts;
module_param(ptlrpcd_cpts, charp, 0644);
MODULE_PARM_DESC(ptlrpcd_cpts,
"CPU partitions ptlrpcd threads should run in");
/* ptlrpcds_cpt_idx maps cpt numbers to an index in the ptlrpcds array. */
static int *ptlrpcds_cpt_idx;
/* ptlrpcds_num is the number of entries in the ptlrpcds array. */
static int ptlrpcds_num;
static struct ptlrpcd **ptlrpcds;
/*
* In addition to the regular thread pool above, there is a single
* global recovery thread. Recovery isn't critical for performance,
* and doesn't block, but must always be able to proceed, and it is
* possible that all normal ptlrpcd threads are blocked. Hence the
* need for a dedicated thread.
*/
static struct ptlrpcd_ctl ptlrpcd_rcv;
struct mutex ptlrpcd_mutex;
static int ptlrpcd_users = 0;
void ptlrpcd_wake(struct ptlrpc_request *req)
{
struct ptlrpc_request_set *set = req->rq_set;
LASSERT(set != NULL);
wake_up(&set->set_waitq);
}
EXPORT_SYMBOL(ptlrpcd_wake);
static struct ptlrpcd_ctl *
ptlrpcd_select_pc(struct ptlrpc_request *req)
{
struct ptlrpcd *pd;
int cpt;
int idx;
if (req != NULL && req->rq_send_state != LUSTRE_IMP_FULL)
return &ptlrpcd_rcv;
cpt = cfs_cpt_current(cfs_cpt_tab, 1);
if (ptlrpcds_cpt_idx == NULL)
idx = cpt;
else
idx = ptlrpcds_cpt_idx[cpt];
pd = ptlrpcds[idx];
/* We do not care whether it is strict load balance. */
idx = pd->pd_cursor;
if (++idx == pd->pd_nthreads)
idx = 0;
pd->pd_cursor = idx;
return &pd->pd_threads[idx];
}
/*
* Return transferred RPCs count.
*/
static int ptlrpcd_steal_rqset(struct ptlrpc_request_set *des,
struct ptlrpc_request_set *src)
{
struct ptlrpc_request *req;
int rc = 0;
spin_lock(&src->set_new_req_lock);
if (likely(!list_empty(&src->set_new_requests))) {
list_for_each_entry(req, &src->set_new_requests, rq_set_chain)
req->rq_set = des;
list_splice_init(&src->set_new_requests,
&des->set_requests);
rc = atomic_read(&src->set_new_count);
atomic_add(rc, &des->set_remaining);
atomic_set(&src->set_new_count, 0);
}
spin_unlock(&src->set_new_req_lock);
return rc;
}
/**
* ptlrpcd_add_req() - Requests that are added to the ptlrpcd queue
* @req: request to add to ptlrpcd
*
* Requests that are added to the ptlrpcd queue are sent via
* ptlrpcd_check->ptlrpc_check_set().
*/
void ptlrpcd_add_req(struct ptlrpc_request *req)
{
struct ptlrpcd_ctl *pc;
if (req->rq_reqmsg)
lustre_msg_set_jobinfo(req->rq_reqmsg, NULL);
spin_lock(&req->rq_lock);
if (req->rq_invalid_rqset) {
req->rq_invalid_rqset = 0;
spin_unlock(&req->rq_lock);
if (wait_event_idle_timeout(req->rq_set_waitq,
req->rq_set == NULL,
cfs_time_seconds(5)) == 0)
l_wait_event_abortable(req->rq_set_waitq,
req->rq_set == NULL);
} else if (req->rq_set) {
/*
* If we have a vaid "rq_set", just reuse it to avoid double
* linked.
*/
LASSERT(req->rq_phase == RQ_PHASE_NEW);
LASSERT(req->rq_send_state == LUSTRE_IMP_REPLAY);
/* ptlrpc_check_set will decrease the count */
atomic_inc(&req->rq_set->set_remaining);
spin_unlock(&req->rq_lock);
wake_up(&req->rq_set->set_waitq);
return;
} else {
spin_unlock(&req->rq_lock);
}
pc = ptlrpcd_select_pc(req);
DEBUG_REQ(D_INFO, req, "add req [%p] to pc [%s+%d]",
req, pc->pc_name, pc->pc_index);
ptlrpc_set_add_new_req(pc, req);
}
EXPORT_SYMBOL(ptlrpcd_add_req);
/*
* Check if there is more work to do on ptlrpcd set.
* Returns 1 if yes.
*/
static int ptlrpcd_check(struct lu_env *env, struct ptlrpcd_ctl *pc)
{
struct ptlrpc_request *req, *tmp;
struct ptlrpc_request_set *set = pc->pc_set;
int rc = 0;
int rc2;
ENTRY;
if (atomic_read(&set->set_new_count)) {
spin_lock(&set->set_new_req_lock);
if (likely(!list_empty(&set->set_new_requests))) {
list_splice_init(&set->set_new_requests,
&set->set_requests);
atomic_add(atomic_read(&set->set_new_count),
&set->set_remaining);
atomic_set(&set->set_new_count, 0);
/*
* Need to calculate its timeout.
*/
rc = 1;
}
spin_unlock(&set->set_new_req_lock);
}
/*
* We should call lu_env_refill() before handling new requests to make
* sure that env key the requests depending on really exists.
*/
rc2 = lu_env_refill(env);
if (rc2 != 0) {
/*
* XXX This is very awkward situation, because
* execution can neither continue (request
* interpreters assume that env is set up), nor repeat
* the loop (as this potentially results in a tight
* loop of -ENOMEM's).
*
* Fortunately, refill only ever does something when
* new modules are loaded, i.e., early during boot up.
*/
CERROR("Failure to refill session: %d\n", rc2);
RETURN(rc);
}
if (atomic_read(&set->set_remaining))
rc |= ptlrpc_check_set(env, set);
/*
* NB: ptlrpc_check_set has already moved complted request at the
* head of seq::set_requests
*/
list_for_each_entry_safe(req, tmp, &set->set_requests, rq_set_chain) {
if (req->rq_phase != RQ_PHASE_COMPLETE)
break;
list_del_init(&req->rq_set_chain);
req->rq_set = NULL;
ptlrpc_req_put(req);
}
if (rc == 0) {
/*
* If new requests have been added, make sure to wake up.
*/
rc = atomic_read(&set->set_new_count);
/*
* If we have nothing to do, check whether we can take some
* work from our partner threads.
*/
if (rc == 0 && pc->pc_npartners > 0) {
struct ptlrpcd_ctl *partner;
struct ptlrpc_request_set *ps;
int first = pc->pc_cursor;
do {
partner = pc->pc_partners[pc->pc_cursor++];
if (pc->pc_cursor >= pc->pc_npartners)
pc->pc_cursor = 0;
if (partner == NULL)
continue;
spin_lock(&partner->pc_lock);
ps = partner->pc_set;
if (ps == NULL) {
spin_unlock(&partner->pc_lock);
continue;
}
kref_get(&ps->set_refcount);
spin_unlock(&partner->pc_lock);
if (atomic_read(&ps->set_new_count)) {
rc = ptlrpcd_steal_rqset(set, ps);
if (rc > 0)
CDEBUG(D_RPCTRACE,
"transfer %d async RPCs [%d->%d]\n",
rc, partner->pc_index,
pc->pc_index);
}
kref_put(&ps->set_refcount, ptlrpc_reqset_free);
} while (rc == 0 && pc->pc_cursor != first);
}
}
RETURN(rc || test_bit(LIOD_STOP, &pc->pc_flags));
}
/**
* ptlrpcd() - Main ptlrpcd thread.
* @arg: pointer to struct ptlrpcd_ctl
*
* ptlrpc's code paths like to execute in process context, so we have this
* thread which spins on a set which contains the rpcs and sends them.
*
* Return:
* * %0 on success
* * %negative on failure
*/
static int ptlrpcd(void *arg)
{
struct ptlrpcd_ctl *pc = arg;
struct ptlrpc_request_set *set;
struct lu_context ses = { 0 };
struct lu_env env = { .le_ses = &ses };
int rc = 0;
int exit = 0;
ENTRY;
unshare_fs_struct();
if (cfs_cpt_bind(cfs_cpt_tab, pc->pc_cpt) != 0)
CWARN("Failed to bind %s on CPT %d\n", pc->pc_name, pc->pc_cpt);
/*
* Allocate the request set after the thread has been bound
* above. This is safe because no requests will be queued
* until all ptlrpcd threads have confirmed that they have
* successfully started.
*/
set = ptlrpc_prep_set();
if (set == NULL)
GOTO(failed, rc = -ENOMEM);
spin_lock(&pc->pc_lock);
pc->pc_set = set;
spin_unlock(&pc->pc_lock);
/* Both client and server (MDT/OST) may use the environment. */
rc = lu_context_init(&env.le_ctx, LCT_MD_THREAD |
LCT_DT_THREAD |
LCT_CL_THREAD |
LCT_REMEMBER |
LCT_NOREF);
if (rc != 0)
GOTO(failed, rc);
rc = lu_context_init(env.le_ses, LCT_SESSION |
LCT_REMEMBER |
LCT_NOREF);
if (rc != 0) {
lu_context_fini(&env.le_ctx);
GOTO(failed, rc);
}
complete(&pc->pc_starting);
/*
* This mainloop strongly resembles ptlrpc_set_wait() except that our
* set never completes. ptlrpcd_check() calls ptlrpc_check_set() when
* there are requests in the set. New requests come in on the set's
* new_req_list and ptlrpcd_check() moves them into the set.
*/
do {
DEFINE_WAIT_FUNC(wait, woken_wake_function);
time64_t timeout;
timeout = cfs_time_seconds(ptlrpc_set_next_timeout(set));
lu_context_enter(&env.le_ctx);
lu_context_enter(env.le_ses);
add_wait_queue(&set->set_waitq, &wait);
while (!ptlrpcd_check(&env, pc)) {
int ret;
if (timeout == 0)
ret = wait_woken(&wait, TASK_IDLE,
MAX_SCHEDULE_TIMEOUT);
else {
ret = wait_woken(&wait, TASK_IDLE, timeout);
if (ret > 0)
timeout = ret;
}
if (ret != 0)
continue;
/* Timed out */
ptlrpc_expired_set(set);
break;
}
remove_wait_queue(&set->set_waitq, &wait);
lu_context_exit(&env.le_ctx);
lu_context_exit(env.le_ses);
/*
* Abort inflight rpcs for forced stop case.
*/
if (test_bit(LIOD_STOP, &pc->pc_flags)) {
if (test_bit(LIOD_FORCE, &pc->pc_flags))
ptlrpc_abort_set(set);
exit++;
}
/*
* Let's make one more loop to make sure that ptlrpcd_check()
* copied all raced new rpcs into the set so we can kill them.
*/
} while (exit < 2);
/*
* Wait for inflight requests to drain.
*/
if (!list_empty(&set->set_requests))
ptlrpc_set_wait(&env, set);
lu_context_fini(&env.le_ctx);
lu_context_fini(env.le_ses);
complete(&pc->pc_finishing);
return 0;
failed:
pc->pc_error = rc;
complete(&pc->pc_starting);
RETURN(rc);
}
static void ptlrpcd_ctl_init(struct ptlrpcd_ctl *pc, int index, int cpt)
{
ENTRY;
pc->pc_index = index;
pc->pc_cpt = cpt;
init_completion(&pc->pc_starting);
init_completion(&pc->pc_finishing);
spin_lock_init(&pc->pc_lock);
if (index < 0) {
/* Recovery thread. */
snprintf(pc->pc_name, sizeof(pc->pc_name), "ptlrpcd_rcv");
} else {
/* Regular thread. */
snprintf(pc->pc_name, sizeof(pc->pc_name),
"ptlrpcd_%02d_%02d", cpt, index);
}
EXIT;
}
/* XXX: We want multiple CPU cores to share the async RPC load. So we
* start many ptlrpcd threads. We also want to reduce the ptlrpcd
* overhead caused by data transfer cross-CPU cores. So we bind
* all ptlrpcd threads to a CPT, in the expectation that CPTs
* will be defined in a way that matches these boundaries. Within
* a CPT a ptlrpcd thread can be scheduled on any available core.
*
* Each ptlrpcd thread has its own request queue. This can cause
* response delay if the thread is already busy. To help with
* this we define partner threads: these are other threads bound
* to the same CPT which will check for work in each other's
* request queues if they have no work to do.
*
* The desired number of partner threads can be tuned by setting
* ptlrpcd_partner_group_size. The default is to create pairs of
* partner threads.
*/
static int ptlrpcd_partners(struct ptlrpcd *pd, int index)
{
struct ptlrpcd_ctl *pc;
struct ptlrpcd_ctl **ppc;
int first;
int i;
int rc = 0;
ENTRY;
LASSERT(index >= 0 && index < pd->pd_nthreads);
pc = &pd->pd_threads[index];
pc->pc_npartners = pd->pd_groupsize - 1;
if (pc->pc_npartners <= 0)
GOTO(out, rc);
OBD_CPT_ALLOC(pc->pc_partners, cfs_cpt_tab, pc->pc_cpt,
sizeof(struct ptlrpcd_ctl *) * pc->pc_npartners);
if (pc->pc_partners == NULL) {
pc->pc_npartners = 0;
GOTO(out, rc = -ENOMEM);
}
first = index - index % pd->pd_groupsize;
ppc = pc->pc_partners;
for (i = first; i < first + pd->pd_groupsize; i++) {
if (i != index)
*ppc++ = &pd->pd_threads[i];
}
out:
RETURN(rc);
}
int ptlrpcd_start(struct ptlrpcd_ctl *pc)
{
struct task_struct *task;
int rc = 0;
ENTRY;
/*
* Do not allow starting a second thread for one pc.
*/
if (test_and_set_bit(LIOD_START, &pc->pc_flags)) {
CWARN("Starting second thread (%s) for same pc %p\n",
pc->pc_name, pc);
RETURN(0);
}
task = kthread_run(ptlrpcd, pc, "%s", pc->pc_name);
if (IS_ERR(task))
GOTO(out_set, rc = PTR_ERR(task));
wait_for_completion(&pc->pc_starting);
rc = pc->pc_error;
if (rc != 0)
GOTO(out_set, rc);
RETURN(0);
out_set:
if (pc->pc_set != NULL) {
struct ptlrpc_request_set *set = pc->pc_set;
spin_lock(&pc->pc_lock);
pc->pc_set = NULL;
spin_unlock(&pc->pc_lock);
ptlrpc_set_destroy(set);
}
clear_bit(LIOD_START, &pc->pc_flags);
RETURN(rc);
}
void ptlrpcd_stop(struct ptlrpcd_ctl *pc, int force)
{
ENTRY;
if (!test_bit(LIOD_START, &pc->pc_flags)) {
CWARN("Thread for pc %p was not started\n", pc);
goto out;
}
set_bit(LIOD_STOP, &pc->pc_flags);
if (force)
set_bit(LIOD_FORCE, &pc->pc_flags);
wake_up(&pc->pc_set->set_waitq);
out:
EXIT;
}
void ptlrpcd_free(struct ptlrpcd_ctl *pc)
{
struct ptlrpc_request_set *set = pc->pc_set;
ENTRY;
if (!test_bit(LIOD_START, &pc->pc_flags)) {
CWARN("Thread for pc %p was not started\n", pc);
goto out;
}
wait_for_completion(&pc->pc_finishing);
spin_lock(&pc->pc_lock);
pc->pc_set = NULL;
spin_unlock(&pc->pc_lock);
ptlrpc_set_destroy(set);
clear_bit(LIOD_START, &pc->pc_flags);
clear_bit(LIOD_STOP, &pc->pc_flags);
clear_bit(LIOD_FORCE, &pc->pc_flags);
out:
if (pc->pc_npartners > 0) {
LASSERT(pc->pc_partners != NULL);
OBD_FREE_PTR_ARRAY(pc->pc_partners, pc->pc_npartners);
pc->pc_partners = NULL;
}
pc->pc_npartners = 0;
pc->pc_error = 0;
EXIT;
}
static void ptlrpcd_fini(void)
{
int i;
int j;
int ncpts;
ENTRY;
if (ptlrpcds != NULL) {
for (i = 0; i < ptlrpcds_num; i++) {
if (ptlrpcds[i] == NULL)
break;
for (j = 0; j < ptlrpcds[i]->pd_nthreads; j++)
ptlrpcd_stop(&ptlrpcds[i]->pd_threads[j], 0);
for (j = 0; j < ptlrpcds[i]->pd_nthreads; j++)
ptlrpcd_free(&ptlrpcds[i]->pd_threads[j]);
OBD_FREE(ptlrpcds[i], ptlrpcds[i]->pd_size);
ptlrpcds[i] = NULL;
}
OBD_FREE_PTR_ARRAY(ptlrpcds, ptlrpcds_num);
}
ptlrpcds_num = 0;
ptlrpcd_stop(&ptlrpcd_rcv, 0);
ptlrpcd_free(&ptlrpcd_rcv);
if (ptlrpcds_cpt_idx != NULL) {
ncpts = cfs_cpt_number(cfs_cpt_tab);
OBD_FREE_PTR_ARRAY(ptlrpcds_cpt_idx, ncpts);
ptlrpcds_cpt_idx = NULL;
}
EXIT;
}
static int ptlrpcd_init(void)
{
int nthreads;
int groupsize;
int size;
int i;
int j;
int rc = 0;
struct cfs_cpt_table *cptable;
__u32 *cpts = NULL;
int ncpts;
int cpt;
struct ptlrpcd *pd;
ENTRY;
/*
* Determine the CPTs that ptlrpcd threads will run on.
*/
cptable = cfs_cpt_tab;
ncpts = cfs_cpt_number(cptable);
if (ptlrpcd_cpts != NULL) {
struct cfs_expr_list *el;
size = ncpts * sizeof(ptlrpcds_cpt_idx[0]);
OBD_ALLOC(ptlrpcds_cpt_idx, size);
if (ptlrpcds_cpt_idx == NULL)
GOTO(out, rc = -ENOMEM);
rc = cfs_expr_list_parse(ptlrpcd_cpts,
strlen(ptlrpcd_cpts),
0, ncpts - 1, &el);
if (rc != 0) {
CERROR("%s: invalid CPT pattern string: %s",
"ptlrpcd_cpts", ptlrpcd_cpts);
GOTO(out, rc = -EINVAL);
}
rc = cfs_expr_list_values(el, ncpts, &cpts);
cfs_expr_list_free(el);
if (rc <= 0) {
CERROR("%s: failed to parse CPT array %s: %d\n",
"ptlrpcd_cpts", ptlrpcd_cpts, rc);
if (rc == 0)
rc = -EINVAL;
GOTO(out, rc);
}
/*
* Create the cpt-to-index map. When there is no match
* in the cpt table, pick a cpt at random. This could
* be changed to take the topology of the system into
* account.
*/
for (cpt = 0; cpt < ncpts; cpt++) {
for (i = 0; i < rc; i++)
if (cpts[i] == cpt)
break;
if (i >= rc)
i = cpt % rc;
ptlrpcds_cpt_idx[cpt] = i;
}
ncpts = rc;
}
ptlrpcds_num = ncpts;
size = ncpts * sizeof(ptlrpcds[0]);
OBD_ALLOC(ptlrpcds, size);
if (ptlrpcds == NULL)
GOTO(out, rc = -ENOMEM);
/*
* The max_ptlrpcds parameter is obsolete, but do something
* sane if it has been tuned, and complain if
* ptlrpcd_per_cpt_max has also been tuned.
*/
if (max_ptlrpcds != 0) {
CWARN("max_ptlrpcds is obsolete.\n");
if (ptlrpcd_per_cpt_max == 0) {
ptlrpcd_per_cpt_max = max_ptlrpcds / ncpts;
/* Round up if there is a remainder. */
if (max_ptlrpcds % ncpts != 0)
ptlrpcd_per_cpt_max++;
CWARN("Setting ptlrpcd_per_cpt_max = %d\n",
ptlrpcd_per_cpt_max);
} else {
CWARN("ptlrpd_per_cpt_max is also set!\n");
}
}
/*
* The ptlrpcd_bind_policy parameter is obsolete, but do
* something sane if it has been tuned, and complain if
* ptlrpcd_partner_group_size is also tuned.
*/
if (ptlrpcd_bind_policy != 0) {
CWARN("ptlrpcd_bind_policy is obsolete.\n");
if (ptlrpcd_partner_group_size == 0) {
switch (ptlrpcd_bind_policy) {
case 1: /* PDB_POLICY_NONE */
case 2: /* PDB_POLICY_FULL */
ptlrpcd_partner_group_size = 1;
break;
case 3: /* PDB_POLICY_PAIR */
ptlrpcd_partner_group_size = 2;
break;
case 4: /* PDB_POLICY_NEIGHBOR */
#ifdef CONFIG_NUMA
ptlrpcd_partner_group_size = -1; /* CPT */
#else
ptlrpcd_partner_group_size = 3; /* Triplets */
#endif
break;
default: /* Illegal value, use the default. */
ptlrpcd_partner_group_size = 2;
break;
}
CWARN("Setting ptlrpcd_partner_group_size = %d\n",
ptlrpcd_partner_group_size);
} else {
CWARN("ptlrpcd_partner_group_size is also set!\n");
}
}
if (ptlrpcd_partner_group_size == 0)
ptlrpcd_partner_group_size = 2;
else if (ptlrpcd_partner_group_size < 0)
ptlrpcd_partner_group_size = -1;
else if (ptlrpcd_per_cpt_max > 0 &&
ptlrpcd_partner_group_size > ptlrpcd_per_cpt_max)
ptlrpcd_partner_group_size = ptlrpcd_per_cpt_max;
/*
* Start the recovery thread first.
*/
set_bit(LIOD_RECOVERY, &ptlrpcd_rcv.pc_flags);
ptlrpcd_ctl_init(&ptlrpcd_rcv, -1, CFS_CPT_ANY);
rc = ptlrpcd_start(&ptlrpcd_rcv);
if (rc < 0)
GOTO(out, rc);
for (i = 0; i < ncpts; i++) {
if (cpts == NULL)
cpt = i;
else
cpt = cpts[i];
nthreads = cfs_cpt_weight(cptable, cpt);
if (ptlrpcd_per_cpt_max > 0 && ptlrpcd_per_cpt_max < nthreads)
nthreads = ptlrpcd_per_cpt_max;
if (nthreads < 2)
nthreads = 2;
if (ptlrpcd_partner_group_size <= 0) {
groupsize = nthreads;
} else if (nthreads <= ptlrpcd_partner_group_size) {
groupsize = nthreads;
} else {
groupsize = ptlrpcd_partner_group_size;
if (nthreads % groupsize != 0)
nthreads += groupsize - (nthreads % groupsize);
}
size = offsetof(struct ptlrpcd, pd_threads[nthreads]);
OBD_CPT_ALLOC(pd, cptable, cpt, size);
if (!pd)
GOTO(out, rc = -ENOMEM);
pd->pd_size = size;
pd->pd_index = i;
pd->pd_cpt = cpt;
pd->pd_cursor = 0;
pd->pd_nthreads = nthreads;
pd->pd_groupsize = groupsize;
ptlrpcds[i] = pd;
/*
* The ptlrpcd threads in a partner group can access
* each other's struct ptlrpcd_ctl, so these must be
* initialized before any thead is started.
*/
for (j = 0; j < nthreads; j++) {
ptlrpcd_ctl_init(&pd->pd_threads[j], j, cpt);
rc = ptlrpcd_partners(pd, j);
if (rc < 0)
GOTO(out, rc);
}
/* XXX: We start nthreads ptlrpc daemons on this cpt.
* Each of them can process any non-recovery
* async RPC to improve overall async RPC
* efficiency.
*
* But there are some issues with async I/O RPCs
* and async non-I/O RPCs processed in the same
* set under some cases. The ptlrpcd may be
* blocked by some async I/O RPC(s), then will
* cause other async non-I/O RPC(s) can not be
* processed in time.
*
* Maybe we should distinguish blocked async RPCs
* from non-blocked async RPCs, and process them
* in different ptlrpcd sets to avoid unnecessary
* dependency. But how to distribute async RPCs
* load among all the ptlrpc daemons becomes
* another trouble.
*/
for (j = 0; j < nthreads; j++) {
rc = ptlrpcd_start(&pd->pd_threads[j]);
if (rc < 0)
GOTO(out, rc);
}
}
out:
if (cpts != NULL)
cfs_expr_list_values_free(cpts, ncpts);
if (rc != 0)
ptlrpcd_fini();
RETURN(rc);
}
int ptlrpcd_addref(void)
{
int rc = 0;
ENTRY;
mutex_lock(&ptlrpcd_mutex);
if (++ptlrpcd_users == 1) {
rc = ptlrpcd_init();
if (rc < 0)
ptlrpcd_users--;
}
mutex_unlock(&ptlrpcd_mutex);
RETURN(rc);
}
EXPORT_SYMBOL(ptlrpcd_addref);
void ptlrpcd_decref(void)
{
mutex_lock(&ptlrpcd_mutex);
if (--ptlrpcd_users == 0)
ptlrpcd_fini();
mutex_unlock(&ptlrpcd_mutex);
}
EXPORT_SYMBOL(ptlrpcd_decref);
/** @} ptlrpcd */
