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uti: futex_wait: Use kmalloc area for wait queue

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Change-Id: Ida994c87334f9613bbf5cbda45b6b5474fd4c6be
This commit is contained in:
Shiratori, Takehiro
2019-03-19 18:30:00 +09:00
committed by Masamichi Takagi
parent e1c6e17400
commit bb2589bac4
3 changed files with 53 additions and 41 deletions
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60
kernel/futex.c
View File

@ -87,38 +87,6 @@
unsigned long ihk_mc_get_ns_per_tsc(void);
/**
* struct futex_q - The hashed futex queue entry, one per waiting task
* @task: the task waiting on the futex
* @lock_ptr: the hash bucket lock
* @key: the key the futex is hashed on
* @requeue_pi_key: the requeue_pi target futex key
* @bitset: bitset for the optional bitmasked wakeup
*
* We use this hashed waitqueue, instead of a normal wait_queue_t, so
* we can wake only the relevant ones (hashed queues may be shared).
*
* A futex_q has a woken state, just like tasks have TASK_RUNNING.
* It is considered woken when plist_node_empty(&q->list) || q->lock_ptr == 0.
* The order of wakup is always to make the first condition true, then
* the second.
*
* PI futexes are typically woken before they are removed from the hash list via
* the rt_mutex code. See unqueue_me_pi().
*/
struct futex_q {
struct plist_node list;
struct thread *task;
ihk_spinlock_t *lock_ptr;
union futex_key key;
union futex_key *requeue_pi_key;
uint32_t bitset;
/* Used to wake-up a thread running on a Linux CPU */
void *uti_futex_resp;
};
/*
* Hash buckets are shared by all the futex_keys that hash to the same
* location. Each key may have multiple futex_q structures, one for each task
@ -825,13 +793,22 @@ static int futex_wait(uint32_t __user *uaddr, int fshared,
struct cpu_local_var *clv_override)
{
struct futex_hash_bucket *hb;
struct futex_q q;
int64_t time_remain;
struct futex_q lq;
struct futex_q *q = NULL;
int ret;
if (!bitset)
return -EINVAL;
if (!clv_override) {
q = &lq;
}
else {
q = &cpu_local_var_with_override(current,
clv_override)->futex_q;
}
#ifdef PROFILE_ENABLE
if (cpu_local_var_with_override(current, clv_override)->profile &&
cpu_local_var_with_override(current, clv_override)->profile_start_ts) {
@ -841,24 +818,25 @@ static int futex_wait(uint32_t __user *uaddr, int fshared,
}
#endif
q.bitset = bitset;
q.requeue_pi_key = NULL;
q.uti_futex_resp = cpu_local_var_with_override(uti_futex_resp, clv_override);
q->bitset = bitset;
q->requeue_pi_key = NULL;
q->uti_futex_resp = cpu_local_var_with_override(uti_futex_resp,
clv_override);
retry:
/* Prepare to wait on uaddr. */
ret = futex_wait_setup(uaddr, val, fshared, &q, &hb, clv_override);
ret = futex_wait_setup(uaddr, val, fshared, q, &hb, clv_override);
if (ret) {
uti_dkprintf("%s: tid=%d futex_wait_setup returns zero, no need to sleep\n", __FUNCTION__, cpu_local_var_with_override(current, clv_override)->tid);
goto out;
}
/* queue_me and wait for wakeup, timeout, or a signal. */
time_remain = futex_wait_queue_me(hb, &q, timeout, clv_override);
time_remain = futex_wait_queue_me(hb, q, timeout, clv_override);
/* If we were woken (and unqueued), we succeeded, whatever. */
ret = 0;
if (!unqueue_me(&q)) {
if (!unqueue_me(q)) {
uti_dkprintf("%s: tid=%d unqueued\n", __FUNCTION__, cpu_local_var_with_override(current, clv_override)->tid);
goto out_put_key;
}
@ -878,11 +856,11 @@ retry:
}
/* RIKEN: no signals */
put_futex_key(fshared, &q.key);
put_futex_key(fshared, &q->key);
goto retry;
out_put_key:
put_futex_key(fshared, &q.key);
put_futex_key(fshared, &q->key);
out:
#ifdef PROFILE_ENABLE
if (cpu_local_var_with_override(current, clv_override)->profile) {

33
kernel/include/futex.h
View File

@ -94,6 +94,7 @@
#include <list.h>
#include <process.h>
#include <waitq.h>
#include <plist.h>
#ifndef _ASM_X86_FUTEX_H
#define _ASM_X86_FUTEX_H
@ -165,5 +166,37 @@ futex(
);
/**
* struct futex_q - The hashed futex queue entry, one per waiting task
* @task: the task waiting on the futex
* @lock_ptr: the hash bucket lock
* @key: the key the futex is hashed on
* @requeue_pi_key: the requeue_pi target futex key
* @bitset: bitset for the optional bitmasked wakeup
*
* We use this hashed waitqueue, instead of a normal wait_queue_t, so
* we can wake only the relevant ones (hashed queues may be shared).
*
* A futex_q has a woken state, just like tasks have TASK_RUNNING.
* It is considered woken when plist_node_empty(&q->list) || q->lock_ptr == 0.
* The order of wakup is always to make the first condition true, then
* the second.
*
* PI futexes are typically woken before they are removed from the hash list via
* the rt_mutex code. See unqueue_me_pi().
*/
struct futex_q {
struct plist_node list;
struct thread *task;
ihk_spinlock_t *lock_ptr;
union futex_key key;
union futex_key *requeue_pi_key;
uint32_t bitset;
/* Used to wake-up a thread running on a Linux CPU */
void *uti_futex_resp;
};
#endif
#endif

1
kernel/include/process.h
View File

@ -717,6 +717,7 @@ struct thread {
struct uti_attr *mod_clone_arg;
int parent_cpuid;
int uti_refill_tid;
struct futex_q futex_q;
// for performance counter
unsigned long pmc_alloc_map;