sergiotarxz/nuttx
sergiotarxz/nuttx
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sched/sched: There is no need to use sched_[un]lock

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purpose:
1 sched_lock is very time-consuming, and reducing its invocations can improve performance.
2 sched_lock is prone to misuse, and narrowing its scope of use is to prevent people from referencing incorrect code and using it

test:
We can use qemu for testing.
compiling
make distclean -j20; ./tools/configure.sh -l qemu-armv8a:nsh_smp ;make -j20
running
qemu-system-aarch64 -cpu cortex-a53 -smp 4 -nographic -machine virt,virtualization=on,gic-version=3 -net none -chardev stdio,id=con,mux=on -serial chardev:con -mon chardev=con,mode=readline -kernel ./nuttx

We have also tested this patch on other ARM hardware platforms.

Signed-off-by: hujun5 <hujun5@xiaomi.com>
This commit is contained in:
hujun5 2024-04-16 09:36:10 +08:00 committed by Alan Carvalho de Assis
parent 4f1ac5160c
commit 8a6aa5f5bf
4 changed files with 11 additions and 52 deletions
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6
sched/sched/sched_getaffinity.c
View File

@ -69,13 +69,15 @@
int nxsched_get_affinity(pid_t pid, size_t cpusetsize, FAR cpu_set_t *mask)
{
FAR struct tcb_s *tcb;
irqstate_t flags;
int ret;
DEBUGASSERT(cpusetsize == sizeof(cpu_set_t) && mask != NULL);
/* Verify that the PID corresponds to a real task */
sched_lock();
flags = enter_critical_section();
if (pid == 0)
{
tcb = this_task();
@ -97,7 +99,7 @@ int nxsched_get_affinity(pid_t pid, size_t cpusetsize, FAR cpu_set_t *mask)
ret = OK;
}
sched_unlock();
leave_critical_section(flags);
return ret;
}

5
sched/sched/sched_getparam.c
View File

@ -70,6 +70,7 @@ int nxsched_get_param(pid_t pid, FAR struct sched_param *param)
{
FAR struct tcb_s *rtcb;
FAR struct tcb_s *tcb;
irqstate_t flags;
int ret = OK;
if (param == NULL)
@ -93,7 +94,7 @@ int nxsched_get_param(pid_t pid, FAR struct sched_param *param)
{
/* Get the TCB associated with this PID */
sched_lock();
flags = enter_critical_section();
tcb = nxsched_get_tcb(pid);
if (!tcb)
{
@ -137,7 +138,7 @@ int nxsched_get_param(pid_t pid, FAR struct sched_param *param)
#endif
}
sched_unlock();
leave_critical_section(flags);
}
return ret;

22
sched/sched/sched_waitid.c
View File

@ -152,6 +152,7 @@ int waitid(idtype_t idtype, id_t id, FAR siginfo_t *info, int options)
FAR struct child_status_s *child;
bool retains;
#endif
irqstate_t flags;
sigset_t set;
int errcode;
int ret;
@ -198,18 +199,7 @@ int waitid(idtype_t idtype, id_t id, FAR siginfo_t *info, int options)
sigemptyset(&set);
nxsig_addset(&set, SIGCHLD);
/* NOTE: sched_lock() is not enough for SMP
* because the child task is running on another CPU
*/
#ifdef CONFIG_SMP
irqstate_t flags = enter_critical_section();
#else
/* Disable pre-emption so that nothing changes while the loop executes */
sched_lock();
#endif
flags = enter_critical_section();
/* Verify that this task actually has children and that the requested
* TCB is actually a child of this task.
@ -464,20 +454,12 @@ int waitid(idtype_t idtype, id_t id, FAR siginfo_t *info, int options)
}
}
#ifdef CONFIG_SMP
leave_critical_section(flags);
#else
sched_unlock();
#endif
leave_cancellation_point();
return OK;
errout:
#ifdef CONFIG_SMP
leave_critical_section(flags);
#else
sched_unlock();
#endif
leave_cancellation_point();
set_errno(errcode);
return ERROR;

30
sched/sched/sched_waitpid.c
View File

@ -101,13 +101,7 @@ pid_t nxsched_waitpid(pid_t pid, int *stat_loc, int options)
* because the child task is running on another CPU
*/
#ifdef CONFIG_SMP
irqstate_t flags = enter_critical_section();
#else
/* Disable pre-emption so that nothing changes in the following tests */
sched_lock();
#endif
/* Get the TCB corresponding to this PID */
@ -198,12 +192,7 @@ pid_t nxsched_waitpid(pid_t pid, int *stat_loc, int options)
ret = pid;
errout:
#ifdef CONFIG_SMP
leave_critical_section(flags);
#else
sched_unlock();
#endif
return ret;
}
@ -230,6 +219,7 @@ pid_t nxsched_waitpid(pid_t pid, int *stat_loc, int options)
bool retains;
#endif
FAR struct siginfo info;
irqstate_t flags;
sigset_t set;
int ret;
@ -237,18 +227,7 @@ pid_t nxsched_waitpid(pid_t pid, int *stat_loc, int options)
sigemptyset(&set);
nxsig_addset(&set, SIGCHLD);
/* NOTE: sched_lock() is not enough for SMP
* because the child task is running on another CPU
*/
#ifdef CONFIG_SMP
irqstate_t flags = enter_critical_section();
#else
/* Disable pre-emption so that nothing changes while the loop executes */
sched_lock();
#endif
flags = enter_critical_section();
/* Verify that this task actually has children and that the requested PID
* is actually a child of this task.
@ -495,12 +474,7 @@ pid_t nxsched_waitpid(pid_t pid, int *stat_loc, int options)
ret = pid;
errout:
#ifdef CONFIG_SMP
leave_critical_section(flags);
#else
sched_unlock();
#endif
return ret;
}
#endif /* CONFIG_SCHED_HAVE_PARENT */