From: William Lee Irwin III <wli@holomorphy.com>
It appears that init_idle() and fork_by_hand() could be combined into a
single method that calls init_idle() on behalf of the caller.
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/arch/alpha/kernel/smp.c | 14 +-------------
25-akpm/arch/i386/kernel/smpboot.c | 20 +-------------------
25-akpm/arch/i386/mach-voyager/voyager_smp.c | 18 +-----------------
25-akpm/arch/ia64/kernel/smpboot.c | 27 ++++++---------------------
25-akpm/arch/mips/kernel/smp.c | 18 +-----------------
25-akpm/arch/parisc/kernel/smp.c | 22 +---------------------
25-akpm/arch/ppc/kernel/smp.c | 7 +------
25-akpm/arch/ppc64/kernel/smp.c | 10 +---------
25-akpm/arch/s390/kernel/smp.c | 11 +----------
25-akpm/arch/sh/kernel/smp.c | 7 +------
25-akpm/arch/sparc/kernel/sun4d_smp.c | 11 +----------
25-akpm/arch/sparc64/kernel/smp.c | 9 +--------
25-akpm/arch/x86_64/kernel/smpboot.c | 18 +-----------------
25-akpm/include/linux/sched.h | 2 +-
25-akpm/init/main.c | 9 ---------
25-akpm/kernel/fork.c | 16 +++++++++++++++-
25-akpm/kernel/sched.c | 8 ++++++++
arch/um/kernel/smp.c | 0
18 files changed, 42 insertions(+), 185 deletions(-)
diff -puN arch/alpha/kernel/smp.c~sched-init_idle-fork_by_hand-consolidation arch/alpha/kernel/smp.c
--- 25/arch/alpha/kernel/smp.c~sched-init_idle-fork_by_hand-consolidation 2004-08-15 22:47:26.342841064 -0700
+++ 25-akpm/arch/alpha/kernel/smp.c 2004-08-15 22:47:26.385834528 -0700
@@ -411,15 +411,6 @@ secondary_cpu_start(int cpuid, struct ta
return 0;
}
-static struct task_struct * __init
-fork_by_hand(void)
-{
- /* Don't care about the contents of regs since we'll never
- reschedule the forked task. */
- struct pt_regs regs;
- return copy_process(CLONE_VM|CLONE_IDLETASK, 0, ®s, 0, NULL, NULL);
-}
-
/*
* Bring one cpu online.
*/
@@ -435,13 +426,10 @@ smp_boot_one_cpu(int cpuid)
the other task-y sort of data structures set up like we
wish. We can't use kernel_thread since we must avoid
rescheduling the child. */
- idle = fork_by_hand();
+ idle = fork_idle(cpuid);
if (IS_ERR(idle))
panic("failed fork for CPU %d", cpuid);
- init_idle(idle, cpuid);
- unhash_process(idle);
-
DBGS(("smp_boot_one_cpu: CPU %d state 0x%lx flags 0x%lx\n",
cpuid, idle->state, idle->flags));
diff -puN arch/i386/kernel/smpboot.c~sched-init_idle-fork_by_hand-consolidation arch/i386/kernel/smpboot.c
--- 25/arch/i386/kernel/smpboot.c~sched-init_idle-fork_by_hand-consolidation 2004-08-15 22:47:26.344840760 -0700
+++ 25-akpm/arch/i386/kernel/smpboot.c 2004-08-15 22:47:26.387834224 -0700
@@ -496,16 +496,6 @@ extern struct {
unsigned short ss;
} stack_start;
-static struct task_struct * __init fork_by_hand(void)
-{
- struct pt_regs regs;
- /*
- * don't care about the eip and regs settings since
- * we'll never reschedule the forked task.
- */
- return copy_process(CLONE_VM|CLONE_IDLETASK, 0, ®s, 0, NULL, NULL);
-}
-
#ifdef CONFIG_NUMA
/* which logical CPUs are on which nodes */
@@ -801,18 +791,10 @@ static int __init do_boot_cpu(int apicid
* We can't use kernel_thread since we must avoid to
* reschedule the child.
*/
- idle = fork_by_hand();
+ idle = fork_idle(cpu);
if (IS_ERR(idle))
panic("failed fork for CPU %d", cpu);
-
- /* Make this the idle thread */
- init_idle(idle, cpu);
-
idle->thread.eip = (unsigned long) start_secondary;
-
- /* Remove it from the pidhash */
- unhash_process(idle);
-
/* start_eip had better be page-aligned! */
start_eip = setup_trampoline();
diff -puN arch/i386/mach-voyager/voyager_smp.c~sched-init_idle-fork_by_hand-consolidation arch/i386/mach-voyager/voyager_smp.c
--- 25/arch/i386/mach-voyager/voyager_smp.c~sched-init_idle-fork_by_hand-consolidation 2004-08-15 22:47:26.345840608 -0700
+++ 25-akpm/arch/i386/mach-voyager/voyager_smp.c 2004-08-15 22:47:26.388834072 -0700
@@ -523,15 +523,6 @@ start_secondary(void *unused)
return cpu_idle();
}
-static struct task_struct * __init
-fork_by_hand(void)
-{
- struct pt_regs regs;
- /* don't care about the eip and regs settings since we'll
- * never reschedule the forked task. */
- return copy_process(CLONE_VM|CLONE_IDLETASK, 0, ®s, 0, NULL, NULL);
-}
-
/* Routine to kick start the given CPU and wait for it to report ready
* (or timeout in startup). When this routine returns, the requested
@@ -587,17 +578,10 @@ do_boot_cpu(__u8 cpu)
hijack_source.idt.Segment = (start_phys_address >> 4) & 0xFFFF;
cpucount++;
- idle = fork_by_hand();
+ idle = fork_idle(cpu);
if(IS_ERR(idle))
panic("failed fork for CPU%d", cpu);
-
- /* Make this the idle thread */
- init_idle(idle, cpu);
-
idle->thread.eip = (unsigned long) start_secondary;
-
- /* Remove it from the pidhash */
- unhash_process(idle);
/* init_tasks (in sched.c) is indexed logically */
stack_start.esp = (void *) idle->thread.esp;
diff -puN arch/ia64/kernel/smpboot.c~sched-init_idle-fork_by_hand-consolidation arch/ia64/kernel/smpboot.c
--- 25/arch/ia64/kernel/smpboot.c~sched-init_idle-fork_by_hand-consolidation 2004-08-15 22:47:26.347840304 -0700
+++ 25-akpm/arch/ia64/kernel/smpboot.c 2004-08-15 22:47:26.389833920 -0700
@@ -356,19 +356,10 @@ start_secondary (void *unused)
return cpu_idle();
}
-static struct task_struct * __devinit
-fork_by_hand (void)
-{
- /*
- * Don't care about the IP and regs settings since we'll never reschedule the
- * forked task.
- */
- return copy_process(CLONE_VM|CLONE_IDLETASK, 0, 0, 0, NULL, NULL);
-}
-
struct create_idle {
struct task_struct *idle;
struct completion done;
+ int cpu;
};
void
@@ -376,7 +367,7 @@ do_fork_idle(void *_c_idle)
{
struct create_idle *c_idle = _c_idle;
- c_idle->idle = fork_by_hand();
+ c_idle->idle = fork_idle(c_idle->cpu);
complete(&c_idle->done);
}
@@ -384,10 +375,11 @@ static int __devinit
do_boot_cpu (int sapicid, int cpu)
{
int timeout;
- struct create_idle c_idle;
+ struct create_idle c_idle = {
+ .cpu = cpu,
+ .done = COMPLETION_INITIALIZER(c_idle.done),
+ };
DECLARE_WORK(work, do_fork_idle, &c_idle);
-
- init_completion(&c_idle.done);
/*
* We can't use kernel_thread since we must avoid to reschedule the child.
*/
@@ -400,13 +392,6 @@ do_boot_cpu (int sapicid, int cpu)
if (IS_ERR(c_idle.idle))
panic("failed fork for CPU %d", cpu);
-
- /* Make this the idle thread */
- init_idle(c_idle.idle, cpu);
-
- /* Remove it from the pidhash */
- unhash_process(c_idle.idle);
-
task_for_booting_cpu = c_idle.idle;
Dprintk("Sending wakeup vector %lu to AP 0x%x/0x%x.\n", ap_wakeup_vector, cpu, sapicid);
diff -puN arch/mips/kernel/smp.c~sched-init_idle-fork_by_hand-consolidation arch/mips/kernel/smp.c
--- 25/arch/mips/kernel/smp.c~sched-init_idle-fork_by_hand-consolidation 2004-08-15 22:47:26.348840152 -0700
+++ 25-akpm/arch/mips/kernel/smp.c 2004-08-15 22:47:26.390833768 -0700
@@ -254,16 +254,6 @@ void __devinit smp_prepare_boot_cpu(void
cpu_set(0, cpu_callin_map);
}
-static struct task_struct * __init fork_by_hand(void)
-{
- struct pt_regs regs;
- /*
- * don't care about the eip and regs settings since
- * we'll never reschedule the forked task.
- */
- return copy_process(CLONE_VM|CLONE_IDLETASK, 0, ®s, 0, NULL, NULL);
-}
-
/*
* Startup the CPU with this logical number
*/
@@ -275,16 +265,10 @@ static int __init do_boot_cpu(int cpu)
* The following code is purely to make sure
* Linux can schedule processes on this slave.
*/
- idle = fork_by_hand();
+ idle = fork_idle(cpu);
if (IS_ERR(idle))
panic("failed fork for CPU %d\n", cpu);
- /* Make this the idle thread */
- init_idle(idle, cpu);
-
- /* Remove it from the pidhash */
- unhash_process(idle);
-
prom_boot_secondary(cpu, idle);
/* XXXKW timeout */
diff -puN arch/parisc/kernel/smp.c~sched-init_idle-fork_by_hand-consolidation arch/parisc/kernel/smp.c
--- 25/arch/parisc/kernel/smp.c~sched-init_idle-fork_by_hand-consolidation 2004-08-15 22:47:26.349840000 -0700
+++ 25-akpm/arch/parisc/kernel/smp.c 2004-08-15 22:47:26.390833768 -0700
@@ -486,24 +486,6 @@ void __init smp_callin(void)
}
/*
- * Create the idle task for a new Slave CPU. DO NOT use kernel_thread()
- * because that could end up calling schedule(). If it did, the new idle
- * task could get scheduled before we had a chance to remove it from the
- * run-queue...
- */
-static struct task_struct *fork_by_hand(void)
-{
- struct pt_regs regs;
-
- /*
- * don't care about the regs settings since
- * we'll never reschedule the forked task.
- */
- return copy_process(CLONE_VM|CLONE_IDLETASK, 0, ®s, 0, NULL, NULL);
-}
-
-
-/*
* Bring one cpu online.
*/
int __init smp_boot_one_cpu(int cpuid)
@@ -521,12 +503,10 @@ int __init smp_boot_one_cpu(int cpuid)
* Sheesh . . .
*/
- idle = fork_by_hand();
if (IS_ERR(idle))
panic("SMP: fork failed for CPU:%d", cpuid);
- init_idle(idle, cpuid);
- unhash_process(idle);
+ idle = fork_idle(cpunum);
idle->thread_info->cpu = cpuid;
/* Let _start know what logical CPU we're booting
diff -puN arch/ppc64/kernel/smp.c~sched-init_idle-fork_by_hand-consolidation arch/ppc64/kernel/smp.c
--- 25/arch/ppc64/kernel/smp.c~sched-init_idle-fork_by_hand-consolidation 2004-08-15 22:47:26.351839696 -0700
+++ 25-akpm/arch/ppc64/kernel/smp.c 2004-08-15 22:47:26.391833616 -0700
@@ -799,20 +799,12 @@ static void __devinit smp_store_cpu_info
static void __init smp_create_idle(unsigned int cpu)
{
- struct pt_regs regs;
struct task_struct *p;
/* create a process for the processor */
- /* only regs.msr is actually used, and 0 is OK for it */
- memset(®s, 0, sizeof(struct pt_regs));
- p = copy_process(CLONE_VM | CLONE_IDLETASK,
- 0, ®s, 0, NULL, NULL);
+ p = fork_idle(cpu);
if (IS_ERR(p))
panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p));
-
- init_idle(p, cpu);
- unhash_process(p);
-
paca[cpu].__current = p;
current_set[cpu] = p->thread_info;
}
diff -puN arch/ppc/kernel/smp.c~sched-init_idle-fork_by_hand-consolidation arch/ppc/kernel/smp.c
--- 25/arch/ppc/kernel/smp.c~sched-init_idle-fork_by_hand-consolidation 2004-08-15 22:47:26.352839544 -0700
+++ 25-akpm/arch/ppc/kernel/smp.c 2004-08-15 22:47:26.392833464 -0700
@@ -364,20 +364,15 @@ int __devinit start_secondary(void *unus
int __cpu_up(unsigned int cpu)
{
- struct pt_regs regs;
struct task_struct *p;
char buf[32];
int c;
/* create a process for the processor */
/* only regs.msr is actually used, and 0 is OK for it */
- memset(®s, 0, sizeof(struct pt_regs));
- p = copy_process(CLONE_VM|CLONE_IDLETASK, 0, ®s, 0, NULL, NULL);
+ p = fork_idle(cpu);
if (IS_ERR(p))
panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p));
- init_idle(p, cpu);
- unhash_process(p);
-
secondary_ti = p->thread_info;
p->thread_info->cpu = cpu;
diff -puN arch/s390/kernel/smp.c~sched-init_idle-fork_by_hand-consolidation arch/s390/kernel/smp.c
--- 25/arch/s390/kernel/smp.c~sched-init_idle-fork_by_hand-consolidation 2004-08-15 22:47:26.354839240 -0700
+++ 25-akpm/arch/s390/kernel/smp.c 2004-08-15 22:47:26.393833312 -0700
@@ -562,24 +562,15 @@ int __devinit start_secondary(void *cpuv
static void __init smp_create_idle(unsigned int cpu)
{
- struct pt_regs regs;
struct task_struct *p;
/*
* don't care about the psw and regs settings since we'll never
* reschedule the forked task.
*/
- memset(®s, 0, sizeof(struct pt_regs));
- p = copy_process(CLONE_VM | CLONE_IDLETASK, 0, ®s, 0, NULL, NULL);
+ p = fork_idle(cpu);
if (IS_ERR(p))
panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p));
-
- /* Make this the idle thread */
- init_idle(p, cpu);
-
- /* Remove it from the pidhash */
- unhash_process(p);
-
current_set[cpu] = p;
}
diff -puN arch/sh/kernel/smp.c~sched-init_idle-fork_by_hand-consolidation arch/sh/kernel/smp.c
--- 25/arch/sh/kernel/smp.c~sched-init_idle-fork_by_hand-consolidation 2004-08-15 22:47:26.355839088 -0700
+++ 25-akpm/arch/sh/kernel/smp.c 2004-08-15 22:47:26.393833312 -0700
@@ -98,17 +98,12 @@ void __devinit smp_prepare_boot_cpu(void
int __cpu_up(unsigned int cpu)
{
struct task_struct *tsk;
- struct pt_regs regs;
- memset(®s, 0, sizeof(struct pt_regs));
- tsk = copy_process(CLONE_VM | CLONE_IDLETASK, 0, ®s, 0, 0, 0);
+ tsk = fork_idle(cpu);
if (IS_ERR(tsk))
panic("Failed forking idle task for cpu %d\n", cpu);
- init_idle(tsk, cpu);
- unhash_process(tsk);
-
tsk->thread_info->cpu = cpu;
cpu_set(cpu, cpu_online_map);
diff -puN arch/sparc64/kernel/smp.c~sched-init_idle-fork_by_hand-consolidation arch/sparc64/kernel/smp.c
--- 25/arch/sparc64/kernel/smp.c~sched-init_idle-fork_by_hand-consolidation 2004-08-15 22:47:26.356838936 -0700
+++ 25-akpm/arch/sparc64/kernel/smp.c 2004-08-15 22:47:26.394833160 -0700
@@ -303,14 +303,7 @@ static int __devinit smp_boot_one_cpu(un
struct task_struct *p;
int timeout, ret, cpu_node;
- kernel_thread(NULL, NULL, CLONE_IDLETASK);
-
- p = prev_task(&init_task);
-
- init_idle(p, cpu);
-
- unhash_process(p);
-
+ p = fork_idle(cpu);
callin_flag = 0;
cpu_new_thread = p->thread_info;
cpu_set(cpu, cpu_callout_map);
diff -puN arch/sparc/kernel/sun4d_smp.c~sched-init_idle-fork_by_hand-consolidation arch/sparc/kernel/sun4d_smp.c
--- 25/arch/sparc/kernel/sun4d_smp.c~sched-init_idle-fork_by_hand-consolidation 2004-08-15 22:47:26.358838632 -0700
+++ 25-akpm/arch/sparc/kernel/sun4d_smp.c 2004-08-15 22:47:26.395833008 -0700
@@ -201,18 +201,9 @@ void __init smp4d_boot_cpus(void)
int no;
/* Cook up an idler for this guy. */
- kernel_thread(start_secondary, NULL, CLONE_IDLETASK);
-
+ p = fork_idle(p, cpu);
cpucount++;
-
- p = prev_task(&init_task);
-
- init_idle(p, i);
-
current_set[i] = p->thread_info;
-
- unhash_process(p);
-
for (no = 0; !cpu_find_by_instance(no, NULL, &mid)
&& mid != i; no++) ;
diff -puN arch/um/kernel/smp.c~sched-init_idle-fork_by_hand-consolidation arch/um/kernel/smp.c
diff -puN arch/x86_64/kernel/smpboot.c~sched-init_idle-fork_by_hand-consolidation arch/x86_64/kernel/smpboot.c
--- 25/arch/x86_64/kernel/smpboot.c~sched-init_idle-fork_by_hand-consolidation 2004-08-15 22:47:26.376835896 -0700
+++ 25-akpm/arch/x86_64/kernel/smpboot.c 2004-08-15 22:47:26.396832856 -0700
@@ -392,16 +392,6 @@ void __init start_secondary(void)
extern volatile unsigned long init_rsp;
extern void (*initial_code)(void);
-static struct task_struct * __init fork_by_hand(void)
-{
- struct pt_regs regs;
- /*
- * don't care about the eip and regs settings since
- * we'll never reschedule the forked task.
- */
- return copy_process(CLONE_VM|CLONE_IDLETASK, 0, ®s, 0, NULL, NULL);
-}
-
#if APIC_DEBUG
static inline void inquire_remote_apic(int apicid)
{
@@ -575,17 +565,11 @@ static void __init do_boot_cpu (int apic
* We can't use kernel_thread since we must avoid to
* reschedule the child.
*/
- idle = fork_by_hand();
+ idle = fork_idle(cpu);
if (IS_ERR(idle))
panic("failed fork for CPU %d", cpu);
x86_cpu_to_apicid[cpu] = apicid;
- /* Make this the idle thread */
- init_idle(idle,cpu);
-
- /* Remove it from the pidhash */
- unhash_process(idle);
-
cpu_pda[cpu].pcurrent = idle;
start_rip = setup_trampoline();
diff -puN include/linux/sched.h~sched-init_idle-fork_by_hand-consolidation include/linux/sched.h
--- 25/include/linux/sched.h~sched-init_idle-fork_by_hand-consolidation 2004-08-15 22:47:26.377835744 -0700
+++ 25-akpm/include/linux/sched.h 2004-08-15 22:47:26.397832704 -0700
@@ -788,7 +788,7 @@ extern task_t *child_reaper;
extern int do_execve(char *, char __user * __user *, char __user * __user *, struct pt_regs *);
extern long do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *);
-extern struct task_struct * copy_process(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *);
+task_t *fork_idle(int);
extern void set_task_comm(struct task_struct *tsk, char *from);
extern void get_task_comm(char *to, struct task_struct *tsk);
diff -puN init/main.c~sched-init_idle-fork_by_hand-consolidation init/main.c
--- 25/init/main.c~sched-init_idle-fork_by_hand-consolidation 2004-08-15 22:47:26.378835592 -0700
+++ 25-akpm/init/main.c 2004-08-15 22:47:26.397832704 -0700
@@ -470,15 +470,6 @@ asmlinkage void __init start_kernel(void
* time - but meanwhile we still have a functioning scheduler.
*/
sched_init();
-
- /*
- * Make us the idle thread. Technically, schedule() should not be
- * called from this thread, however somewhere below it might be,
- * but because we are the idle thread, we just pick up running again
- * when this runqueue becomes "idle".
- */
- init_idle(current, smp_processor_id());
-
build_all_zonelists();
page_alloc_init();
trap_init();
diff -puN kernel/fork.c~sched-init_idle-fork_by_hand-consolidation kernel/fork.c
--- 25/kernel/fork.c~sched-init_idle-fork_by_hand-consolidation 2004-08-15 22:47:26.380835288 -0700
+++ 25-akpm/kernel/fork.c 2004-08-15 22:47:26.398832552 -0700
@@ -864,7 +864,7 @@ asmlinkage long sys_set_tid_address(int
* parts of the process environment (as per the clone
* flags). The actual kick-off is left to the caller.
*/
-struct task_struct *copy_process(unsigned long clone_flags,
+static task_t *copy_process(unsigned long clone_flags,
unsigned long stack_start,
struct pt_regs *regs,
unsigned long stack_size,
@@ -1152,6 +1152,20 @@ bad_fork_free:
goto fork_out;
}
+task_t * __init fork_idle(int cpu)
+{
+ task_t *task;
+ struct pt_regs regs;
+
+ memset(®s, 0, sizeof(struct pt_regs));
+ task = copy_process(CLONE_VM|CLONE_IDLETASK, 0, ®s, 0, NULL, NULL);
+ if (!task)
+ return ERR_PTR(-ENOMEM);
+ init_idle(task, cpu);
+ unhash_process(task);
+ return task;
+}
+
static inline int fork_traceflag (unsigned clone_flags)
{
if (clone_flags & (CLONE_UNTRACED | CLONE_IDLETASK))
diff -puN kernel/sched.c~sched-init_idle-fork_by_hand-consolidation kernel/sched.c
--- 25/kernel/sched.c~sched-init_idle-fork_by_hand-consolidation 2004-08-15 22:47:26.382834984 -0700
+++ 25-akpm/kernel/sched.c 2004-08-15 22:47:26.402831944 -0700
@@ -4535,6 +4535,14 @@ void __init sched_init(void)
*/
atomic_inc(&init_mm.mm_count);
enter_lazy_tlb(&init_mm, current);
+
+ /*
+ * Make us the idle thread. Technically, schedule() should not be
+ * called from this thread, however somewhere below it might be,
+ * but because we are the idle thread, we just pick up running again
+ * when this runqueue becomes "idle".
+ */
+ init_idle(current, smp_processor_id());
}
#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
_