I tried a version of __daemonize in 2.4. It panics in
schedule()
prepare_to_switch();
{
struct mm_struct *mm = next->mm;
struct mm_struct *oldmm = prev->active_mm;
if (!mm) {
if (next->active_mm) BUG();
I got hit by the BUG() in 2.4, I think prepare_to_switch has
moved to specific archs in 2.5. A quick look showed that
this issue no longer exists in 2.5.
Comments,
Balbir Singh.
|-----Original Message-----
|From: linux-kernel-owner@vger.kernel.org
|[mailto:linux-kernel-owner@vger.kernel.org]On Behalf Of Rusty Russell
|Sent: Thursday, May 09, 2002 2:20 PM
|To: torvalds@transmeta.com
|Cc: linux-kernel@vger.kernel.org
|Subject: [PATCH] Hotplug CPU prep III: daemonize idle tasks
|
|
|This patch introduces __daemonize(task), so idle tasks can be detached
|after cloning (required for late creation of idle tasks).
|
|This is independent of the last two patches.
|
|Name: Daemonize idle task
|Author: Rusty Russell
|
|D: This patch allows daemonize() to be called on another process (if
|D: not started yet), and calls it on the idle task.
|
|diff -urN -I \$.*\$ --exclude TAGS -X
|/home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal
|working-2.5.14-dofork+clonepid/include/linux/sched.h
|tmp/include/linux/sched.h
|--- working-2.5.14-dofork+clonepid/include/linux/sched.h Thu
|May 9 18:25:21 2002
|+++ tmp/include/linux/sched.h Thu May 9 18:36:17 2002
|@@ -654,7 +654,12 @@
| extern void exit_sighand(struct task_struct *);
|
| extern void reparent_to_init(void);
|-extern void daemonize(void);
|+extern void __daemonize(struct task_struct *);
|+static inline void daemonize(void)
|+{
|+ __daemonize(current);
|+}
|+
| extern task_t *child_reaper;
|
| extern int do_execve(char *, char **, char **, struct pt_regs *);
|diff -urN -I \$.*\$ --exclude TAGS -X
|/home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal
|working-2.5.14-dofork+clonepid/kernel/exit.c tmp/kernel/exit.c
|--- working-2.5.14-dofork+clonepid/kernel/exit.c Mon Apr 29
|16:00:29 2002
|+++ tmp/kernel/exit.c Thu May 9 18:36:17 2002
|@@ -201,32 +201,30 @@
| * Put all the gunge required to become a kernel thread without
| * attached user resources in one place where it belongs.
| */
|-
|-void daemonize(void)
|+void __daemonize(struct task_struct *tsk)
| {
| struct fs_struct *fs;
|
|-
| /*
| * If we were started as result of loading a module, close
|all of the
| * user space pages. We don't need them, and if we didn't
|close them
| * they would be locked into memory.
| */
|- exit_mm(current);
|+ exit_mm(tsk);
|
|- current->session = 1;
|- current->pgrp = 1;
|- current->tty = NULL;
|+ tsk->session = 1;
|+ tsk->pgrp = 1;
|+ tsk->tty = NULL;
|
| /* Become as one with the init task */
|
|- exit_fs(current); /* current->fs->count--; */
|+ exit_fs(tsk); /* current->fs->count--; */
| fs = init_task.fs;
|- current->fs = fs;
|+ tsk->fs = fs;
| atomic_inc(&fs->count);
|- exit_files(current);
|- current->files = init_task.files;
|- atomic_inc(¤t->files->count);
|+ exit_files(tsk);
|+ tsk->files = init_task.files;
|+ atomic_inc(&tsk->files->count);
| }
|
| /*
|diff -urN -I \$.*\$ --exclude TAGS -X
|/home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal
|working-2.5.14-dofork+clonepid/kernel/sched.c tmp/kernel/sched.c
|--- working-2.5.14-dofork+clonepid/kernel/sched.c Wed May 1
|15:09:29 2002
|+++ tmp/kernel/sched.c Thu May 9 18:45:17 2002
|@@ -1555,6 +1555,8 @@
| runqueue_t *idle_rq = cpu_rq(cpu), *rq =
|cpu_rq(idle->thread_info->cpu);
| unsigned long flags;
|
|+ if (idle != &init_task)
|+ __daemonize(idle);
| __save_flags(flags);
| __cli();
| double_rq_lock(idle_rq, rq);
|
|--
| Anyone who quotes me in their sig is an idiot. -- Rusty Russell.
|-
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This archive was generated by hypermail 2b29 : Tue May 14 2002 - 12:00:11 EST