From: Christoph Hellwig <hch@lst.de>
ia64 doesn't like Linus thread_info on the stack + slabified
task_struct, add a flag to allow architectures request the old scheme.
(David, could you review this carefully, I tried to make it more
generic but maybe I got something wrong for the ia64 case..)
arch/ia64/kernel/process.c | 26 ---------
include/asm-ia64/thread_info.h | 6 +-
kernel/fork.c | 110 ++++++++++++++++++++++++-----------------
3 files changed, 70 insertions(+), 72 deletions(-)
diff -puN arch/ia64/kernel/process.c~thread-info-in-task_struct arch/ia64/kernel/process.c
--- 25/arch/ia64/kernel/process.c~thread-info-in-task_struct 2003-05-31 19:56:54.000000000 -0700
+++ 25-akpm/arch/ia64/kernel/process.c 2003-05-31 19:56:54.000000000 -0700
@@ -740,29 +740,3 @@ machine_power_off (void)
pm_power_off();
machine_halt();
}
-
-void __init
-init_task_struct_cache (void)
-{
-}
-
-struct task_struct *
-dup_task_struct(struct task_struct *orig)
-{
- struct task_struct *tsk;
-
- tsk = (void *) __get_free_pages(GFP_KERNEL, KERNEL_STACK_SIZE_ORDER);
- if (!tsk)
- return NULL;
-
- memcpy(tsk, orig, sizeof(struct task_struct) + sizeof(struct thread_info));
- tsk->thread_info = (struct thread_info *) ((char *) tsk + IA64_TASK_SIZE);
- atomic_set(&tsk->usage, 2);
- return tsk;
-}
-
-void
-free_task_struct (struct task_struct *tsk)
-{
- free_pages((unsigned long) tsk, KERNEL_STACK_SIZE_ORDER);
-}
diff -puN include/asm-ia64/thread_info.h~thread-info-in-task_struct include/asm-ia64/thread_info.h
--- 25/include/asm-ia64/thread_info.h~thread-info-in-task_struct 2003-05-31 19:56:54.000000000 -0700
+++ 25-akpm/include/asm-ia64/thread_info.h 2003-05-31 19:56:54.000000000 -0700
@@ -34,8 +34,10 @@ struct thread_info {
struct restart_block restart_block;
};
-#define INIT_THREAD_SIZE /* tell sched.h not to declare the thread_union */
-#define THREAD_SIZE KERNEL_STACK_SIZE
+#define __HAVE_THREAD_INFO_IN_TASK_STRUCT 1
+/* tell sched.h not to declare the thread_union */
+#define INIT_THREAD_SIZE
+#define THREAD_SIZE KERNEL_STACK_SIZE
#define INIT_THREAD_INFO(ti) \
{ \
diff -puN kernel/fork.c~thread-info-in-task_struct kernel/fork.c
--- 25/kernel/fork.c~thread-info-in-task_struct 2003-05-31 19:56:54.000000000 -0700
+++ 25-akpm/kernel/fork.c 2003-05-31 19:56:54.000000000 -0700
@@ -38,8 +38,6 @@
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
-static kmem_cache_t *task_struct_cachep;
-
extern int copy_semundo(unsigned long clone_flags, struct task_struct *tsk);
extern void exit_semundo(struct task_struct *tsk);
@@ -55,13 +53,6 @@ DEFINE_PER_CPU(unsigned long, process_co
rwlock_t tasklist_lock __cacheline_aligned = RW_LOCK_UNLOCKED; /* outer */
-/*
- * A per-CPU task cache - this relies on the fact that
- * the very last portion of sys_exit() is executed with
- * preemption turned off.
- */
-static task_t *task_cache[NR_CPUS] __cacheline_aligned;
-
int nr_processes(void)
{
int cpu;
@@ -74,6 +65,69 @@ int nr_processes(void)
return total;
}
+#ifdef __HAVE_THREAD_INFO_IN_TASK_STRUCT
+static inline struct task_struct *dup_task_struct(struct task_struct *orig)
+{
+ struct task_struct *tsk;
+
+ tsk = (void *)__get_free_pages(GFP_KERNEL, KERNEL_STACK_SIZE_ORDER);
+ if (likely(tsk != NULL)) {
+ memcpy(tsk, orig, sizeof(*tsk) + sizeof(struct thread_info));
+ tsk->thread_info = (struct thread_info *)(tsk + 1);
+ atomic_set(&tsk->usage, 2);
+ }
+
+ return tsk;
+}
+
+static inline void
+free_task_struct (struct task_struct *tsk)
+{
+ free_pages((unsigned long)tsk, KERNEL_STACK_SIZE_ORDER);
+}
+#else
+/*
+ * A per-CPU task cache - this relies on the fact that
+ * the very last portion of sys_exit() is executed with
+ * preemption turned off.
+ */
+static struct task_struct *task_cache[NR_CPUS] __cacheline_aligned;
+static kmem_cache_t *task_struct_cachep;
+
+struct task_struct *dup_task_struct(struct task_struct *orig)
+{
+ struct task_struct *tsk;
+ struct thread_info *ti;
+ int cpu = get_cpu();
+
+ prepare_to_copy(orig);
+
+ tsk = task_cache[cpu];
+ task_cache[cpu] = NULL;
+ put_cpu();
+ if (!tsk) {
+ ti = alloc_thread_info();
+ if (!ti)
+ return NULL;
+
+ tsk = kmem_cache_alloc(task_struct_cachep, GFP_KERNEL);
+ if (!tsk) {
+ free_thread_info(ti);
+ return NULL;
+ }
+ } else
+ ti = tsk->thread_info;
+
+ *ti = *orig->thread_info;
+ *tsk = *orig;
+ tsk->thread_info = ti;
+ ti->task = tsk;
+
+ /* One for us, one for whoever does the "release_task()" (usually parent) */
+ atomic_set(&tsk->usage, 2);
+ return tsk;
+}
+
static void free_task_struct(struct task_struct *tsk)
{
/*
@@ -97,6 +151,7 @@ static void free_task_struct(struct task
put_cpu();
}
}
+#endif /* __HAVE_THREAD_INFO_IN_TASK_STRUCT */
void __put_task_struct(struct task_struct *tsk)
{
@@ -186,6 +241,7 @@ int autoremove_wake_function(wait_queue_
void __init fork_init(unsigned long mempages)
{
+#ifndef __HAVE_THREAD_INFO_IN_TASK_STRUCT
/* create a slab on which task_structs can be allocated */
task_struct_cachep =
kmem_cache_create("task_struct",
@@ -193,7 +249,7 @@ void __init fork_init(unsigned long memp
SLAB_MUST_HWCACHE_ALIGN, NULL, NULL);
if (!task_struct_cachep)
panic("fork_init(): cannot create task_struct SLAB cache");
-
+#endif
/*
* The default maximum number of threads is set to a safe
* value: the thread structures can take up at most half
@@ -210,40 +266,6 @@ void __init fork_init(unsigned long memp
init_task.rlim[RLIMIT_NPROC].rlim_max = max_threads/2;
}
-static struct task_struct *dup_task_struct(struct task_struct *orig)
-{
- struct task_struct *tsk;
- struct thread_info *ti;
- int cpu = get_cpu();
-
- prepare_to_copy(orig);
-
- tsk = task_cache[cpu];
- task_cache[cpu] = NULL;
- put_cpu();
- if (!tsk) {
- ti = alloc_thread_info();
- if (!ti)
- return NULL;
-
- tsk = kmem_cache_alloc(task_struct_cachep, GFP_KERNEL);
- if (!tsk) {
- free_thread_info(ti);
- return NULL;
- }
- } else
- ti = tsk->thread_info;
-
- *ti = *orig->thread_info;
- *tsk = *orig;
- tsk->thread_info = ti;
- ti->task = tsk;
-
- /* One for us, one for whoever does the "release_task()" (usually parent) */
- atomic_set(&tsk->usage,2);
- return tsk;
-}
-
#ifdef CONFIG_MMU
static inline int dup_mmap(struct mm_struct * mm, struct mm_struct * oldmm)
{
_