[rfc,patch] breaking up sched.h

Tim Schmielau
2002-05-24T20:34:07Z

While it's quite common to do "current->foo", every file doing
so needs to #include <linux/sched.h> for the declaration of
task_struct.
In order to reduce the number of #include <linux/sched.h>, I'd propose to
move task_struct to a separate header file (patch below), and include it
from <asm/current.h>.

Other common causes for unnecessary sched.h includes are

request_irq()
free_irq()
suser()
fsuser()
capable()

While the latter three are probably better hosted in
<linux/capability.h>, I'm unsure where to move the former two.
<linux/irq.h> seems quite natural, but it starts with a comment

/*
* Please do not include this file in generic code. There is currently
* no requirement for any architecture to implement anything held
* within this file.
*
* Thanks. --rmk
*/

so that seems to be no-go. Any alternative suggestions?

Tim

--- linux-2.5.17/include/linux/sched.h Tue May 21 07:07:31 2002
+++ linux-2.5.17-jc/include/linux/sched.h Fri May 24 21:53:20 2002
@@ -129,6 +129,7 @@
#ifdef __KERNEL__

#include <linux/spinlock.h>
+#include <linux/task_struct.h>

/*
* This serializes "schedule()" and also protects
@@ -246,125 +247,6 @@
#define INIT_USER (&root_user)

typedef struct prio_array prio_array_t;
-
-struct task_struct {
- volatile long state; /* -1 unrunnable, 0 runnable, >0 stopped */
- struct thread_info *thread_info;
- atomic_t usage;
- unsigned long flags; /* per process flags, defined below */
- unsigned long ptrace;
-
- int lock_depth; /* Lock depth */
-
- int prio, static_prio;
- list_t run_list;
- prio_array_t *array;
-
- unsigned long sleep_avg;
- unsigned long sleep_timestamp;
-
- unsigned long policy;
- unsigned long cpus_allowed;
- unsigned int time_slice;
-
- struct list_head tasks;
-
- struct mm_struct *mm, *active_mm;
- struct list_head local_pages;
-
- unsigned int allocation_order, nr_local_pages;
-
-/* task state */
- struct linux_binfmt *binfmt;
- int exit_code, exit_signal;
- int pdeath_signal; /* The signal sent when the parent dies */
- /* ??? */
- unsigned long personality;
- int did_exec:1;
- pid_t pid;
- pid_t pgrp;
- pid_t tty_old_pgrp;
- pid_t session;
- pid_t tgid;
- /* boolean value for session group leader */
- int leader;
- /*
- * pointers to (original) parent process, youngest child, younger sibling,
- * older sibling, respectively. (p->father can be replaced with
- * p->parent->pid)
- */
- struct task_struct *real_parent; /* real parent process (when being debugged) */
- struct task_struct *parent; /* parent process */
- struct list_head children; /* list of my children */
- struct list_head sibling; /* linkage in my parent's children list */
- struct list_head thread_group;
-
- /* PID hash table linkage. */
- struct task_struct *pidhash_next;
- struct task_struct **pidhash_pprev;
-
- wait_queue_head_t wait_chldexit; /* for wait4() */
- struct completion *vfork_done; /* for vfork() */
-
- unsigned long rt_priority;
- unsigned long it_real_value, it_prof_value, it_virt_value;
- unsigned long it_real_incr, it_prof_incr, it_virt_incr;
- struct timer_list real_timer;
- struct tms times;
- unsigned long start_time;
- long per_cpu_utime[NR_CPUS], per_cpu_stime[NR_CPUS];
-/* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
- unsigned long min_flt, maj_flt, nswap, cmin_flt, cmaj_flt, cnswap;
- int swappable:1;
-/* process credentials */
- uid_t uid,euid,suid,fsuid;
- gid_t gid,egid,sgid,fsgid;
- int ngroups;
- gid_t groups[NGROUPS];
- kernel_cap_t cap_effective, cap_inheritable, cap_permitted;
- int keep_capabilities:1;
- struct user_struct *user;
-/* limits */
- struct rlimit rlim[RLIM_NLIMITS];
- unsigned short used_math;
- char comm[16];
-/* file system info */
- int link_count, total_link_count;
- struct tty_struct *tty; /* NULL if no tty */
- unsigned int locks; /* How many file locks are being held */
-/* ipc stuff */
- struct sysv_sem sysvsem;
-/* CPU-specific state of this task */
- struct thread_struct thread;
-/* filesystem information */
- struct fs_struct *fs;
-/* open file information */
- struct files_struct *files;
-/* namespace */
- struct namespace *namespace;
-/* signal handlers */
- spinlock_t sigmask_lock; /* Protects signal and blocked */
- struct signal_struct *sig;
-
- sigset_t blocked;
- struct sigpending pending;
-
- unsigned long sas_ss_sp;
- size_t sas_ss_size;
- int (*notifier)(void *priv);
- void *notifier_data;
- sigset_t *notifier_mask;
-
-/* Thread group tracking */
- u32 parent_exec_id;
- u32 self_exec_id;
-/* Protection of (de-)allocation: mm, files, fs, tty */
- spinlock_t alloc_lock;
-
-/* journalling filesystem info */
- void *journal_info;
- struct dentry *proc_dentry;
-};

extern void __put_task_struct(struct task_struct *tsk);
#define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)

--- linux-2.5.17/include/linux/task_struct.h Thu Jan 1 01:00:00 1970
+++ linux-2.5.17-jc/include/linux/task_struct.h Fri May 24 21:52:03 2002
@@ -0,0 +1,128 @@
+#ifndef _LINUX_TASK_STRUCT_H
+#define _LINUX_TASK_STRUCT_H
+
+#ifdef __KERNEL__
+
+struct task_struct {
+ volatile long state; /* -1 unrunnable, 0 runnable, >0 stopped */
+ struct thread_info *thread_info;
+ atomic_t usage;
+ unsigned long flags; /* per process flags, defined below */
+ unsigned long ptrace;
+
+ int lock_depth; /* Lock depth */
+
+ int prio, static_prio;
+ list_t run_list;
+ prio_array_t *array;
+
+ unsigned long sleep_avg;
+ unsigned long sleep_timestamp;
+
+ unsigned long policy;
+ unsigned long cpus_allowed;
+ unsigned int time_slice;
+
+ struct list_head tasks;
+
+ struct mm_struct *mm, *active_mm;
+ struct list_head local_pages;
+
+ unsigned int allocation_order, nr_local_pages;
+
+/* task state */
+ struct linux_binfmt *binfmt;
+ int exit_code, exit_signal;
+ int pdeath_signal; /* The signal sent when the parent dies */
+ /* ??? */
+ unsigned long personality;
+ int did_exec:1;
+ pid_t pid;
+ pid_t pgrp;
+ pid_t tty_old_pgrp;
+ pid_t session;
+ pid_t tgid;
+ /* boolean value for session group leader */
+ int leader;
+ /*
+ * pointers to (original) parent process, youngest child, younger sibling,
+ * older sibling, respectively. (p->father can be replaced with
+ * p->parent->pid)
+ */
+ struct task_struct *real_parent; /* real parent process (when being debugged) */
+ struct task_struct *parent; /* parent process */
+ struct list_head children; /* list of my children */
+ struct list_head sibling; /* linkage in my parent's children list */
+ struct list_head thread_group;
+
+ /* PID hash table linkage. */
+ struct task_struct *pidhash_next;
+ struct task_struct **pidhash_pprev;
+
+ wait_queue_head_t wait_chldexit; /* for wait4() */
+ struct completion *vfork_done; /* for vfork() */
+
+ unsigned long rt_priority;
+ unsigned long it_real_value, it_prof_value, it_virt_value;
+ unsigned long it_real_incr, it_prof_incr, it_virt_incr;
+ struct timer_list real_timer;
+ struct tms times;
+ unsigned long start_time;
+ long per_cpu_utime[NR_CPUS], per_cpu_stime[NR_CPUS];
+/* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
+ unsigned long min_flt, maj_flt, nswap, cmin_flt, cmaj_flt, cnswap;
+ int swappable:1;
+/* process credentials */
+ uid_t uid,euid,suid,fsuid;
+ gid_t gid,egid,sgid,fsgid;
+ int ngroups;
+ gid_t groups[NGROUPS];
+ kernel_cap_t cap_effective, cap_inheritable, cap_permitted;
+ int keep_capabilities:1;
+ struct user_struct *user;
+/* limits */
+ struct rlimit rlim[RLIM_NLIMITS];
+ unsigned short used_math;
+ char comm[16];
+/* file system info */
+ int link_count, total_link_count;
+ struct tty_struct *tty; /* NULL if no tty */
+ unsigned int locks; /* How many file locks are being held */
+/* ipc stuff */
+ struct sysv_sem sysvsem;
+/* CPU-specific state of this task */
+ struct thread_struct thread;
+/* filesystem information */
+ struct fs_struct *fs;
+/* open file information */
+ struct files_struct *files;
+/* namespace */
+ struct namespace *namespace;
+/* signal handlers */
+ spinlock_t sigmask_lock; /* Protects signal and blocked */
+ struct signal_struct *sig;
+
+ sigset_t blocked;
+ struct sigpending pending;
+
+ unsigned long sas_ss_sp;
+ size_t sas_ss_size;
+ int (*notifier)(void *priv);
+ void *notifier_data;
+ sigset_t *notifier_mask;
+
+/* Thread group tracking */
+ u32 parent_exec_id;
+ u32 self_exec_id;
+/* Protection of (de-)allocation: mm, files, fs, tty */
+ spinlock_t alloc_lock;
+
+/* journalling filesystem info */
+ void *journal_info;
+ struct dentry *proc_dentry;
+};
+
+
+#endif /* __KERNEL__ */
+
+#endif