From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264515AbTLCIvP (ORCPT ); Wed, 3 Dec 2003 03:51:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264527AbTLCIvO (ORCPT ); Wed, 3 Dec 2003 03:51:14 -0500 Received: from fmr06.intel.com ([134.134.136.7]:21202 "EHLO caduceus.jf.intel.com") by vger.kernel.org with ESMTP id S264515AbTLCItd (ORCPT ); Wed, 3 Dec 2003 03:49:33 -0500 Date: Wed, 03 Dec 2003 00:51:19 -0800 From: inaky.perez-gonzalez@intel.com To: linux-kernel@vger.kernel.org Cc: inaky.perez-gonzalez@intel.com, robustmutexes@lists.osdl.org Subject: [RFC/PATCH] FUSYN 2/10: modifications to the core Message-ID: <0312030051.TaDc4aQalbOdPa~b8ddbVaScuaBavded25502@intel.com> Content-Type: text/plain Content-Transfer-Encoding: 7bit In-Reply-To: <0312030051.abRbObyaFdidDbOaPdRdLc5b5aFbhcTd25502@intel.com> X-Mailer: patchbomb 0.0.1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org These are modifications needed to support fuqueues and fulocks. They are, in a nutshell: - Move some stuff from kernel/futex.c to futex.h to make it usable by more people. - Add neccesary fields to the task_struct. - Hookup to initialization and cleanup points for process creation and destruction. - Hookup into the signalling and time out code for wait cancellation, as well as for changing task priorities. - Add error codes for dead-owner and not-recoverable. include/asm-generic/errno-base.h | 4 +++ include/linux/futex.h | 52 +++++++++++++++++++++++++++++++++++++++ include/linux/init_task.h | 5 +++ include/linux/sched.h | 9 ++++++ kernel/Makefile | 3 +- kernel/exit.c | 3 ++ kernel/fork.c | 2 + kernel/futex.c | 39 +++-------------------------- kernel/sched.c | 52 ++++++++++++++++++++++++++++++++++++++- kernel/signal.c | 13 +++++++++ kernel/timer.c | 11 +++++++- 11 files changed, 155 insertions(+), 38 deletions(-) --- linux/include/linux/futex.h:1.1.1.1 Thu Jul 10 12:27:31 2003 +++ linux/include/linux/futex.h Sun Nov 16 07:21:32 2003 @@ -9,7 +9,11 @@ #define FUTEX_FD (2) #define FUTEX_REQUEUE (3) +#ifdef __KERNEL__ +#include + +struct timespec; asmlinkage long sys_futex(u32 __user *uaddr, int op, int val, struct timespec __user *utime, u32 __user *uaddr2); @@ -17,4 +21,52 @@ long do_futex(unsigned long uaddr, int op, int val, unsigned long timeout, unsigned long uaddr2, int val2); +/* + * Futexes are matched on equal values of this key. + * The key type depends on whether it's a shared or private mapping. + * Don't rearrange members without looking at futex_hash_key(). + * + * offset is aligned to a multiple of sizeof(u32) (== 4) by definition. + * We set bit 0 to indicate if it's an inode-based key. + */ +union futex_key { + struct { + unsigned long pgoff; + struct inode *inode; + int offset; + } shared; + struct { + unsigned long uaddr; + struct mm_struct *mm; + int offset; + } private; + struct { + unsigned long word; + void *ptr; + int offset; + } both; +}; + +static inline +u32 futex_hash_key (const union futex_key *key) +{ + u32 hash = jhash2((u32*)&key->both.word, + (sizeof(key->both.word)+sizeof(key->both.ptr))/4, + key->both.offset); + return hash; +} + +static inline +int match_futex_key (const union futex_key *key1, const union futex_key *key2) +{ + return (key1->both.word == key2->both.word + && key1->both.ptr == key2->both.ptr + && key1->both.offset == key2->both.offset); +} + +extern int get_futex_key (unsigned long uaddr, union futex_key *key); +extern void get_key_refs(union futex_key *key); +extern void drop_key_refs(union futex_key *key); + +#endif /* #ifdef __KERNEL__ */ #endif --- linux/include/linux/init_task.h:1.1.1.2 Thu Aug 28 12:38:00 2003 +++ linux/include/linux/init_task.h Sun Nov 16 07:21:32 2003 @@ -108,6 +108,11 @@ .proc_lock = SPIN_LOCK_UNLOCKED, \ .switch_lock = SPIN_LOCK_UNLOCKED, \ .journal_info = NULL, \ + .fuqueue_wait_lock = SPIN_LOCK_UNLOCKED, \ + .fuqueue_wait = NULL, \ + .fuqueue_waiter = NULL, \ + .fulock_olist = olist_INIT(&tsk.fulock_olist), \ + .fulock_olist_lock = SPIN_LOCK_UNLOCKED, \ } --- linux/include/linux/sched.h:1.1.1.9 Mon Oct 20 13:56:49 2003 +++ linux/include/linux/sched.h Sun Nov 16 07:21:32 2003 @@ -29,6 +29,7 @@ #include #include #include +#include /* olist_t */ struct exec_domain; @@ -326,7 +327,8 @@ struct sigqueue *sigq; /* signal queue entry. */ }; - +struct fuqueue; +struct fuqueue_waiter; struct io_context; /* See blkdev.h */ void exit_io_context(void); @@ -464,6 +466,11 @@ unsigned long ptrace_message; siginfo_t *last_siginfo; /* For ptrace use. */ + struct fuqueue *fuqueue_wait; /* waiting for this qeueue */ + struct fuqueue_waiter *fuqueue_waiter; /* waiting for this qeueue */ + spinlock_t fuqueue_wait_lock; /* FIXME: locking too heavy -- better sollution? */ + olist_t fulock_olist; /* Fulock ownership list */ + spinlock_t fulock_olist_lock; }; static inline pid_t process_group(struct task_struct *tsk) --- linux/kernel/Makefile:1.1.1.6 Mon Oct 20 13:55:34 2003 +++ linux/kernel/Makefile Fri Nov 21 13:26:01 2003 @@ -6,7 +6,8 @@ exit.o itimer.o time.o softirq.o resource.o \ sysctl.o capability.o ptrace.o timer.o user.o \ signal.o sys.o kmod.o workqueue.o pid.o \ - rcupdate.o intermodule.o extable.o params.o posix-timers.o + rcupdate.o intermodule.o extable.o params.o posix-timers.o \ + fuqueue.o fulock.o fulock-pp.o vlocator.o ufuqueue.o ufulock.o obj-$(CONFIG_FUTEX) += futex.o obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o --- linux/kernel/exit.c:1.1.1.7 Mon Oct 20 13:56:49 2003 +++ linux/kernel/exit.c Sun Nov 16 07:21:32 2003 @@ -704,6 +704,8 @@ local_irq_enable(); } +extern void exit_fulocks(struct task_struct *); + NORET_TYPE void do_exit(long code) { struct task_struct *tsk = current; @@ -732,6 +734,7 @@ } acct_process(code); + exit_fulocks(tsk); __exit_mm(tsk); exit_sem(tsk); --- linux/kernel/fork.c:1.1.1.9 Mon Oct 20 13:56:49 2003 +++ linux/kernel/fork.c Sun Nov 16 07:21:32 2003 @@ -40,6 +40,7 @@ extern int copy_semundo(unsigned long clone_flags, struct task_struct *tsk); extern void exit_sem(struct task_struct *tsk); +extern void init_fulock (struct task_struct *task); /* The idle threads do not count.. * Protected by write_lock_irq(&tasklist_lock) @@ -922,6 +923,7 @@ goto bad_fork_cleanup_signal; if ((retval = copy_namespace(clone_flags, p))) goto bad_fork_cleanup_mm; + init_fulock(p); retval = copy_thread(0, clone_flags, stack_start, stack_size, p, regs); if (retval) goto bad_fork_cleanup_namespace; --- linux/kernel/futex.c:1.1.1.4 Mon Oct 20 13:56:49 2003 +++ linux/kernel/futex.c Sun Nov 16 07:21:32 2003 @@ -41,31 +41,6 @@ #define FUTEX_HASHBITS 8 -/* - * Futexes are matched on equal values of this key. - * The key type depends on whether it's a shared or private mapping. - * Don't rearrange members without looking at hash_futex(). - * - * offset is aligned to a multiple of sizeof(u32) (== 4) by definition. - * We set bit 0 to indicate if it's an inode-based key. - */ -union futex_key { - struct { - unsigned long pgoff; - struct inode *inode; - int offset; - } shared; - struct { - unsigned long uaddr; - struct mm_struct *mm; - int offset; - } private; - struct { - unsigned long word; - void *ptr; - int offset; - } both; -}; /* * We use this hashed waitqueue instead of a normal wait_queue_t, so @@ -109,9 +84,7 @@ */ static struct futex_hash_bucket *hash_futex(union futex_key *key) { - u32 hash = jhash2((u32*)&key->both.word, - (sizeof(key->both.word)+sizeof(key->both.ptr))/4, - key->both.offset); + u32 hash = futex_hash_key (key); return &futex_queues[hash & ((1 << FUTEX_HASHBITS)-1)]; } @@ -120,9 +93,7 @@ */ static inline int match_futex(union futex_key *key1, union futex_key *key2) { - return (key1->both.word == key2->both.word - && key1->both.ptr == key2->both.ptr - && key1->both.offset == key2->both.offset); + return match_futex_key (key1, key2); } /* @@ -137,7 +108,7 @@ * * Should be called with ¤t->mm->mmap_sem but NOT any spinlocks. */ -static int get_futex_key(unsigned long uaddr, union futex_key *key) +int get_futex_key(unsigned long uaddr, union futex_key *key) { struct mm_struct *mm = current->mm; struct vm_area_struct *vma; @@ -232,7 +203,7 @@ * NOTE: mmap_sem MUST be held between get_futex_key() and calling this * function, if it is called at all. mmap_sem keeps key->shared.inode valid. */ -static inline void get_key_refs(union futex_key *key) +inline void get_key_refs(union futex_key *key) { if (key->both.ptr != 0) { if (key->both.offset & 1) @@ -246,7 +217,7 @@ * Drop a reference to the resource addressed by a key. * The hash bucket spinlock must not be held. */ -static inline void drop_key_refs(union futex_key *key) +inline void drop_key_refs(union futex_key *key) { if (key->both.ptr != 0) { if (key->both.offset & 1) --- linux/kernel/sched.c:1.1.1.11 Sat Nov 15 01:38:17 2003 +++ linux/kernel/sched.c Tue Nov 18 10:57:31 2003 @@ -591,7 +591,8 @@ int success = 0; long old_state; runqueue_t *rq; - + + repeat_lock_task: rq = task_rq_lock(p, &flags); old_state = p->state; @@ -1629,6 +1630,8 @@ EXPORT_SYMBOL(default_wake_function); +extern void fuqueue_wait_cancel(struct task_struct *, int); + /* * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve @@ -1637,6 +1640,9 @@ * There are circumstances in which we can try to wake a task which has already * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns * zero in this (rare) case, and we handle it by continuing to scan the queue. + * + * fuqueue_wait_cancel needs to hook up here to properly rescheduler + * priority inheritance/protected tasks. Check its doc to learn why. */ static void __wake_up_common(wait_queue_head_t *q, unsigned int mode, int nr_exclusive, int sync) { @@ -1647,6 +1653,8 @@ unsigned flags; curr = list_entry(tmp, wait_queue_t, task_list); flags = curr->flags; + if (unlikely(curr->task->fuqueue_wait != NULL)) + fuqueue_wait_cancel(curr->task, -EINTR); if (curr->func(curr, mode, sync) && (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive) @@ -1980,6 +1988,46 @@ return pid ? find_task_by_pid(pid) : current; } +/** + * Unconditionally set the effective priority of a task. + * + * Not too useful on SCHED_OTHER tasks, btw ... + * + * @p Pointer to the task in question + * @prio New priority to set + */ +#warning FIXME: need to play by POSIX rules on prio change and list repositioning because of prio inheritance + +void __set_prio (struct task_struct *p, int prio) +{ + runqueue_t *rq; + prio_array_t *array; + long flags; + int oldprio; + + rq = task_rq_lock(p, &flags); + oldprio = p->prio; + array = p->array; + if (!array) { + p->prio = prio; + goto out_unlock; + } + deactivate_task(p, task_rq(p)); + p->prio = prio; + __activate_task(p, task_rq(p)); + if (rq->curr == p) { + if (p->prio > oldprio) + resched_task(rq->curr); + } + else if (TASK_PREEMPTS_CURR (p, rq)) + resched_task(rq->curr); +out_unlock: + task_rq_unlock (rq, &flags); +} + + +extern void fuqueue_chprio (struct task_struct *); + /* * setscheduler - change the scheduling policy and/or RT priority of a thread. */ @@ -2059,6 +2107,8 @@ p->prio = MAX_USER_RT_PRIO-1 - p->rt_priority; else p->prio = p->static_prio; + if (p->fuqueue_wait != NULL) + fuqueue_chprio(p); if (array) { __activate_task(p, task_rq(p)); /* --- linux/kernel/signal.c:1.1.1.8 Mon Oct 20 13:56:49 2003 +++ linux/kernel/signal.c Tue Nov 18 10:56:36 2003 @@ -524,6 +524,8 @@ return signr; } +extern void fuqueue_wait_cancel (struct task_struct *, int); + /* * Tell a process that it has a new active signal.. * @@ -547,11 +549,19 @@ * executing another processor and just now entering stopped state. * By calling wake_up_process any time resume is set, we ensure * the process will wake up and handle its stop or death signal. + * + * fuqueue_wait_cancel needs to hook up here to properly rescheduler + * priority inheritance/protected tasks. The reason is that + * when we resched a process that has boosted another one, we + * need to kick its butt off the CPU (and lower its priority) ASAP + * so that 't' can run. */ mask = TASK_INTERRUPTIBLE; if (resume) mask |= TASK_STOPPED; if (t->state & mask) { + if (unlikely (t->fuqueue_wait != NULL)) + fuqueue_wait_cancel(t, -EINTR); wake_up_process_kick(t); return; } @@ -677,6 +687,9 @@ set_tsk_thread_flag(t, TIF_SIGPENDING); state |= TASK_INTERRUPTIBLE; } + /* FIXME: I am not that sure we need to cancel here */ + if (unlikely(t->fuqueue_wait != NULL)) + fuqueue_wait_cancel(t, -EINTR); wake_up_state(t, state); t = next_thread(t); --- linux/kernel/timer.c:1.1.1.8 Sat Nov 15 01:25:05 2003 +++ linux/kernel/timer.c Sun Nov 16 07:21:32 2003 @@ -969,9 +969,18 @@ #endif +/* + * fuqueue_wait_cancel needs to hook up here to properly rescheduler + * priority inheritance/protected tasks. Check its doc to learn why. + */ +extern void fuqueue_wait_cancel(struct task_struct *, int); + static void process_timeout(unsigned long __data) { - wake_up_process((task_t *)__data); + struct task_struct *task = (task_t *) __data; + if (unlikely(task->fuqueue_wait != NULL)) + fuqueue_wait_cancel(task, -ETIMEDOUT); + wake_up_process(task); } /** --- linux/include/asm-generic/errno-base.h:1.1.1.1 Thu Jul 10 12:27:27 2003 +++ linux/include/asm-generic/errno-base.h Sun Nov 16 07:21:32 2003 @@ -36,4 +36,8 @@ #define EDOM 33 /* Math argument out of domain of func */ #define ERANGE 34 /* Math result not representable */ + /* FIXME: ugly hack to avoid conflicts -- need to get better numbers */ +#define EOWNERDEAD 525 /* Mutex owner died */ +#define ENOTRECOVERABLE 526 /* Mutex state is not recoverable */ + #endif