From 476d139c218e44e045e4bc6d4cc02b010b343939 Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Sat, 25 Jun 2005 14:57:29 -0700 Subject: [PATCH] sched: consolidate sbe sbf Consolidate balance-on-exec with balance-on-fork. This is made easy by the sched-domains RCU patches. As well as the general goodness of code reduction, this allows the runqueues to be unlocked during balance-on-fork. schedstats is a problem. Maybe just have balance-on-event instead of distinguishing fork and exec? Signed-off-by: Nick Piggin Acked-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/fork.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) (limited to 'kernel/fork.c') diff --git a/kernel/fork.c b/kernel/fork.c index a28d11e10877..2c7806873bfd 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1003,9 +1003,6 @@ static task_t *copy_process(unsigned long clone_flags, p->pdeath_signal = 0; p->exit_state = 0; - /* Perform scheduler related setup */ - sched_fork(p); - /* * Ok, make it visible to the rest of the system. * We dont wake it up yet. @@ -1014,18 +1011,24 @@ static task_t *copy_process(unsigned long clone_flags, INIT_LIST_HEAD(&p->ptrace_children); INIT_LIST_HEAD(&p->ptrace_list); + /* Perform scheduler related setup. Assign this task to a CPU. */ + sched_fork(p, clone_flags); + /* Need tasklist lock for parent etc handling! */ write_lock_irq(&tasklist_lock); /* - * The task hasn't been attached yet, so cpus_allowed mask cannot - * have changed. The cpus_allowed mask of the parent may have - * changed after it was copied first time, and it may then move to - * another CPU - so we re-copy it here and set the child's CPU to - * the parent's CPU. This avoids alot of nasty races. + * The task hasn't been attached yet, so its cpus_allowed mask will + * not be changed, nor will its assigned CPU. + * + * The cpus_allowed mask of the parent may have changed after it was + * copied first time - so re-copy it here, then check the child's CPU + * to ensure it is on a valid CPU (and if not, just force it back to + * parent's CPU). This avoids alot of nasty races. */ p->cpus_allowed = current->cpus_allowed; - set_task_cpu(p, smp_processor_id()); + if (unlikely(!cpu_isset(task_cpu(p), p->cpus_allowed))) + set_task_cpu(p, smp_processor_id()); /* * Check for pending SIGKILL! The new thread should not be allowed -- cgit v1.2.2 From 22e2c507c301c3dbbcf91b4948b88f78842ee6c9 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 27 Jun 2005 10:55:12 +0200 Subject: [PATCH] Update cfq io scheduler to time sliced design This updates the CFQ io scheduler to the new time sliced design (cfq v3). It provides full process fairness, while giving excellent aggregate system throughput even for many competing processes. It supports io priorities, either inherited from the cpu nice value or set directly with the ioprio_get/set syscalls. The latter closely mimic set/getpriority. This import is based on my latest from -mm. Signed-off-by: Jens Axboe Signed-off-by: Linus Torvalds --- kernel/fork.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'kernel/fork.c') diff --git a/kernel/fork.c b/kernel/fork.c index 2c7806873bfd..cdef6cea8900 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1090,6 +1090,11 @@ static task_t *copy_process(unsigned long clone_flags, spin_unlock(¤t->sighand->siglock); } + /* + * inherit ioprio + */ + p->ioprio = current->ioprio; + SET_LINKS(p); if (unlikely(p->ptrace & PT_PTRACED)) __ptrace_link(p, current->parent); -- cgit v1.2.2 From 3b6bfcdb116f2cc2cab921fcac6d39d4022952d2 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Tue, 12 Jul 2005 13:58:09 -0700 Subject: [PATCH] lower VM_DONTCOPY total_vm dup_mmap of a VM_DONTCOPY vma forgot to lower the child's total_vm. (But no way does this account for the recent report of total_vm seen too low.) Signed-off-by: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/fork.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'kernel/fork.c') diff --git a/kernel/fork.c b/kernel/fork.c index cdef6cea8900..b65187f0c74e 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -208,8 +208,10 @@ static inline int dup_mmap(struct mm_struct * mm, struct mm_struct * oldmm) struct file *file; if (mpnt->vm_flags & VM_DONTCOPY) { + long pages = vma_pages(mpnt); + mm->total_vm -= pages; __vm_stat_account(mm, mpnt->vm_flags, mpnt->vm_file, - -vma_pages(mpnt)); + -pages); continue; } charge = 0; -- cgit v1.2.2