From 2af00decb8b198abbcb8c3baf4adfab31e86e05e Mon Sep 17 00:00:00 2001 From: Konstantin Belousov Date: Tue, 8 Sep 2009 15:31:23 +0000 Subject: MFC r196730: Remove the altkstacks, instead instantiate threads with kernel stack allocated with the right size from the start. For the thread that has kernel stack cached, verify that requested stack size is equial to the actual, and reallocate the stack if sizes differ. Introduce separate kernel stack cache that keeps some limited amount of preallocated kernel stacks to lower the latency of thread allocation. Not a merge: instead of removing td_altkstack* members of struct thread, replace them with placeholders to keep struct thread layout on the stable branch. Also, record r196640, r196644 and r196648 as merged. Approved by: re (kensmith) --- sys/kern/kern_thread.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) (limited to 'sys/kern/kern_thread.c') diff --git a/sys/kern/kern_thread.c b/sys/kern/kern_thread.c index d47bd8cef8b6..4f3b32cdd0ae 100644 --- a/sys/kern/kern_thread.c +++ b/sys/kern/kern_thread.c @@ -283,7 +283,7 @@ thread_reap(void) * Allocate a thread. */ struct thread * -thread_alloc(void) +thread_alloc(int pages) { struct thread *td; @@ -291,7 +291,7 @@ thread_alloc(void) td = (struct thread *)uma_zalloc(thread_zone, M_WAITOK); KASSERT(td->td_kstack == 0, ("thread_alloc got thread with kstack")); - if (!vm_thread_new(td, 0)) { + if (!vm_thread_new(td, pages)) { uma_zfree(thread_zone, td); return (NULL); } @@ -299,6 +299,17 @@ thread_alloc(void) return (td); } +int +thread_alloc_stack(struct thread *td, int pages) +{ + + KASSERT(td->td_kstack == 0, + ("thread_alloc_stack called on a thread with kstack")); + if (!vm_thread_new(td, pages)) + return (0); + cpu_thread_alloc(td); + return (1); +} /* * Deallocate a thread. @@ -312,8 +323,6 @@ thread_free(struct thread *td) cpuset_rel(td->td_cpuset); td->td_cpuset = NULL; cpu_thread_free(td); - if (td->td_altkstack != 0) - vm_thread_dispose_altkstack(td); if (td->td_kstack != 0) vm_thread_dispose(td); uma_zfree(thread_zone, td); -- cgit v1.2.3