diff options
| author | Richard Braun <rbraun@sceen.net> | 2016-03-09 23:06:25 +0100 |
|---|---|---|
| committer | Richard Braun <rbraun@sceen.net> | 2016-03-09 23:10:32 +0100 |
| commit | 844fb104f5c0c50b94cbf6ab8fb2e97caa4bc7b3 (patch) | |
| tree | c1fd8b6bb58570c24e4495edfd062f8a95f53500 | |
| parent | 2ac2a45ace8fd00b3ac42e3be9dbfbaad95ac819 (diff) | |
Fix stack allocation on Xen
Stack allocation on Xen can fail because of fragmentation. This change
makes stack allocation use the slab allocator.
* kern/thread.c (thread_stack_cache): New global variable.
(stack_alloc): Use kmem_cache_alloc instead of vm_page_grab_contig.
(stack_collect): Use kmem_cache_free instead of vm_page_free_contig.
(kmem_cache_init): Initialize thread_stack_cache.
| -rw-r--r-- | kern/thread.c | 33 |
1 files changed, 12 insertions, 21 deletions
diff --git a/kern/thread.c b/kern/thread.c index a2ec3d31..ce44ed14 100644 --- a/kern/thread.c +++ b/kern/thread.c @@ -70,6 +70,7 @@ thread_t active_threads[NCPUS]; vm_offset_t active_stacks[NCPUS]; struct kmem_cache thread_cache; +struct kmem_cache thread_stack_cache; queue_head_t reaper_queue; decl_simple_lock_data(, reaper_lock) @@ -195,23 +196,8 @@ kern_return_t stack_alloc( (void) splx(s); if (stack == 0) { - struct vm_page *page; - - for (;;) { - /* - * Kernel stacks should be naturally aligned, - * so that it is easy to find the starting/ending - * addresses of a stack given an address in the middle. - */ - page = vm_page_grab_contig(KERNEL_STACK_SIZE, - VM_PAGE_SEL_DIRECTMAP); - if (page != NULL) - break; - - VM_PAGE_WAIT(NULL); - } - - stack = phystokv(vm_page_to_pa(page)); + stack = kmem_cache_alloc(&thread_stack_cache); + assert(stack != 0); #if MACH_DEBUG stack_init(stack); #endif /* MACH_DEBUG */ @@ -257,7 +243,6 @@ void stack_free( void stack_collect(void) { - struct vm_page *page; vm_offset_t stack; spl_t s; @@ -273,9 +258,7 @@ void stack_collect(void) #if MACH_DEBUG stack_finalize(stack); #endif /* MACH_DEBUG */ - page = vm_page_lookup_pa(kvtophys(stack)); - assert(page != NULL); - vm_page_free_contig(page, KERNEL_STACK_SIZE); + kmem_cache_free(&thread_stack_cache, stack); s = splsched(); stack_lock(); @@ -309,6 +292,14 @@ void thread_init(void) { kmem_cache_init(&thread_cache, "thread", sizeof(struct thread), 0, NULL, 0); + /* + * Kernel stacks should be naturally aligned, + * so that it is easy to find the starting/ending + * addresses of a stack given an address in the middle. + */ + kmem_cache_init(&thread_stack_cache, "thread_stack", + KERNEL_STACK_SIZE, KERNEL_STACK_SIZE, + NULL, 0); /* * Fill in a template thread for fast initialization. |