From 6ecf6d7228fbb29cfe6a335f5afc20f75493a791 Mon Sep 17 00:00:00 2001 From: Richard Yao Date: Thu, 17 Apr 2014 10:59:00 -0400 Subject: [PATCH] Revert "Add PF_NOFS debugging flag" This reverts commit eb0f407a2b9089113ef6f2402ebd887511315b43 in preperation for updating the kmem/vmem infrastructure to use the PF_FSTRANS flag. Signed-off-by: Brian Behlendorf --- include/sys/kmem.h | 49 ---------------------------------------------- 1 file changed, 49 deletions(-) diff --git a/include/sys/kmem.h b/include/sys/kmem.h index 936e49d..2bfb4d0 100644 --- a/include/sys/kmem.h +++ b/include/sys/kmem.h @@ -56,47 +56,6 @@ # define __GFP_ZERO 0x8000 #endif -/* - * PF_NOFS is a per-process debug flag which is set in current->flags to - * detect when a process is performing an unsafe allocation. All tasks - * with PF_NOFS set must strictly use KM_PUSHPAGE for allocations because - * if they enter direct reclaim and initiate I/O the may deadlock. - * - * When debugging is disabled, any incorrect usage will be detected and - * a call stack with warning will be printed to the console. The flags - * will then be automatically corrected to allow for safe execution. If - * debugging is enabled this will be treated as a fatal condition. - * - * To avoid any risk of conflicting with the existing PF_ flags. The - * PF_NOFS bit shadows the rarely used PF_MUTEX_TESTER bit. Only when - * CONFIG_RT_MUTEX_TESTER is not set, and we know this bit is unused, - * will the PF_NOFS bit be valid. Happily, most existing distributions - * ship a kernel with CONFIG_RT_MUTEX_TESTER disabled. - */ -#if !defined(CONFIG_RT_MUTEX_TESTER) && defined(PF_MUTEX_TESTER) -#define PF_NOFS PF_MUTEX_TESTER - -static inline void -sanitize_flags(struct task_struct *p, gfp_t *flags) -{ - if (unlikely((p->flags & PF_NOFS) && (*flags & (__GFP_IO|__GFP_FS)))) { -#ifdef NDEBUG - printk(KERN_WARNING "Fixing allocation for task %s (%d) " - "which used GFP flags 0x%x with PF_NOFS set\n", - p->comm, p->pid, *flags); - spl_dumpstack(); - *flags &= ~(__GFP_IO|__GFP_FS); -#else - PANIC("FATAL allocation for task %s (%d) which used GFP " - "flags 0x%x with PF_NOFS set\n", p->comm, p->pid, *flags); -#endif /* NDEBUG */ - } -} -#else -#define PF_NOFS 0x00000000 -#define sanitize_flags(p, fl) ((void)0) -#endif /* !defined(CONFIG_RT_MUTEX_TESTER) && defined(PF_MUTEX_TESTER) */ - /* * __GFP_NOFAIL looks like it will be removed from the kernel perhaps as * early as 2.6.32. To avoid this issue when it occurs in upstream kernels @@ -109,8 +68,6 @@ kmalloc_nofail(size_t size, gfp_t flags) { void *ptr; - sanitize_flags(current, &flags); - do { ptr = kmalloc(size, flags); } while (ptr == NULL && (flags & __GFP_WAIT)); @@ -123,8 +80,6 @@ kzalloc_nofail(size_t size, gfp_t flags) { void *ptr; - sanitize_flags(current, &flags); - do { ptr = kzalloc(size, flags); } while (ptr == NULL && (flags & __GFP_WAIT)); @@ -137,8 +92,6 @@ kmalloc_node_nofail(size_t size, gfp_t flags, int node) { void *ptr; - sanitize_flags(current, &flags); - do { ptr = kmalloc_node(size, flags, node); } while (ptr == NULL && (flags & __GFP_WAIT)); @@ -151,8 +104,6 @@ vmalloc_nofail(size_t size, gfp_t flags) { void *ptr; - sanitize_flags(current, &flags); - /* * Retry failed __vmalloc() allocations once every second. The * rational for the delay is that the likely failure modes are: -- 2.40.0