diff options
| -rw-r--r-- | mm/vmalloc.c | 45 |
1 files changed, 40 insertions, 5 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 0f751f2068c..ef9bdf74227 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -27,10 +27,30 @@ #include <linux/pfn.h> #include <linux/kmemleak.h> #include <linux/atomic.h> +#include <linux/llist.h> #include <asm/uaccess.h> #include <asm/tlbflush.h> #include <asm/shmparam.h> +struct vfree_deferred { + struct llist_head list; + struct work_struct wq; +}; +static DEFINE_PER_CPU(struct vfree_deferred, vfree_deferred); + +static void __vunmap(const void *, int); + +static void free_work(struct work_struct *w) +{ + struct vfree_deferred *p = container_of(w, struct vfree_deferred, wq); + struct llist_node *llnode = llist_del_all(&p->list); + while (llnode) { + void *p = llnode; + llnode = llist_next(llnode); + __vunmap(p, 1); + } +} + /*** Page table manipulation functions ***/ static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end) @@ -1184,10 +1204,14 @@ void __init vmalloc_init(void) for_each_possible_cpu(i) { struct vmap_block_queue *vbq; + struct vfree_deferred *p; vbq = &per_cpu(vmap_block_queue, i); spin_lock_init(&vbq->lock); INIT_LIST_HEAD(&vbq->free); + p = &per_cpu(vfree_deferred, i); + init_llist_head(&p->list); + INIT_WORK(&p->wq, free_work); } /* Import existing vmlist entries. */ @@ -1511,7 +1535,7 @@ static void __vunmap(const void *addr, int deallocate_pages) kfree(area); return; } - + /** * vfree - release memory allocated by vmalloc() * @addr: memory base address @@ -1520,15 +1544,25 @@ static void __vunmap(const void *addr, int deallocate_pages) * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is * NULL, no operation is performed. * - * Must not be called in interrupt context. + * Must not be called in NMI context (strictly speaking, only if we don't + * have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling + * conventions for vfree() arch-depenedent would be a really bad idea) + * */ void vfree(const void *addr) { - BUG_ON(in_interrupt()); + BUG_ON(in_nmi()); kmemleak_free(addr); - __vunmap(addr, 1); + if (!addr) + return; + if (unlikely(in_interrupt())) { + struct vfree_deferred *p = &__get_cpu_var(vfree_deferred); + llist_add((struct llist_node *)addr, &p->list); + schedule_work(&p->wq); + } else + __vunmap(addr, 1); } EXPORT_SYMBOL(vfree); @@ -1545,7 +1579,8 @@ void vunmap(const void *addr) { BUG_ON(in_interrupt()); might_sleep(); - __vunmap(addr, 0); + if (addr) + __vunmap(addr, 0); } EXPORT_SYMBOL(vunmap); |