diff options
author | Andrey Ryabinin <aryabinin@virtuozzo.com> | 2016-12-12 16:44:10 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-12 18:55:08 -0800 |
commit | bf22e37a641327e34681b7b6959d9646e3886770 (patch) | |
tree | 1b672d3f1579da486197e2abd4df6990c4f61158 | |
parent | 0574ecd141df28d573d4364adec59766ddf5f38d (diff) | |
download | linux-bf22e37a641327e34681b7b6959d9646e3886770.tar.bz2 |
mm: add vfree_atomic()
We are going to use sleeping lock for freeing vmap. However some
vfree() users want to free memory from atomic (but not from interrupt)
context. For this we add vfree_atomic() - deferred variation of vfree()
which can be used in any atomic context (except NMIs).
[akpm@linux-foundation.org: tweak comment grammar]
[aryabinin@virtuozzo.com: use raw_cpu_ptr() instead of this_cpu_ptr()]
Link: http://lkml.kernel.org/r/1481553981-3856-1-git-send-email-aryabinin@virtuozzo.com
Link: http://lkml.kernel.org/r/1479474236-4139-5-git-send-email-hch@lst.de
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Jisheng Zhang <jszhang@marvell.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: John Dias <joaodias@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | include/linux/vmalloc.h | 1 | ||||
-rw-r--r-- | mm/vmalloc.c | 42 |
2 files changed, 37 insertions, 6 deletions
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index 3d9d786a943c..d68edffbf142 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -82,6 +82,7 @@ extern void *__vmalloc_node_range(unsigned long size, unsigned long align, const void *caller); extern void vfree(const void *addr); +extern void vfree_atomic(const void *addr); extern void *vmap(struct page **pages, unsigned int count, unsigned long flags, pgprot_t prot); diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 1f5501b43026..4ac776f10ad1 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1486,7 +1486,39 @@ static void __vunmap(const void *addr, int deallocate_pages) kfree(area); return; } - + +static inline void __vfree_deferred(const void *addr) +{ + /* + * Use raw_cpu_ptr() because this can be called from preemptible + * context. Preemption is absolutely fine here, because the llist_add() + * implementation is lockless, so it works even if we are adding to + * nother cpu's list. schedule_work() should be fine with this too. + */ + struct vfree_deferred *p = raw_cpu_ptr(&vfree_deferred); + + if (llist_add((struct llist_node *)addr, &p->list)) + schedule_work(&p->wq); +} + +/** + * vfree_atomic - release memory allocated by vmalloc() + * @addr: memory base address + * + * This one is just like vfree() but can be called in any atomic context + * except NMIs. + */ +void vfree_atomic(const void *addr) +{ + BUG_ON(in_nmi()); + + kmemleak_free(addr); + + if (!addr) + return; + __vfree_deferred(addr); +} + /** * vfree - release memory allocated by vmalloc() * @addr: memory base address @@ -1509,11 +1541,9 @@ void vfree(const void *addr) if (!addr) return; - if (unlikely(in_interrupt())) { - struct vfree_deferred *p = this_cpu_ptr(&vfree_deferred); - if (llist_add((struct llist_node *)addr, &p->list)) - schedule_work(&p->wq); - } else + if (unlikely(in_interrupt())) + __vfree_deferred(addr); + else __vunmap(addr, 1); } EXPORT_SYMBOL(vfree); |