From 215e262f2aeba378aa192da07c30770f9925a4bf Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Fri, 31 May 2013 15:26:45 -0700 Subject: percpu: implement generic percpu refcounting This implements a refcount with similar semantics to atomic_get()/atomic_dec_and_test() - but percpu. It also implements two stage shutdown, as we need it to tear down the percpu counts. Before dropping the initial refcount, you must call percpu_ref_kill(); this puts the refcount in "shutting down mode" and switches back to a single atomic refcount with the appropriate barriers (synchronize_rcu()). It's also legal to call percpu_ref_kill() multiple times - it only returns true once, so callers don't have to reimplement shutdown synchronization. [akpm@linux-foundation.org: fix build] [akpm@linux-foundation.org: coding-style tweak] Signed-off-by: Kent Overstreet Cc: Zach Brown Cc: Felipe Balbi Cc: Greg Kroah-Hartman Cc: Mark Fasheh Cc: Joel Becker Cc: Rusty Russell Cc: Jens Axboe Cc: Asai Thambi S P Cc: Selvan Mani Cc: Sam Bradshaw Cc: Jeff Moyer Cc: Al Viro Cc: Benjamin LaHaise Cc: Tejun Heo Cc: Oleg Nesterov Cc: Christoph Lameter Cc: Ingo Molnar Reviewed-by: "Theodore Ts'o" Signed-off-by: Tejun Heo --- lib/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib/Makefile') diff --git a/lib/Makefile b/lib/Makefile index c55a037a354e..386db4bbc265 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -13,7 +13,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \ sha1.o md5.o irq_regs.o reciprocal_div.o argv_split.o \ proportions.o flex_proportions.o prio_heap.o ratelimit.o show_mem.o \ is_single_threaded.o plist.o decompress.o kobject_uevent.o \ - earlycpio.o + earlycpio.o percpu-refcount.o obj-$(CONFIG_ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS) += usercopy.o lib-$(CONFIG_MMU) += ioremap.o -- cgit v1.2.3-59-g8ed1b