From d95bfe464bae35daadaa46477e3ef984747abfff Mon Sep 17 00:00:00 2001 From: Fengguang Wu <fengguang.wu@intel.com> Date: Tue, 18 Dec 2012 14:21:29 -0800 Subject: [PATCH] h8300: select generic atomic64_t support Rationales from Eric: So I just looked a little deeper and it appears architectures that do not support atomic64_t are broken. The generic atomic64 support came in 2009 to support the perf subsystem with the expectation that all architectures would implement atomic64 support. Furthermore upon inspection of the kernel atomic64_t is used in a fair number of places beyond the performance counters: block/blk-cgroup.c drivers/acpi/apei/ drivers/block/rbd.c drivers/crypto/nx/nx.h drivers/gpu/drm/radeon/radeon.h drivers/infiniband/hw/ipath/ drivers/infiniband/hw/qib/ drivers/staging/octeon/ fs/xfs/ include/linux/perf_event.h include/net/netfilter/nf_conntrack_acct.h kernel/events/ kernel/trace/ net/mac80211/key.h net/rds/ The block control group, infiniband, xfs, crypto, 802.11, netfilter. Nothing quite so fundamental as fs/namespace.c but definitely in multiplatform-code that should work, and is already broken on those architecutres. Looking at the implementation of atomic64_add_return in lib/atomic64.c the code looks as efficient as these kinds of things get. Which leads me to the conclusion that we need atomic64 support on all architectures. Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> --- arch/h8300/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig index 04bef4d25b4a..0ae445087607 100644 --- a/arch/h8300/Kconfig +++ b/arch/h8300/Kconfig @@ -3,6 +3,7 @@ config H8300 default y select HAVE_IDE select HAVE_GENERIC_HARDIRQS + select GENERIC_ATOMIC64 select HAVE_UID16 select ARCH_WANT_IPC_PARSE_VERSION select GENERIC_IRQ_SHOW -- GitLab