]> git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/commit
h8300: select generic atomic64_t support
authorFengguang Wu <fengguang.wu@intel.com>
Tue, 18 Dec 2012 22:21:29 +0000 (14:21 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 18 Dec 2012 23:02:11 +0000 (15:02 -0800)
commitd95bfe464bae35daadaa46477e3ef984747abfff
tree3ab21267930ead189b8b91aa6dc2940be643bbb2
parentaf56e3f017bae54b9c3b5f7877d5eff990a2eed9
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