Messages in this thread | | | Date | Tue, 16 Jul 2013 13:16:25 +0800 | Subject | Re: [uclinux-dist-devel] [GIT PULL] Blackfin updates for 3.11 | From | Steven Miao <> |
| |
On Tue, Jul 16, 2013 at 1:49 AM, Linus Torvalds <torvalds@linux-foundation.org> wrote: > On Mon, Jul 15, 2013 at 10:28 AM, Geert Uytterhoeven > <geert@linux-m68k.org> wrote: >> >> but the first one is non-trivial: using xchg() on atomic_t is a bit gross... > > It's also broken. There's no guarantee that an "atomic_t" is just a > value. Now, the old sparc32 stuff (which hid lock bits in atomic_t) > may be gone, but it's still the case that atomic_t may not actually > work with xchg. > > (In *practice* it works on normal architectures, so I'm not saying > that we don't have it, but it's a bug if we do). > > There are "atomic_xchg()" and "atomic_xchg64()" functions that are supported. I'll send a patch to fix it. > > Linus
| |