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authorRichard Weinberger <richard@nod.at>2011-04-14 15:22:18 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-04-14 16:06:56 -0700
commit084189a88754d40e1bb9bfbc278e70c33e571685 (patch)
tree5cf285a6c648b896ee8590931d74f921c5c7f8dd /arch/um
parent6d56dad3ae070511e59792a62f27b2394cc936bc (diff)
um: disable CONFIG_CMPXCHG_LOCAL
Commit 8a5ec0ba "Lockless (and preemptless) fastpaths for slub" makes use of this_cpu_cmpxchg_double() which needs this_cpu_cmpxchg16b_emu() on x86_64. Implementing cmpxchg16b emulation for UML would introduce too much complexity. So just disable it. Signed-off-by: Richard Weinberger <richard@nod.at> Reported-by: Sergei Trofimovich <slyich@gmail.com> Acked-by: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/um')
-rw-r--r--arch/um/Kconfig.x864
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/um/Kconfig.x86 b/arch/um/Kconfig.x86
index 02fb017fed4..a9da516a527 100644
--- a/arch/um/Kconfig.x86
+++ b/arch/um/Kconfig.x86
@@ -4,6 +4,10 @@ menu "UML-specific options"
menu "Host processor type and features"
+config CMPXCHG_LOCAL
+ bool
+ default n
+
source "arch/x86/Kconfig.cpu"
endmenu