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| author | Richard Weinberger <richard@nod.at> | 2011-04-14 15:22:18 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-04-14 16:06:56 -0700 |
| commit | 084189a88754d40e1bb9bfbc278e70c33e571685 (patch) | |
| tree | 5cf285a6c648b896ee8590931d74f921c5c7f8dd /arch/um | |
| parent | 6d56dad3ae070511e59792a62f27b2394cc936bc (diff) | |
| download | lwn-084189a88754d40e1bb9bfbc278e70c33e571685.tar.gz lwn-084189a88754d40e1bb9bfbc278e70c33e571685.zip | |
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.x86 | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/um/Kconfig.x86 b/arch/um/Kconfig.x86 index 02fb017fed47..a9da516a5274 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 |