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| author | Peter Maydell <peter.maydell@linaro.org> | 2014-03-10 14:56:30 +0000 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2014-03-10 14:56:30 +0000 |
| commit | 72c1d3af6e9c2745edfeaa71918a68bcee4b79db (patch) | |
| tree | d7d01966c8d75f5427fc2a9bce5994b17fe79253 /target-arm/helper.h | |
| parent | 2b194951c592ad670ddf3bc5764216408ade46f8 (diff) | |
| download | qemu-72c1d3af6e9c2745edfeaa71918a68bcee4b79db.tar.gz | |
target-arm: Implement WFE as a yield operation
Implement WFE to yield our timeslice to the next CPU.
This avoids slowdowns in multicore configurations caused
by one core busy-waiting on a spinlock which can't possibly
be unlocked until the other core has an opportunity to run.
This speeds up my test case A15 dual-core boot by a factor
of three (though it is still four or five times slower than
a single-core boot).
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1393339545-22111-1-git-send-email-peter.maydell@linaro.org
Reviewed-by: Richard Henderson <rth@twiddle.net>
Tested-by: Rob Herring <rob.herring@linaro.org>
Diffstat (limited to 'target-arm/helper.h')
| -rw-r--r-- | target-arm/helper.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/target-arm/helper.h b/target-arm/helper.h index 276f3a9149..8923f8ae71 100644 --- a/target-arm/helper.h +++ b/target-arm/helper.h @@ -50,6 +50,7 @@ DEF_HELPER_FLAGS_3(sel_flags, TCG_CALL_NO_RWG_SE, i32, i32, i32, i32) DEF_HELPER_2(exception, void, env, i32) DEF_HELPER_1(wfi, void, env) +DEF_HELPER_1(wfe, void, env) DEF_HELPER_3(cpsr_write, void, env, i32, i32) DEF_HELPER_1(cpsr_read, i32, env) |