diff options
| author | Richard Henderson <rth@twiddle.net> | 2013-07-12 16:15:56 -0700 |
|---|---|---|
| committer | Matt Turner <mattst88@gmail.com> | 2013-11-16 16:33:13 -0800 |
| commit | fddd87d6e135924b92499917bace103e46c22d00 (patch) | |
| tree | 23bbe6a01a32c0ea88f7c2180dbd1f461d822c76 /arch/alpha/Kconfig | |
| parent | 994dcf7055df88623d25f3593b931a018a76b502 (diff) | |
alpha: Allow HZ to be configured
With the 1024Hz default, we spend 50% of QEMU emulation
processing timer interrupts.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Diffstat (limited to 'arch/alpha/Kconfig')
| -rw-r--r-- | arch/alpha/Kconfig | 36 |
1 files changed, 34 insertions, 2 deletions
diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig index 51cc8c353164..a67b971c830a 100644 --- a/arch/alpha/Kconfig +++ b/arch/alpha/Kconfig @@ -627,9 +627,41 @@ config VERBOSE_MCHECK_ON Take the default (1) unless you want more control or more info. +choice + prompt "Timer interrupt frequency (HZ)?" + default HZ_128 if ALPHA_QEMU + default HZ_1200 if ALPHA_RAWHIDE + default HZ_1024 + ---help--- + The frequency at which timer interrupts occur. A high frequency + minimizes latency, whereas a low frequency minimizes overhead of + process accounting. The later effect is especially significant + when being run under QEMU. + + Note that some Alpha hardware cannot change the interrupt frequency + of the timer. If unsure, say 1024 (or 1200 for Rawhide). + + config HZ_32 + bool "32 Hz" + config HZ_64 + bool "64 Hz" + config HZ_128 + bool "128 Hz" + config HZ_256 + bool "256 Hz" + config HZ_1024 + bool "1024 Hz" + config HZ_1200 + bool "1200 Hz" +endchoice + config HZ - int - default 1200 if ALPHA_RAWHIDE + int + default 32 if HZ_32 + default 64 if HZ_64 + default 128 if HZ_128 + default 256 if HZ_256 + default 1200 if HZ_1200 default 1024 source "drivers/pci/Kconfig" |