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| author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2006-09-28 16:55:39 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2006-09-28 16:55:39 +0200 |
| commit | d9f7a745d55527d0d41684b22506a86c4381f7f1 (patch) | |
| tree | ea8870ef06c3723ad59b78aac97bfe8152894c72 /arch/s390/Kconfig | |
| parent | 1fce518e8e7de62597c823d6d795cafc694e7910 (diff) | |
| download | lwn-d9f7a745d55527d0d41684b22506a86c4381f7f1.tar.gz lwn-d9f7a745d55527d0d41684b22506a86c4381f7f1.zip | |
[S390] __div64_32 for 31 bit.
The clocksource infrastructure introduced with commit
ad596171ed635c51a9eef829187af100cbf8dcf7 broke 31 bit s390.
The reason is that the do_div() primitive for 31 bit always
had a restriction: it could only divide an unsigned 64 bit
integer by an unsigned 31 bit integer. The clocksource code
now uses do_div() with a base value that has the most
significant bit set. The result is that clock->cycle_interval
has a funny value which causes the linux time to jump around
like mad.
The solution is "obvious": implement a proper __div64_32
function for 31 bit s390.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/Kconfig')
| -rw-r--r-- | arch/s390/Kconfig | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index b216ca659cdf..b6b42f9f0d52 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -51,6 +51,10 @@ config 64BIT Select this option if you have a 64 bit IBM zSeries machine and want to use the 64 bit addressing mode. +config 32BIT + bool + default y if !64BIT + config SMP bool "Symmetric multi-processing support" ---help--- |