diff options
author | Andi Kleen <ak@suse.de> | 2005-10-13 17:41:44 -0400 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2005-10-13 17:41:44 -0400 |
commit | 34cb711ba922f53cca45443b8c3c1078873cf599 (patch) | |
tree | 2b120d59460047caff9546d68f445626947d47fc /net/sched | |
parent | c8923c6b852d3a97c1faad0566e38fca330375a7 (diff) |
[NET]: Disable NET_SCH_CLK_CPU for SMP x86 hosts
Opterons with frequency scaling have fully unsynchronized TSCs
running at different frequencies, so using TSCs there is not a good idea.
Also some other x86 boxes have this problem. gettimeofday should be good
enough, so just disable it.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched')
-rw-r--r-- | net/sched/Kconfig | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/net/sched/Kconfig b/net/sched/Kconfig index 45d3bc0812c8..81510da31792 100644 --- a/net/sched/Kconfig +++ b/net/sched/Kconfig | |||
@@ -72,9 +72,11 @@ config NET_SCH_CLK_GETTIMEOFDAY | |||
72 | Choose this if you need a high resolution clock source but can't use | 72 | Choose this if you need a high resolution clock source but can't use |
73 | the CPU's cycle counter. | 73 | the CPU's cycle counter. |
74 | 74 | ||
75 | # don't allow on SMP x86 because they can have unsynchronized TSCs. | ||
76 | # gettimeofday is a good alternative | ||
75 | config NET_SCH_CLK_CPU | 77 | config NET_SCH_CLK_CPU |
76 | bool "CPU cycle counter" | 78 | bool "CPU cycle counter" |
77 | depends on X86_TSC || X86_64 || ALPHA || SPARC64 || PPC64 || IA64 | 79 | depends on ((X86_TSC || X86_64) && !SMP) || ALPHA || SPARC64 || PPC64 || IA64 |
78 | help | 80 | help |
79 | Say Y here if you want to use the CPU's cycle counter as clock source. | 81 | Say Y here if you want to use the CPU's cycle counter as clock source. |
80 | This is a cheap and high resolution clock source, but on some | 82 | This is a cheap and high resolution clock source, but on some |