[NET]: Disable NET_SCH_CLK_CPU for SMP x86 hosts (34cb711b) · Commits · 戴 / test

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>

net/sched/Kconfig

+3 −1

Original line number	Diff line number	Diff line
		@@ -72,9 +72,11 @@ config NET_SCH_CLK_GETTIMEOFDAY
		Choose this if you need a high resolution clock source but can't use
		the CPU's cycle counter.

		# don't allow on SMP x86 because they can have unsynchronized TSCs.
		# gettimeofday is a good alternative
		config NET_SCH_CLK_CPU
		bool "CPU cycle counter"
		depends on X86_TSC \|\| X86_64 \|\| ALPHA \|\| SPARC64 \|\| PPC64 \|\| IA64
		depends on ((X86_TSC \|\| X86_64) && !SMP) \|\| ALPHA \|\| SPARC64 \|\| PPC64 \|\| IA64
		help
		Say Y here if you want to use the CPU's cycle counter as clock source.
		This is a cheap and high resolution clock source, but on some

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