Commit 40f15ad8 authored by Ingo Molnar's avatar Ingo Molnar

x86: disable X86_PTRACE_BTS

there's a new ptrace arch level feature in .28:

  config X86_PTRACE_BTS
  bool "Branch Trace Store"

it has broken fork() handling: the old DS area gets copied over into
a new task without clearing it.

Fixes exist but they came too late:

  c5dee617: x86, bts: memory accounting
  bf53de90: x86, bts: add fork and exit handling

and are queued up for v2.6.29. This shows that the facility is still not
tested well enough to release into a stable kernel - disable it for now and
reactivate in .29. In .29 the hardware-branch-tracer will use the DS/BTS
facilities too - hopefully resulting in better code.
Signed-off-by: default avatarIngo Molnar <>
parent 280a9ca5
......@@ -520,6 +520,7 @@ config X86_PTRACE_BTS
bool "Branch Trace Store"
default y
depends on X86_DEBUGCTLMSR
depends on BROKEN
This adds a ptrace interface to the hardware's branch trace store.
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