Re: 2.6.37-rc1 build failure

[Peter Zijlstra <peterz@infradead.org>]

On Wed, 2010-11-03 at 21:34 -0700, Randy Dunlap wrote:
> The build fails for me with the given .config file.
> It's due to selects and depends, finally comes down to HAVE_PERF_EVENTS not being
> enabled for M386 or M486.  Do you actually have a processor of that vintage?

FWIW this .config generates a _TON_ of Kconfig dep warnings..

Urgh, Kconfig hell.

config PERF_EVENTS
        bool "Kernel performance events and counters"
        default y if (PROFILING || PERF_COUNTERS)
        depends on HAVE_PERF_EVENTS
        select ANON_INODES
        select IRQ_WORK


# grep PERF_EVENTS borken-build/.config
CONFIG_PERF_EVENTS=y
CONFIG_HAVE_PERF_EVENTS_NMI=y



So we managed to get PERF_EVENTS=y even though its dependency
HAVE_PERF_EVENTS=n.


I bet that's because of:

config X86
        select HAVE_PERF_EVENTS if (!M386 && !M486)
        select PERF_EVENTS 


Ingo, should we simply do something like the below patch?

---
Subject: x86: Remove M[34]86 conditional on HAVE_PERF_EVENTS

x86 requires PERF_EVENTS because of the hardware breakpoint mess,
so don't make it conditional on M[34]86.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
 arch/x86/Kconfig |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index e832768..e330da2 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -21,7 +21,7 @@ config X86
 	select HAVE_UNSTABLE_SCHED_CLOCK
 	select HAVE_IDE
 	select HAVE_OPROFILE
-	select HAVE_PERF_EVENTS if (!M386 && !M486)
+	select HAVE_PERF_EVENTS
 	select HAVE_IRQ_WORK
 	select HAVE_IOREMAP_PROT
 	select HAVE_KPROBES