Messages in this thread | | | Date | Thu, 15 Jan 2009 14:39:16 +0100 | From | Ingo Molnar <> | Subject | Re: [patch] add optimized generic percpu accessors |
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* Ingo Molnar <mingo@elte.hu> wrote:
> FYI, -tip testing found the following bug with your percpu stuff: > > There's an early exception during bootup, on 64-bit x86: > > PANIC: early exception 0e rip 10:ffffffff80276855: error ? cr2 6688 > > - gcc version 4.3.2 20081007 (Red Hat 4.3.2-6) (GCC) > - binutils-2.18.50.0.6-2.x86_64 > > config attached. You can find the disassembly of lock_release_holdtime() > below - that's where it crashed:
Gut feeling: we must have gotten a window where the PDA is not right. Note how it crashes in lock_release_holdtime() - that is CONFIG_LOCK_STAT instrumentation - very lowlevel and pervasive. Function tracing is also enabled although it should be inactive at the early stages.
So i'd take a good look at the PDA setup portion of the boot code, and see whether some spinlock acquire/release can slip in while the PDA/percpu-area is not reliable.
Ingo
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