From: David Miller <davem@davemloft.net>
To: fweisbec@gmail.com
Cc: sparclinux@vger.kernel.org, tj@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [BUG] percpu misaligned allocation
Date: Wed, 17 Mar 2010 23:26:48 -0700 (PDT) [thread overview]
Message-ID: <20100317.232648.59697287.davem@davemloft.net> (raw)
In-Reply-To: <20100318044930.GC5045@nowhere>
From: Frederic Weisbecker <fweisbec@gmail.com>
Date: Thu, 18 Mar 2010 05:49:33 +0100
> While using the lock events through perf in a sparc box, I can see
> the following message repeated many times:
>
> Kernel unaligned access at TPC[49357c] perf_trace_lock_acquire+0xb4/0x180
>
> It actually hangs the box as the messages are sent to a serial console.
>
> When used with perf, the trace events use a per cpu buffer allocated
> in kernel/trace/trace_event_perf.c, and the allocation appears to return
> a misaligned percpu pointer. It is aligned to 4 while it seems it
> requires to be aligned to 8.
Thanks I'll take a look at this.
RAW locks (both rwlocks and spinlocks) on sparc64 are 4-bytes
in size, maybe some piece of code is assuming that locks
are cpu word sized.
Where is perf_trace_lock_acquire() I can't find it in Linus's
tree? Does it get created by some crazy macro expansion?
next prev parent reply other threads:[~2010-03-18 6:26 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-18 4:49 Frederic Weisbecker
2010-03-18 6:26 ` David Miller [this message]
2010-03-18 6:28 ` David Miller
2010-03-18 6:36 ` Li Zefan
2010-03-18 6:39 ` Li Zefan
2010-03-18 16:56 ` Frederic Weisbecker
2010-03-18 9:30 ` Tejun Heo
2010-03-18 19:50 ` Frederic Weisbecker
2010-03-19 0:54 ` David Miller
2010-03-19 1:31 ` Frederic Weisbecker
2010-03-19 1:51 ` Tejun Heo
2010-03-19 1:57 ` David Miller
2010-03-19 2:18 ` Tejun Heo
2010-03-19 2:30 ` Frederic Weisbecker
2010-03-19 3:02 ` David Miller
2010-03-19 15:48 ` Richard Kennedy
2010-03-24 20:54 ` Maciej Rutecki
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