Re: 2.6.26-rc4: RIP __call_for_each_cic+0x20/0x50

On Tue, May 27 2008, Alexey Dobriyan wrote:
On Sat, May 10, 2008 at 02:37:19PM +0400, Alexey Dobriyan wrote:
@@ -41,8 +41,8 @@ int put_io_context(struct io_context *ioc)
rcu_read_lock();
if (ioc->aic && ioc->aic->dtor)
ioc->aic->dtor(ioc->aic);
- rcu_read_unlock();
cfq_dtor(ioc);
+ rcu_read_unlock();

kmem_cache_free(iocontext_cachep, ioc);
return 1;

This helps in sense that 3 times bulk cross-compiles finish to the end.
You'll hear me if another such oops will resurface.

Still looking good?

Yup!

And this with patch in mainline, again with PREEMPT_RCU.

Ping, this happened again with 2.6.26-rc4 and PREEMPT_RCU.

Worrisome... Paul, would you mind taking a quick look at cfq
and see if you can detect why breaks with preempt rcu? It's
clearly a use-after-free symptom, but I don't see how it can
happen.

--
Jens Axboe

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