Re: [patch] revert: [NET]: Fix races in net_rx_action vs netpoll

[Olaf Kirch]

On Thursday 19 July 2007 12:01, Ingo Molnar wrote:
>  Calling initcall 0xc0603f55: netpoll_init+0x0/0x39()
>  initcall 0xc0603f55: netpoll_init+0x0/0x39() returned 0.
>  initcall 0xc0603f55 ran for 0 msecs: netpoll_init+0x0/0x39()
>  Calling initcall 0xc0604257: netlink_proto_init+0x0/0x12a()
>  NET: Registered protocol family 16
> 
> and no output ever since - and the box has been up for a few minutes.

Okay, I need to ask a stupid question - did you verify that it's not
spinning on a spinlock?

Specifically, I'm wondering whether the net_rx_action softirq may
be scheduled while we're in poll_napi holding the poll_lock.
net_rx_action would try to take the poll_lock as well, and we'd
be hung for good. The patch with local_bh_disable/enable was
supposed to test that idea (this is the "trickle" patch)

Olaf
-- 
Olaf Kirch  |  --- o --- Nous sommes du soleil we love when we play
okir@xxxxxx |    / | \   sol.dhoop.naytheet.ah kin.ir.samse.qurax
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