Re: About a shortcoming of the verbs API

[Roland Dreier <rdreier-FYB4Gu1CFyUAvxtiuMwx3w@public.gmane.org>]

 >  > Actually, I tried to implement the completion callback
 >  > in a workqueue thread but ipoib_cm_handle_tx_wc() calls
 >  > netif_tx_lock() which isn't safe unless it is called
 >  > from an IRQ handler or netif_tx_lock_bh() is called first.

 > Oh, sounds like a bug in IPoIB.  I guess we could fix it by just
 > changing it to netif_tx_lock_bh()?  (Or is that not safe from an IRQ handler?)

Wait, is this still a problem with IPoIB?  As far as I can tell, the
IPoIB completion handlers don't do anything except enable the NAPI poll
routine or the transmit ring timer (ie they just do napi_schedule() or
mod_timer()), so the context that the CQ callback is called in doesn't
matter.  In particular I don't see any way ipoib_cm_handle_tx_wc() could
be reached except from the NAPI polling loop.

 - R.
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Roland Dreier <rolandd-FYB4Gu1CFyUAvxtiuMwx3w@public.gmane.org> || For corporate legal information go to:
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