[openib-general] Re: RFC: revert module ref counting patches (was Re: [PATCH] ipoib_flush_paths)

[Michael S. Tsirkin]

Quoting r. Sean Hefty <mshefty at ichips.intel.com>:
> Subject: Re: RFC: revert module ref counting patches (was Re: [PATCH] ipoib_flush_paths)
> 
> Michael S. Tsirkin wrote:
> >No, its simple: A uses C -> A does flush C at unload.
> >B uses C -> B does flush C at unload.
> 
> This is C's problem.  We're forcing clients to provide the fix, which just 
> seems wrong.  The issue is that A does flush C, which must wait for B's 
> callback to complete.

Sean, as a rule, flushing never adds deadlocks unless you keep some locks while
flushing.

In our example its clear that A has to wait for its callback to run to complete.
If B and A callbacks are running on the same WQ, this means A
must wait for B's callack to complete if it gets placed in in WQ
before A callback.

So we are *not* adding an extra dependency.



-- 
MST