Messages in this thread | | | Date | Mon, 25 Sep 2006 17:16:06 -0700 | From | Jeremy Fitzhardinge <> | Subject | Re: [PATCH] Linux Kernel Markers 0.13 for 2.6.17 |
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Mathieu Desnoyers wrote: > Just as a precision : > > The following sequence (please refer to the code below for local symbols > 1 and 2) : > > 1: > preempt_disable() > call (*__mark_call_##name)(format, ## args); > preempt_enable_no_resched() > 2: > > is insured because : > > 1 is part of an inline assembly with rw dependency on __marker_sequencer > the call is surrounded by memory barriers. > 2 is part of an inline assembly with rw dependency on __marker_sequencer >
What do you mean the call is surrounded by memory barriers? Do you mean a call has an implicit barrier, or something else?
Either way, this doesn't prevent some otherwise unrelated non-memory-using code from being scheduled in there, which would not be executed. The gcc manual really strongly discourages jumping between inline asms, because they have basically unpredictable results.
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