Messages in this thread | | | Date | Sun, 19 Apr 2020 21:29:57 +0300 | From | Petko Manolov <> | Subject | Re: [RFC] WRITE_ONCE_INC() and friends |
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On 20-04-19 18:02:50, David Laight wrote: > From: Petko Manolov > > Sent: 19 April 2020 10:45 > > Recently I started reading up on KCSAN and at some point I ran into stuff like: > > > > WRITE_ONCE(ssp->srcu_lock_nesting[idx], ssp->srcu_lock_nesting[idx] + 1); > > WRITE_ONCE(p->mm->numa_scan_seq, READ_ONCE(p->mm->numa_scan_seq) + 1); > > If all the accesses use READ/WRITE_ONCE() why not just mark the structure > field 'volatile'?
This is a bit heavy. I guess you've read this one:
https://lwn.net/Articles/233479/
And no, i am not sure all accesses are through READ/WRITE_ONCE(). If, for example, all others are from withing spin_lock/unlock pairs then we _may_ not need READ/WRITE_ONCE().
I merely proposed the _INC() variant for better readability.
Petko
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