On 6/16/21 12:30 AM, Peter Zijlstra wrote: > On Wed, Jun 16, 2021 at 02:00:37PM +1000, Nicholas Piggin wrote: >> Excerpts from Andy Lutomirski's message of June 16, 2021 1:21 pm: >>> We had a nice comment at the top of membarrier.c explaining why membarrier >>> worked in a handful of scenarios, but that consisted more of a list of >>> things not to forget than an actual description of the algorithm and why it >>> should be expected to work. >>> >>> Add a comment explaining my understanding of the algorithm. This exposes a >>> couple of implementation issues that I will hopefully fix up in subsequent >>> patches. >>> >>> Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> >>> Cc: Nicholas Piggin <npiggin@xxxxxxxxx> >>> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> >>> Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx> >>> --- >>> kernel/sched/membarrier.c | 55 +++++++++++++++++++++++++++++++++++++++ >>> 1 file changed, 55 insertions(+) >>> >>> diff --git a/kernel/sched/membarrier.c b/kernel/sched/membarrier.c >>> index b5add64d9698..3173b063d358 100644 >>> --- a/kernel/sched/membarrier.c >>> +++ b/kernel/sched/membarrier.c >>> @@ -7,6 +7,61 @@ >>> #include "sched.h" >>> >> >> Precisely describing the orderings is great, not a fan of the style of the >> comment though. > > I'm with Nick on that; I can't read it :/ It only makes things more > confusing. If you want precision, English (or any natural language) is > your enemy. > > To describe ordering use the diagrams and/or litmus tests. > I made some changes. Maybe it's better now.
