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    SubjectRe: [PATCH] memory-model: fix cheat sheet typo
    On Mon, Apr 09, 2018 at 11:42:58AM -0700, Paul E. McKenney wrote:
    > On Mon, Apr 09, 2018 at 06:50:15PM +0200, Paolo Bonzini wrote:
    > > "RWM" should be "RMW", and that's more or less the extent to which I
    > > can claim to change the document. :) In particular, "Self" is not
    > > documented and the difference between "Self" and "SV" is not clear
    > > to me.
    > >
    > > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
    >
    > Applied, though without the questions. ;-)
    >
    > "Self" is for things like smp_load_acquire() and smp_store_release()
    > that order themselves against later and earlier accesses, respectively.
    > This ordering applies to later/earlier access to all variables, not
    > just the one that smp_load_acquire()/smp_store_release() accessed.
    > In contrast, things like smp_mb() order only other accesses, not
    > themselves. Or at least it is impossible to proves whether or not they
    > order themselves because they are not separately visible to other CPUs.
    >
    > "SV" is "same variable", which applies to pretty much anything that
    > accesses a variable, but not to things like smp_mb() which do not.
    >
    > Does that help?

    On the perhaps naive assumption that silence means assent, how about
    the following patch?

    Thanx, Paul

    ------------------------------------------------------------------------

    commit 818e46e8db6cacb099b8640b7f2945a3151c00ab
    Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
    Date: Tue Apr 10 13:24:19 2018 -0700

    tools/memory-order: Improve key for SELF and SV

    The key for "SELF" was missing completely and the key for "SV" was
    a bit obtuse. This commit therefore adds a key for "SELF" and improves
    the one for "SV".

    Reported-by: Paolo Bonzini <pbonzini@redhat.com>
    Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

    diff --git a/tools/memory-model/Documentation/cheatsheet.txt b/tools/memory-model/Documentation/cheatsheet.txt
    index c0eafdaddfa4..d502993ac7d2 100644
    --- a/tools/memory-model/Documentation/cheatsheet.txt
    +++ b/tools/memory-model/Documentation/cheatsheet.txt
    @@ -26,4 +26,5 @@ Key: C: Ordering is cumulative
    DR: Dependent read (address dependency)
    DW: Dependent write (address, data, or control dependency)
    RMW: Atomic read-modify-write operation
    - SV Same-variable access
    + SELF: Orders self, as opposed to accesses both before and after
    + SV: Orders later accesses to the same variable
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