From: David Howells <dhowe...@redhat.com> There has been some confusion about the purpose of memory-barriers.txt, so this commit adds a statement of purpose.
Signed-off-by: David Howells <dhowe...@redhat.com> Signed-off-by: Paul E. McKenney <paul...@linux.vnet.ibm.com> --- Documentation/memory-barriers.txt | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt index fb2dd35a823a..8b11e54238bf 100644 --- a/Documentation/memory-barriers.txt +++ b/Documentation/memory-barriers.txt @@ -19,6 +19,22 @@ in case of any doubt (and there are many) please ask. To repeat, this document is not a specification of what Linux expects from hardware. +The purpose of this document is twofold: + + (1) to specify the minimum functionality that one can rely on for any + particular barrier, and + + (2) to provide a guide as to how to use the barriers that are available. + +Note that an architecture can provide more than the minimum requirement +for any particular barrier, but if the architecure provides less than +that, that architecture is incorrect. + +Note also that it is possible that a barrier may be a no-op for an +architecture because the way that arch works renders an explicit barrier +unnecessary in that case. + + ======== CONTENTS ======== -- 2.5.2 -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
