On Tue, Mar 10, 2020 at 03:05:57PM +0000, David Laight wrote: > From: Marco Elver > > Sent: 10 March 2020 14:10 > ... > > FWIW, for writes we're already being quite generous, in that plain > > aligned writes up to word-size are assumed to be "atomic" with the > > default (conservative) config, i.e. marking such writes is optional. > > Although, that's a generous assumption that is not always guaranteed > > to hold (https://lore.kernel.org/lkml/20190821103200.kpufwtviqhpbuv2n@willie-the-truck/). > > Remind me to start writing everything in assembler. Been there, done that. :-/ > That and to mark all structure members 'volatile'. Indeed. READ_ONCE() and WRITE_ONCE() get this same effect, but without pessimizing non-concurrent accesses to those same members. Plus KCSAN knows about READ_ONCE(), WRITE_ONCE(), and also volatile members. Thanx, Paul
