On Sun, 25 Feb 2024 15:03:02 -0500 Steven Rostedt <rost...@goodmis.org> wrote:
> *But* looking at this deeper, the commit_page may need a READ_ONCE() > but not for the reason you suggested. > > commit_page = cpu_buffer->commit_page; > commit_ts = commit_page->page->time_stamp; > > The commit_page above *is* used again, and we want commit_ts to be part > of the commit_page that was originally read and not a second reading. > > So, I think for the commit_page we do need a READ_ONCE() but that's > because it is referenced again just below it and we don't want the > compiler to read the memory location again for the second reference. Care to send a v2 patch that just adds READ_ONCE() for the commit_page, and change the change log stating that it is to fix the possibility that the time_stamp may come from a different page. -- Steve
