On Tue, Oct 01 2024 at 05:45, Jeff Layton wrote: > On Mon, 2024-09-30 at 23:35 +0200, Thomas Gleixner wrote: >> > I certainly wouldn't rule out a workqueue job calling that function, >> > but this is something we do while dirtying an inode, and that's not >> > typically done in interrupt context. >> >> The reason I'm asking is that if it's always syscall context, >> i.e. write() or io_uring()/RPC request etc., then you can avoid the >> whole global floor value dance and make it strictly per thread, which >> simplifies the exercise significantly. >> > > I'm not sure I follow what you're proposing here. > > Consider two threads doing writes serially to different files. IOW, the > second thread enters the write() syscall after the first thread returns > from its write(). In that situation, the second timestamp mustn't > appear to be earlier than the first (assuming no backward clock jump, > of course). > > How would we ensure that with only per-thread structures? Bah. Right. Ignore my sleep deprived rambling.
