Messages in this thread | | | Date | Wed, 4 Oct 2017 08:14:31 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH 3/3] early_printk: Add simple serialization to early_vprintk() |
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On Wed, Oct 04, 2017 at 04:52:47PM +0200, Peter Zijlstra wrote: > On Wed, Oct 04, 2017 at 10:43:54AM -0400, Steven Rostedt wrote: > > > > My question is not about ordering, but about coherency. Can you have > > one CPU read a variable that goes into cache, and keep using the cached > > variable every time the program asks to read it, instead of going out > > to memory. > > No, not on a coherent system.
What Peter said. And if you use READ_ONCE() for the reads, than as far as I know, all the systems that the Linux kernel supports are coherent systems.
Thanx, Paul
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