Date: Mon, 30 Apr 2018 13:55:16 +1000 From: Patrick Oppenlander <patrick.oppenlander@...il.com> To: musl@...ts.openwall.com Subject: Re: Some questions On Mon, Apr 30, 2018 at 1:16 PM, Rich Felker <dalias@...c.org> wrote: > On Mon, Apr 30, 2018 at 12:52:06PM +1000, Patrick Oppenlander wrote: >> - Is there a way that spinlocks could be disabled or bypassed on >> uniprocessor systems? > > Whether locks are needed is a matter of whether there are multiple > threads, not whether it's uniprocessor or multiprocessor. For some > things where it's likely to matter (stdio, malloc, some other > internals), locks are already optimized out when there is only one > thread. In other cases it was deemed either too costly/difficult or > irrelevant to overall performance. I was talking about the case of a uniprocessor system running a multi theaded process. In that case the "spin" part of spinlock just burns time & electrons. The "lock" part obviously can't be omitted. Calling straight through to the kernel is the most efficient thing to do. Patrick
Powered by blists - more mailing lists
Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.