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Date: Sun, 2 Feb 2025 17:29:21 -0500
From: Steven Rostedt <rostedt@goodmis.org>
To: Matthew Wilcox <willy@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>, Mathieu Desnoyers
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Subject: Re: [RFC][PATCH 1/2] sched: Extended scheduler time slice
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On Sun, 2 Feb 2025 07:22:08 +0000
Matthew Wilcox <willy@infradead.org> wrote:

> On Sat, Feb 01, 2025 at 10:22:08PM -0500, Steven Rostedt wrote:
> > And before seeing Peter's use of yield(), I was reluctant to use it for
> > the very same reasons you mentioned above. In my test programs, I was
> > simply using getuid(), as that was one of the quickest syscalls.  
> 
> Is getuid() guaranteed to issue a syscall?  It feels like the kind of
> information that a tricksy libc could cache.  Traditionally, I think
> we've used getppid() as the canonical "very cheap syscall" as no layer
> can cache that information.

Maybe that was what I used. Can't remember. And I think I even open
coded it using syscall() to not even rely on glibc.

-- Steve