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Re: [Qemu-devel] FreeBSD clock_gettime()
From: |
Stefan Hajnoczi |
Subject: |
Re: [Qemu-devel] FreeBSD clock_gettime() |
Date: |
Tue, 2 Jun 2015 15:49:41 +0100 |
User-agent: |
Mutt/1.5.23 (2014-03-12) |
On Sun, May 31, 2015 at 07:11:25PM +0530, Sai Prajeeth wrote:
> I have done experiments and it seems that FreeBSD's libc function
> clock_gettime() results in a system call when running on QEMU whereas on
> hardware it does not. Does anybody know why? For those interested , you can
> find the clock_gettime libc call in freebsd source here:
> https://github.com/lattera/freebsd/blob/master/lib/libc/sys/clock_gettime.c
This is more of a FreeBSD kernel question than a QEMU question. I don't
have time to dig into the FreeBSD sources but you should be able to find
the answer there.
Check out the FreeBSD kernel's vdso implementation. Linux has something
similar, it's a library mapped into userspace processes that is provided
by the kernel. It includes low-level utilities that depend on the
specific kernel.
Stefan
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- Re: [Qemu-devel] FreeBSD clock_gettime(),
Stefan Hajnoczi <=