Re: tar x cpu bound

[Christoph Badura <bad%bsd.de@localhost>]

On Tue, May 13, 2025 at 10:06:16PM +0000, RVP wrote:
> qemu$ cd /tmp
> 
> qemu$ (pax -h; tar -h; xzcat ~/pkgsrc-HEAD.tar.xz) >/dev/null 2>&1

Is that so that the pax and tar executables are paged in entirely?

> qemu$ time -p xzcat ~/pkgsrc-HEAD.tar.xz | tar -xf -; rm -rf pkgsrc
> qemu$ time -p xzcat ~/pkgsrc-HEAD.tar.xz | pax -r 2>/dev/null; rm -rf pkgsrc

That times xzcat(1) not pax(1) or tar(1), doesn't it?  Don't you want:

xzcat ~/pkgsrc-HEAD.tar.xz | time -p tar -xf -; rm -rf pkgsrc
xzcat ~/pkgsrc-HEAD.tar.xz | time -p pax -r 2>/dev/null; rm -rf pkgsrc

--chris