1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
|
[[!meta copyright="Copyright © 2011 Free Software Foundation, Inc."]]
[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
id="license" text="Permission is granted to copy, distribute and/or modify this
document under the terms of the GNU Free Documentation License, Version 1.2 or
any later version published by the Free Software Foundation; with no Invariant
Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license
is included in the section entitled [[GNU Free Documentation
License|/fdl]]."]]"""]]
[[!tag open_issue_xen]]
IRC, freenode, #hurd, 2011-11-02:
<youpi> btw, we have a performance issue with xen
<youpi> an lseek() call costs a huge lot
<youpi> like 1ms
<youpi> while the same costs just a few dozens µs with kvm
<youpi> there's of course the cost of switching between ring3, ring0,
ring1, ring0, ring3, but still
<gianluca> oh, nice.
<youpi> lseek is supposed to perform only a back&forth
<youpi> and I don't observe disk activity, so it's not waiting for the disk
to complete whatever atime change & such :)
<youpi> it was mentioned that perhaps xen in hvm mode with pv drivers would
be faster
<youpi> thanks to the ring3/"1" switching being done by the processor
<youpi> (and assuming npt)
<gianluca> hm
<gianluca> i'll look into that, sounds fun.
<gianluca> :)
<tschwinge> Here is a testcase:
http://www.gnu.org/software/hurd/open_issues/performance/io_system/binutils_ld_64ksec.html
[[performance/io_system/binutils_ld_64ksec]].
|
