Package: apt-proxy
Version: 1.9.25
Severity: important
Tags: patch
Hi,
On User Mode Linux, because of the fact that all system calls are
thunked, the trick that you use to "ignore" the standard output actually
takes a lot of time and CPU. By redirecting stdout to /dev/null the
performance of apt-proxy improves significantly. In the attached patch,
I do exactly that. I have not played with stderr, since there is
commented out debugging code that will use the value that is calculated.
That said, if it could be removed, I would lose no sleep ;-)
Anyway, timings on my system (second run for both, so they are both
running off of disk cache):
old: Fetched 19.7MB in 23s (830kB/s)
new: Fetched 19.7MB in 15s (1242kB/s)
This will also make a difference on non-UML hosts, but the change will
probably not be so great.
Cheers,
Paul
-- System Information:
Debian Release: 3.1
APT prefers unstable
APT policy: (500, 'unstable'), (101, 'experimental')
Architecture: i386 (i686)
Kernel: Linux 2.6.10-1-k7
Locale: LANG=C, LC_CTYPE=C (charmap=ANSI_X3.4-1968)
Versions of packages apt-proxy depends on:
ii bzip2 1.0.2-3 high-quality block-sorting file co
ii debconf 1.4.42 Debian configuration management sy
ii logrotate 3.7-2 Log rotation utility
ii python 2.3.4-6 An interactive high-level object-o
ii python-apt 0.5.10 Python interface to libapt-pkg
ii python-bsddb3 3.3.0-6 Python interface to libdb3
ii python-twisted 1.3.0-6 Event-based framework for internet
-- debconf information:
apt-proxy/upgrading-v2:
apt-proxy/upgrading-v2-result:
Index: apt_proxy/apt_proxy.py
===================================================================
RCS file: /cvsroot/apt-proxy/apt-proxy/apt_proxy/apt_proxy.py,v
retrieving revision 1.104
diff -u -r1.104 apt_proxy.py
--- apt_proxy/apt_proxy.py 26 Jan 2005 10:31:52 -0000 1.104
+++ apt_proxy/apt_proxy.py 30 Jan 2005 10:00:29 -0000
@@ -148,7 +148,8 @@
return
log.debug("starting verification: " + exe + " " + str(args))
- self.process = reactor.spawnProcess(self, exe, args)
+ self.nullhandle = open("/dev/null", "w")
+ self.process = reactor.spawnProcess(self, exe, args, childFDs = {
0:"w", 1:self.nullhandle.fileno(), 2:"r" })
self.laterID = reactor.callLater(self.factory.timeout, self.timedout)
def connectionMade(self):
