[Pkg-haskell-maintainers] Bug#744240: logging alway makes 2 syscalls, even when nothing will be output

[Joey Hess]

Package: libghc-hslogger-dev
Version: 1.2.1+dfsg1-2+b1
Severity: normal

If I'm using hslogger for putting in debug statements, it would
be best for adding a statement to have minimal effect on CPU use.
This is not the case.

import System.Log.Logger

main = do
	noticeM "foo" "bar"
	main

straced yields:

clock_gettime(0x2 /* CLOCK_??? */, {0, 512615069}) = 0
clock_gettime(0x3 /* CLOCK_??? */, {0, 512642924}) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
rt_sigprocmask(SIG_BLOCK, [INT], [], 8) = 0
clock_gettime(0x2 /* CLOCK_??? */, {0, 513041060}) = 0
clock_gettime(0x3 /* CLOCK_??? */, {0, 513071921}) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
rt_sigprocmask(SIG_BLOCK, [INT], [], 8) = 0
clock_gettime(0x2 /* CLOCK_??? */, {0, 513472632}) = 0
clock_gettime(0x3 /* CLOCK_??? */, {0, 513498881}) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
rt_sigprocmask(SIG_BLOCK, [INT], [], 8) = 0
clock_gettime(0x2 /* CLOCK_??? */, {0, 513901179}) = 0
clock_gettime(0x3 /* CLOCK_??? */, {0, 513930296}) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
rt_sigprocmask(SIG_BLOCK, [INT], [], 8) = 0
clock_gettime(0x2 /* CLOCK_??? */, {0, 514334060}) = 0
clock_gettime(0x3 /* CLOCK_??? */, {0, 514358986}) = 0

The 2 time lookup calls should be avoided if no timestamp is going to be printed
out.

-- System Information:
Debian Release: jessie/sid
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 3.10-3-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.utf8, LC_CTYPE=en_US.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages libghc-hslogger-dev depends on:
ii  ghc [libghc-unix-dev-2.6.0.1-4f219]                    7.6.3-9
ii  libc6                                                  2.18-4
pn  libghc-base-dev-4.6.0.1-8aa5d                          <none>
pn  libghc-containers-dev-0.5.0.0-ab1da                    <none>
pn  libghc-directory-dev-1.2.0.1-91a78                     <none>
pn  libghc-mtl-dev-2.1.2-94c72                             <none>
ii  libghc-network-dev [libghc-network-dev-2.4.1.2-fc990]  2.4.1.2-1+b1
pn  libghc-old-locale-dev-1.0.0.5-6729c                    <none>
pn  libghc-process-dev-1.1.0.2-76e05                       <none>
pn  libghc-time-dev-1.4.0.1-10dc4                          <none>

libghc-hslogger-dev recommends no packages.

Versions of packages libghc-hslogger-dev suggests:
ii  libghc-hslogger-doc   1.2.1+dfsg1-2
ii  libghc-hslogger-prof  1.2.1+dfsg1-2+b1

-- no debconf information

-- 
see shy jo
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 811 bytes
Desc: Digital signature
URL: <http://lists.alioth.debian.org/pipermail/pkg-haskell-maintainers/attachments/20140411/1423da7d/attachment.sig>