From e314c1fc4cbdf8d7172fb6f8b87b127b21dd26c0 Mon Sep 17 00:00:00 2001
From: John Reiser <jreiser@bitwagon.com>
Date: Tue, 5 Feb 2013 21:47:40 +0330
Subject: [PATCH 12/18] Factor out unnecessary logger calls (#875356)
Numerous invocations of logger bogged down os-prober on system with
large numbers of partitions. Refactored to reduce the total number of
unique invocations to increase speed.
Resolves: rhbz#875356
---
common.sh | 24 ++++++++++++++++--------
linux-boot-prober | 11 +++++++++++
os-prober | 12 +++++++++++-
3 files changed, 38 insertions(+), 9 deletions(-)
diff --git a/common.sh b/common.sh
index 1dbf7a3..7fcae5a 100644
--- a/common.sh
+++ b/common.sh
@@ -62,10 +62,14 @@ cache_progname() {
esac
}
-log() {
- cache_progname
- logger -t "$progname" "$@"
-}
+# fd_logger: bind value now, possibly after assigning default.
+eval '
+ log() {
+ cache_progname
+ echo "$progname: $@" 1>&'${fd_logger:=9}'
+ }
+'
+export fd_logger # so subshells inherit current value by default
error() {
log "error: $@"
@@ -81,10 +85,14 @@ debug() {
fi
}
-result () {
- log "result:" "$@"
- echo "$@"
-}
+# fd_result: bind value now, possibly after assigning default.
+eval '
+ result() {
+ log "result:" "$@"
+ echo "$@" 1>&'${fd_result:=1}'
+ }
+'
+export fd_result # so subshells inherit current value by default
# shim to make it easier to use os-prober outside d-i
if ! type mapdevfs >/dev/null 2>&1; then
diff --git a/linux-boot-prober b/linux-boot-prober
index 57bf245..3b89750 100755
--- a/linux-boot-prober
+++ b/linux-boot-prober
@@ -1,4 +1,12 @@
#!/bin/sh
+
+# dash shell does not have "{varname}>&1" feature that bash shell has
+# for auto-assignment of new filedescriptors.
+# It is cumbersome to write the 'eval' to use our own variables in redirections.
+# Therefore use fixed numbers.
+export fd_result=3 # file descriptor for external results
+export fd_logger=9 # file descriptor for input to logger
+
. /usr/share/os-prober/common.sh
set -e
@@ -147,6 +155,7 @@ if ! mapped="$(mapdevfs "$partition")"; then
continue
fi
+( (
if ! grep -q "^$mapped " "$OS_PROBER_TMP/mounted-map"; then
for test in /usr/lib/linux-boot-probes/*; do
if [ -x $test ] && [ -f $test ]; then
@@ -186,3 +195,5 @@ else
fi
fi
fi
+) 9>&1 | logger 1>&- # fd_logger
+) 3>&1 # fd_result
diff --git a/os-prober b/os-prober
index f5052af..4b371d6 100755
--- a/os-prober
+++ b/os-prober
@@ -1,7 +1,14 @@
#!/bin/sh
set -e
-. /usr/share/os-prober/common.sh
+# dash shell does not have "{varname}>&1" feature that bash shell has
+# for auto-assignment of new filedescriptors.
+# It is cumbersome to write the 'eval' to use our own variables in redirections.
+# Therefore use fixed numbers.
+export fd_result=3 # file descriptor for external results
+export fd_logger=9 # file descriptor for input to logger
+
+ . /usr/share/os-prober/common.sh
newns "$@"
require_tmpdir
@@ -129,6 +136,7 @@ fi
: >"$OS_PROBER_TMP/btrfs-vols"
+( (
for partition in $(partitions); do
if ! mapped="$(mapdevfs "$partition")"; then
log "Device '$partition' does not exist; skipping"
@@ -193,3 +201,5 @@ for partition in $(partitions); do
fi
fi
done
+) 9>&1 | logger 1>&- # fd_logger
+) 3>&1 # fd_result
--
2.5.5