Currently, udev-cache system configurations are compared as shell string variables, read into memory with the readfiles() function. This is more complex, and significantly (27-41%) slower, than comparing them using `cmp`. (Performance was verified on both Cortex-A9 and Intel Nehalem systems.)
So just use cmp. This requires a few other small changes: exclude /proc/atags from CMP_FILE_LIST if it doesn't exist to avoid errors in `cat` and `cmp`. `cmp -q` doesn't exist in busybox, so instead, redirect output to /dev/null. Signed-off-by: Richard Tollerton <[email protected]> --- meta/recipes-core/udev/udev/init | 29 +++++++---------------------- meta/recipes-core/udev/udev/udev-cache | 17 +++-------------- 2 files changed, 10 insertions(+), 36 deletions(-) diff --git a/meta/recipes-core/udev/udev/init b/meta/recipes-core/udev/udev/init index d26cbfc..ee79670 100644 --- a/meta/recipes-core/udev/udev/init +++ b/meta/recipes-core/udev/udev/init @@ -20,17 +20,6 @@ SYSCONF_TMP="/dev/shm/udev.cache" [ -f /etc/udev/udev.conf ] && . /etc/udev/udev.conf [ -f /etc/default/rcS ] && . /etc/default/rcS -readfiles () { - READDATA="" - for filename in $@; do - if [ -r $filename ]; then - while read line; do - READDATA="$READDATA$line" - done < $filename - fi - done -} - kill_udevd () { pid=`pidof -x udevd` [ -n "$pid" ] && kill $pid @@ -63,14 +52,12 @@ case "$1" in # Cache handling. # A list of files which are used as a criteria to judge whether the udev cache could be reused. - CMP_FILE_LIST="/proc/version /proc/cmdline /proc/devices /proc/atags" + CMP_FILE_LIST="/proc/version /proc/cmdline /proc/devices" + [ -f /proc/atags ] && CMP_FILE_LIST="$CMP_FILE_LIST /proc/atags" if [ "$DEVCACHE" != "" ]; then if [ -e $DEVCACHE ]; then - readfiles $CMP_FILE_LIST - NEWDATA="$READDATA" - readfiles "$SYSCONF_CACHED" - OLDDATA="$READDATA" - if [ "$OLDDATA" = "$NEWDATA" ]; then + cat -- "$CMP_FILE_LIST" > "$SYSCONF_TMP" + if cmp $SYSCONF_CACHED $SYSCONF_TMP >/dev/null; then tar xmf $DEVCACHE -C / -m not_first_boot=1 [ "$VERBOSE" != "no" ] && echo "udev: using cache file $DEVCACHE" @@ -80,17 +67,15 @@ case "$1" in if [ "$VERBOSE" != "no" ]; then echo "udev: udev cache not used" echo "udev: we use $CMP_FILE_LIST as criteria to judge whether the cache /dev could be resued" - echo "udev: olddata: $OLDDATA" - echo "udev: newdata: $NEWDATA" + echo "udev: cached sysconf: $SYSCONF_CACHED" + echo "udev: current sysconf: $SYSCONF_TMP" fi - echo "$NEWDATA" > "$SYSCONF_TMP" fi else if [ "$ROOTFS_READ_ONLY" != "yes" ]; then # If rootfs is not read-only, it's possible that a new udev cache would be generated; # otherwise, we do not bother to read files. - readfiles $CMP_FILE_LIST - echo "$READDATA" > "$SYSCONF_TMP" + cat -- "$CMP_FILE_LIST" > "$SYSCONF_TMP" fi fi fi diff --git a/meta/recipes-core/udev/udev/udev-cache b/meta/recipes-core/udev/udev/udev-cache index a1410f5..e0e1c39 100644 --- a/meta/recipes-core/udev/udev/udev-cache +++ b/meta/recipes-core/udev/udev/udev-cache @@ -21,20 +21,10 @@ SYSCONF_CACHED="/etc/udev/cache.data" SYSCONF_TMP="/dev/shm/udev.cache" # A list of files which are used as a criteria to judge whether the udev cache could be reused. -CMP_FILE_LIST="/proc/version /proc/cmdline /proc/devices /proc/atags" +CMP_FILE_LIST="/proc/version /proc/cmdline /proc/devices" +[ -f /proc/atags ] && CMP_FILE_LIST="$CMP_FILE_LIST /proc/atags" [ -f /etc/default/udev-cache ] && . /etc/default/udev-cache -readfiles () { - READDATA="" - for filename in $@; do - if [ -r $filename ]; then - while read line; do - READDATA="$READDATA$line" - done < $filename - fi - done -} - if [ "$ROOTFS_READ_ONLY" = "yes" ]; then [ "$VERBOSE" != "no" ] && echo "udev-cache: read-only rootfs, skip generating udev-cache" exit 0 @@ -43,8 +33,7 @@ fi if [ "$DEVCACHE" != "" -a -e "$SYSCONF_TMP" ]; then echo "Populating dev cache" udevadm control --stop-exec-queue - readfiles $CMP_FILE_LIST - echo "$READDATA" > "$SYSCONF_TMP" + cat -- $CMP_FILE_LIST > "$SYSCONF_TMP" find /dev -xdev \( -type b -o -type c -o -type l \) | cut -c 2- \ | xargs tar cf "${DEVCACHE_TMP}" -T- gzip < "${DEVCACHE_TMP}" > "$DEVCACHE" -- 2.1.3 -- _______________________________________________ Openembedded-core mailing list [email protected] http://lists.openembedded.org/mailman/listinfo/openembedded-core
