>> Obviously fixing iptables is desirable, but is it possible to improve >> performance >> of busybox modprobe? Looking at strace the big difference seems to be the >> read of the various files, busybox apparently using lots of getc()? >> >> Any thoughts on a solution? > > > Apparently upstream tools now use some sort of binary indexed files > which allow search to be sped up:
Hi, thanks for not forgetting about this. > There is no fast fix for this: we will need to implement indexed binary files > to match upstream speed. Hmm, interesting. My first estimate was that the per character reading of the file was slow and hammering me here? I am on linux and noticed that there was a (commented out) chunk of code in busybox to use platform line reads, but I have not experimented with whether that offers a performance difference I'm running from an SLC CF card, so if my modules.alias is 137KB and takes around 0.05s to read, then this is very roughly 2.7MB/s, which seems a touch on the slow side. Using "dd" I get approximately 11.3MB/s from the raw device, but this isn't including the overhead of my filesystem (squashfs+aufs). Additionally I'm running the modprobe test many times in a row and I might expect the block cache to eliminate the disk read time on subsequent runs? Therefore low couple of MB/s seems rather a poor read speed for busybox processing modules.dep from cache? I still wonder if the single character read is the bottleneck here? (I notice it's also used in sed, I could perhaps benchmark that for comparison...) Thanks for your thoughts Ed W _______________________________________________ busybox mailing list [email protected] http://lists.busybox.net/mailman/listinfo/busybox
