>> On Sun, 09 Jan 2011 10:05:43 -0600, >> Stan Hoeppner <s...@hardwarefreak.com> said:
S> #! /bin/sh S> for k in $(ls *.JPG); do convert $k -resize 1024 $k; done Someone was ragging on you to let the shell do the file expansion. I like your way better because most scripting shells aren't smart enough to realize that when there aren't any .JPG files, I don't want the script to echo '*.JPG' as if that's actually useful. S> I use the above script to batch re-size digital camera photos after I S> dump them to my web server. It takes a very long time with lots of new S> photos as the server is fairly old, even though it is a 2-way SMP, S> because the script only runs one convert process at a time serially, S> only taking advantage of one CPU. First things first: are you absolutely certain that running two parallel jobs will exercise both CPUs? I've seen SMP systems that don't exactly live up to truth-in-advertising. If you stuff two "convert" jobs in the background and then run "top" (or the moral equivalent) do you SEE both CPUs being worked? Second: do you have "taskset" installed? If the work isn't being divided up the way you like, you can bind a process to a desired core: http://planet.admon.org/how-to-bind-a-certain-process-to-specified-core/ And last: if you're not using something like LVM, can you do anything to make sure you're not hitting the same disk? If all your new photos are on the same drive, any CPU savings you get from parallel processing will probably be erased by disk contention. Better yet, do you have enough memory to do the processing on a RAM-backed filesystem? -- Karl Vogel I don't speak for the USAF or my company If you're searching for the cause of a ghastly noise and find out that it's not the cat, leave the area immediately. --how to survive a horror movie -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20110110000500.46f09b...@kev.msw.wpafb.af.mil
