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Rockbox mail archiveSubject: Re: problems copying over many filesRe: problems copying over many files
From: Johan Vromans <jvromans_at_squirrel.nl>
Date: Sat, 29 Mar 2003 16:43:01 +0100 "Gerald Clark" <gerald_clark_at_mindspring.com> writes: > Are you running Linux and USB1 ? > I suspect it starts out fast as it fills > Many megs of buffers. When it runs out of buffers, it starts writing them. > This is the long pause. The following experiment confirms this. Note these are figures for USB 2.0. Also note, that this is Linux kernel 2.4.20. # mount /dev/sdd1 /mnt/tmp Copy a directory with 120Mb (19 files): # time cp *.mp3 /mnt/tmp/tmp/ 0.020u 1.790s 0:28.33 6.3% 0+0k 0+0io 138pf+0w Quickly, do it again: # time cp *.mp3 /mnt/tmp/tmp/ 0.010u 1.130s 0:03.21 35.5% 0+0k 0+0io 138pf+0w Apparently, most of the data is still in the buffer. Therefore, the umount needs time to flush: # time umount /dev/sdd1 0.000u 0.410s 0:22.20 1.8% 0+0k 0+0io 145pf+0w These are the figures for USB 1: # mount /dev/sdd1 /mnt/tmp # cp *.mp3 /mnt/tmp/tmp/ 0.030u 1.130s 3:00.24 0.6% 0+0k 0+0io 130pf+0w # time umount /dev/sdd1 0.010u 0.340s 2:29.06 0.2% 0+0k 0+0io 145pf+0w -- Johan Received on 2003-03-29 Page template was last modified "Tue Sep 7 00:00:02 2021" The Rockbox Crew -- Privacy Policy |