On Wed, Feb 03, 2016 at 07:48:04PM -0800, Marc MERLIN wrote: > Hi Greg, > > Thanks for your quick reply. > > On Wed, Feb 03, 2016 at 07:07:45PM -0800, Greg Kroah-Hartman wrote: > > > Note that I have this problem with all USB sticks, not just this one > > > stick. > > > > What filesystem, vfat? What is the mount options you use for it? Try > > oops, forgot that: > /dev/sdc1 on /mnt/mnt type vfat > (rw,relatime,sync,uid=500,fmask=0022,dmask=0022,codepage=437,iocharset=utf8,shortname=mixed,errors=remount-ro) > > > turning off the 'flush' option if possible to try to match the same > > Windows options. > > legolas:~# mount -o remount,nosync /dev/sdc1 /mnt/mnt > > obviously makes things much faster, but by then the copy is acked > immediately (it's too fast to even measure the speed) but the usb key > keeps writing in the background for a while as expected. > > flush option does not seem enabled. > > Still, you're likely on the right track, something seems to wait for > each write to proceed before sending the next one.
What are you using to copy files? > Is there another option I can try? Turning off sync is the key thing here, without that on, things "seem" to be faster now. The real speed is the same, writes for your device is slow due to the flash chip, not the USB bandwidth. I'd try a "real" filesystem benchmark tool if you really want to know the speeds it can work at (fio is good.) I don't think there's much else we can suggest. greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
