lkml.org 
[lkml]   [2019]   [Dec]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: AW: Slow I/O on USB media after commit f664a3cc17b7d0a2bc3b3ab96181e1029b0ec0e6
    From
    Date
    Il giorno lun, 23/12/2019 alle 12.22 -0500, Theodore Y. Ts'o ha
    scritto:
    > On Mon, Dec 23, 2019 at 05:29:27PM +0100, Andrea Vai wrote:
    > > I run the cp command from a bash script, or from a bash shell. I
    > don't
    > > know if this answer your question, otherwise feel free to tell me
    > a
    > > way to find the answer to give you.
    >
    > What distro are you using, and/or what package is the cp command
    > coming from, and what is the package name and version?

    Fedora 30

    $ rpm -qf `which cp`
    coreutils-8.31-6.fc30.x86_64

    >
    > Also, can you remind me what the bash script is and how many files
    > you are copying?

    basically, it's:

    mount UUID=$uuid /mnt/pendrive
    SECONDS=0
    cp $testfile /mnt/pendrive
    umount /mnt/pendrive
    tempo=$SECONDS

    and it copies one file only. Anyway, you can find the whole script
    attached.


    >
    > Can you change the script so that the cp command is prefixed by:
    >
    > "strace -tTf -o /tmp/st "
    >
    > e.g.,
    >
    > strace -tTf -o /tmp/st cp <args>
    >
    > And then send me
    btw, please tell me if "me" means only you or I cc: all the
    recipients, as usual

    > the /tmp/st file. This will significantly change the
    > time, so don't do this for measuring performance. I just want to
    > see
    > what the /bin/cp command is *doing*.

    I will do it, but I have a doubt. Since the problem doesn't happen
    every time, is it useful to give you a trace of a "fast" run? And, if
    it's not, I think I should measure performance with the trace command
    prefix, to identify a "slow" run to report you. Does it make sense?

    Thanks,
    Andrea
    [unhandled content-type:application/x-shellscript]
    \
     
     \ /
      Last update: 2019-12-23 19:46    [W:4.762 / U:0.216 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site