I am experiencing slow I/O performance since kernel 5.0.1. File operations are roughly 10 times slower than they used to be using kernel up to 4.20. The problem is present when I use an USB pendrive, and does not happen when I copy a file from an internal SATA to another internal SATA hard disk. You can see the discussion in the dar (backup software) mailing list [1], because I first noticed the problem using dar, but then discovered that also usual file operations such as “cp” suffer the same problem. Steps to Reproduce: Copy a file (e.g. roughly 1GB) from an internal SATA HD to an USB pendrive using "cp", using kernel 5.0.1+ Actual Results: The file is copied in about 12 minutes Expected Results: The file is copied in about 1 minute (as it happens with kernel up to 4.20.13) Running Fedora 29 on a Desktop PC. Kernels found to be affected: e.g. 5.0.7, 5.0.9, 5.0.10, 5.0.13, 5.0.14, 5.0.17. [1]:[https://sourceforge.net/p/dar/mailman/dar-support/thread/d490b5733731cbbb526d759c858a4b11a52fd179.camel%40unipv.it/#msg36660380](dar mailing list archive)
On Thu, May 30, 2019 at 06:52:27AM +0000, bugzilla-daemon@bugzilla.kernel.org wrote: > https://bugzilla.kernel.org/show_bug.cgi?id=203757 > > Bug ID: 203757 > Summary: Slow I/O on USB media > Product: Drivers > Version: 2.5 > Kernel Version: 5.0.1 All USB bugs should be sent to the linux-usb@vger.kernel.org mailing list, and not entered into bugzilla. Please bring this issue up there, if it is still a problem in the latest kernel release.