(switched to email. Please respond via emailed reply-to-all, not via the bugzilla web interface). On Tue, 15 Mar 2011 15:55:52 GMT bugzilla-daemon@xxxxxxxxxxxxxxxxxxx wrote: > https://bugzilla.kernel.org/show_bug.cgi?id=31142 > > Summary: Large write to USB stick freezes unrelated tasks for a > long time > Product: IO/Storage > Version: 2.5 > Kernel Version: 2.6.38-rc8 > Platform: All > OS/Version: Linux > Tree: Mainline > Status: NEW > Severity: normal > Priority: P1 > Component: Block Layer > AssignedTo: axboe@xxxxxxxxx > ReportedBy: avillaci@xxxxxxxxxxxxxxxxxxxxxxx > Regression: No > > > Created an attachment (id=50902) > --> (https://bugzilla.kernel.org/attachment.cgi?id=50902) > kernel backtraces from hung Eclipse task while writing to usb stick > > System is Fedora 14 x86_64 with 4 GB RAM, running vanilla kernel 2.6.38-rc8. > > I have a USB 2.0 high-speed memory stick with around 7.5 GB of space. Whenenver > I write a large amount of data (several GBs of files) through any means (cp, > nautilus GUI, etc), I notice some large applications that I consider unrelated > to the I/O operation (Firefox web browser, Thunderbird email viewer, Eclipse > IDE) may randomly freeze whenever I try to interact with them. I use Compiz, > and I notice the apps getting grayed out, but I have also seen the freeze > happening with Metacity and Gnome-shell, so I believe the window manager is > irrelevant. Sometimes other smaller tasks (gnome-terminal, gedit) also freeze. > For Eclipse, the hang also cause a series of kernel backtraces, attached to > this report. The hang usually lasts for several tens of seconds, and may freeze > and unfreeze several times while the file copying to USB takes place. All of > the hung applications unfreeze themselves after write activity (as seen from > the LED in the memory stick) ceases. > > Reproducibility: always (with sufficiently large bulk write) > To reproduce: > 1) have an usb stick with several GB of free space, with any filesystem (tried > vfat and udf) > 2) prepare several gb of files to copy from hard disk to usb stick > 3) start large application (firefox, eclipse, or thunderbird) > 4) check that application is responsive before file copy starts > 5) insert usb stick and (auto)mount it. Previously started app is still > responsive. > 6) start file copy to usb stick with any command > 7) attempt to interact with chosen application during the entirety of the file > write > Expected result: I/O to usb stick takes place in background, unrelated apps > continue to be responsive in foreground. > Actual result: some large tasks freeze for tens of seconds while write takes > place. > > Feel free to reassign this bug to a different category. It involves I/O, block, > USB, and mmap. rofl, will we ever fix this. Please enable sysrq and do a sysrq-w when the tasks are blocked so we can find where things are getting stuck. Please avoid email client wordwrapping when sending us the sysrq output. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>