[[!meta copyright="Copyright © 2010 Free Software Foundation, Inc."]] [[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable id="license" text="Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled [[GNU Free Documentation License|/fdl]]."]]"""]] [[!tag open_issue_gnumach]] IRC, unknown channel, unknown date: `cat < /dev/zero | cat > /dev/null` will eventually make the system crash, likewise when using a FIFO. hm... VM activity seems much higher when running fifo than pfinet... may be the cause "zero filled" and "page faults" are serveral times higher with pipe than with pfinet (cow faults however are about the same...) pflocal is about the same as fifo no, because it usually takes like 20 minutes until it crashes, sometimes much longer not sure, but the longest so far was in the range of hours IIRC I think I never tested what happens on "cat /dev/zero >/dev/null"... another thing yet to try Linux BTW seems to employ some major VM trickery in this case -- dd shows a transfer rate of 10 GB/s... no, no anomalies in vmstat the only observation I made is that number of page faults and some other number rise pretty quickly with pflocal and fifo, but not with pfinet I guess that's somehow related to the fact that pfinet doesn't crash -- though I guess the difference is simply that pfinet is way slower... (haven't checked that, though) BTW, I'm not sure you got it right: the test case is "cat /dev/zero|cat >/dev/null", *not* "cat /dev/zero >/dev/null" OK, "cat /dev/zero|tail -c 1" also crashes, so it's definitely not related to /dev/null "dd if=/dev/zero|tail -c 1" crashes as well but "tail -c 1 /dev/zero" doesn't seem to cool... running multiple instances of the pipe test also considerably speeds up the crash