On 2022-04-26 12:47:53 -0500, Nicholas Geovanis wrote: > On Tue, Apr 26, 2022 at 12:37 PM Nicholas Geovanis <nickgeova...@gmail.com> > wrote: > > > On Tue, Apr 26, 2022 at 8:45 AM Vincent Lefevre <vinc...@vinc17.net> > > wrote: > > > >> On an ext4 filesystem, I got a file born 30 seconds after its > >> actual creation. Is this a bug? > >> > > > > Only experimentation can really back me up on this, but consider the > > following: > > > > Every time you use the "|" operator or the ";" separator on a command-line, > > new processes are being spawned. Which wait to be dispatched on a core. > > But you are not serializing the dispatch of those processes, and > > especially with > > 16 fast cores, you can't predict their order of execution. > > > > A couple more observations: > (1) It looks like you're trying to observe behavior in the very same > filesystem in which > the running executable is loaded from and its log files are being > written-to. That's > alot of variables in motion at once. > > (2) Yes, the "|" is in a sense serializing I/O in "lt|head". But the > filesystem is syncing > buffered and disk-based content separately from that.
There are no parallel writes to the file, i.e. everything is serialized from this point of view. -- Vincent Lefèvre <vinc...@vinc17.net> - Web: <https://www.vinc17.net/> 100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/> Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)
