Hi Olivier, Thanks for experimenting on your end to rule out any X server issues. I was able to match your results and launch 512 instances of vkcube after making sure that Xserver (1.21.1.8) has inherited the higher "max open files" limit. I really appreciate help from you, Adam and Alan.
Anuj On Wed, Aug 16, 2023 at 12:46 AM Olivier Fourdan <ofour...@redhat.com> wrote: > > Hi Anuj, > > On Mon, Aug 14, 2023 at 8:27 PM Anuj Phogat <anuj.pho...@gmail.com> wrote: >> >> - I'm still getting the "_XSERVTransSocketUNIXAccept: accept() failed" error >> after launching ~ 256 instances of vkcube. I was able to find the root >> cause of error after patching libxtrans based on Adam's suggestion: >> "_XSERVTransSocketUNIXAccept: accept() failed (Too many open files)" >> - Based on the hint from the error string, I changed the system wide limit to >> increase the maximum number of open files allowed from default 1024 to >> 'ulimit -n' confirmed the new limit. But, this change doesn't change >> the error past launching ~ 256 instances of vkcube. >> - I hit the same error but at ~330 instances when I try to run glxgears. >> >> Questions: >> What am I missing when changing the open files limit ? > > > Make sure the X process has inherited that limit, depending on how/where you > bumped the limit, the X server process may not have that applied. > > You can check using the /proc filesystem on Linux: > > $ cat /proc/$(pidof Xorg)/limits > >> What else can I try to get past this error ? > > > If you can get 330 instances of glxgears, it means that you are already past > the 256 limit, hence the maxclients worked. > > It is worth noting that the limit applies to all X11 clients, so if you run a > window manager, an xterm, etc, everything counts. > > Also if a client opens more than one connection to the X server, that also > counts. So you can expect that a limit of 512 might give you a lower actual > limit. > >> >> Should I reopen xserver issue [1] or create a new issue to track it ? > > > I doubt that this is an X server issue. > > FWIW, I just tried here with Xwayland rootful and was able to run 474 > instances of vkcube on a rootful stanlone Xwayland instance: > > $ Xwayland -maxclients 512 -decorate :12 7 > $ for i in $(seq 1 512); do DISPLAY=:12 vkcube& done > $ ps aux | grep vkcube | wc -l > 474 > > I have seen some "Maximum number of clients reached" errors while the vkcube > instances were spawning en masse, so I suspect maybe the vulkan > implementation is opening a connection to the display for some reason > temporarily, so having those start all at once may lead to a lower actual > limit of clients.. > > To confirm that theory, I dedid the same test waiting a bit between each > instance of vkcube. > > And nowI can reach the limit of 512: > > $ for i in $(seq 1 512); do DISPLAY=:12 vkcube; sleep .2 & done > $ ps aux | grep vkcube | wc -l > 512 > > So yeah, no bug in the Xserver AFAICS. > > This is with: > > $ cat /proc/$(pidof Xwayland)/limits > Limit Soft Limit Hard Limit Units > Max cpu time unlimited unlimited seconds > Max file size unlimited unlimited bytes > Max data size unlimited unlimited bytes > Max stack size 8388608 unlimited bytes > Max core file size unlimited unlimited bytes > Max resident set unlimited unlimited bytes > Max processes 62319 62319 processes > Max open files 16777216 16777216 files > Max locked memory 8388608 8388608 bytes > Max address space unlimited unlimited bytes > Max file locks unlimited unlimited locks > Max pending signals 62319 62319 signals > Max msgqueue size 819200 819200 bytes > Max nice priority 0 0 > Max realtime priority 0 0 > Max realtime timeout unlimited unlimited us > >> [1] : https://gitlab.freedesktop.org/xorg/xserver/-/issues/1310 > > > Cheers > Olivier > >
