bug#39341: Installer using 100% of a CPU core

[pelzflorian (Florian Pelz)]

On Wed, Apr 28, 2021 at 09:02:10AM +0200, pelzflorian (Florian Pelz) wrote:
> On Tue, Apr 27, 2021 at 11:26:41PM +0200, Ludovic Courtès wrote:
> > 165   openat(AT_FDCWD, 
> > "/gnu/store/qz3zdrz12rxawlkvah9qjhjyf6fh1v98-xkeyboard-config-2.31/share/X11/xkb/symbols/inet",
> >  O_RDONLY) = 22
> > 165   fstat(22, {st_mode=S_IFREG|0444, st_size=64040, ...}) = 0
> > 165   mmap(NULL, 64040, PROT_READ, MAP_SHARED, 22, 0) = 0x7f50d23b5000
> > 165   brk(0x12bb000)                    = 0x12bb000
> > 165   munmap(0x7f50d23b5000, 64040)     = 0
> > 165   close(22)                         = 0
> > 165   epoll_ctl(3, EPOLL_CTL_DEL, 17, NULL) = 0
> > 165   close(17)                         = 0
> > 165   getpid()                          = 165
> > 165   unlink("/tmp/kmscon-165-keymap-update") = 0
> > 165   mknod("/tmp/kmscon-165-keymap-update", S_IFIFO|0700) = 0
> > 165   openat(AT_FDCWD, "/tmp/kmscon-165-keymap-update", 
> > O_RDONLY|O_NONBLOCK) = 17
> > 165   epoll_ctl(3, EPOLL_CTL_ADD, 17, {EPOLLIN, {u32=19410896, 
> > u64=19410896}}) = 0
> > --8<---------------cut here---------------end--------------->8---
> > 
> > The last lines show that we delete the FIFO from the poll set, close the
> > FIFO, recreate it, and re-add it to the poll set.
> 
> I got:
> 
> 231   openat(AT_FDCWD, 
> "/gnu/store/qz3zdrz12rxawlkvah9qjhjyf6fh1v98-xkeyboard-config-2.31/share/X11/xkb/symbols/inet",
>  O_RDONLY) = 31
> 231   fstat(31, {st_mode=S_IFREG|0444, st_size=64040, ...}) = 0
> 231   mmap(NULL, 64040, PROT_READ, MAP_SHARED, 31, 0) = 0x7f1b1f5c7000
> 231   munmap(0x7f1b1f5c7000, 64040)     = 0
> 231   close(31)                         = 0
> 231   epoll_ctl(3, EPOLL_CTL_DEL, 26, NULL) = 0
> 231   close(26)                         = 0
> 231   getpid()                          = 231
> 231   unlink("/tmp/kmscon-231-keymap-update") = 0
> 231   mknod("/tmp/kmscon-231-keymap-update", S_IFIFO|0700) = 0
> 231   openat(AT_FDCWD, "/tmp/kmscon-231-keymap-update", O_RDONLY|O_NONBLOCK) 
> = 26
> 231   epoll_ctl(3, EPOLL_CTL_ADD, 26, {EPOLLIN, {u32=9609568, u64=9609568}}) 
> = 0
> 231   epoll_wait(3, [{EPOLLIN, {u32=8123856, u64=8123856}}], 32, -1) = 1
> 231   read(14, "\2\0\0\0 
> \0\0\0000\373{\0\0\0\0\0\326\0\0\0^\335\t\0\347,\0\0]\0\0\0", 1024) = 32
> 231   ioctl(14, DRM_IOCTL_MODE_PAGE_FLIP, 0x7fff282d6b50) = 0
> 
> Slightly different.  This is the next occurrence after the pci05\0fr.

The brk does happen, just later, if it is important.

Regards,
Florian