Forgot to attach the patch. Classic. Best regards, Manolis
On Mon, 8 Jan 2024 at 00:01, Manolis Stamatogiannakis <msta...@gmail.com> wrote: > Hi Steinar, > > Thanks for the fast response. > > On Sun, 7 Jan 2024 at 20:48, Steinar H. Gunderson <se...@debian.org> > wrote: > >> On Sun, Jan 07, 2024 at 08:21:35PM +0200, Manolis Stamatogiannakis wrote: >> > I am trying to get plocate to run on an old ARM-based NAS running Debian >> > bookworm. Building the database with updatedb works fine, but plocate >> > command itself blocks forever without giving any results back. >> > >> > I attached gdb to the process, and the source of the problem appears to >> > be related to the use of io_uring. >> > >> > Trying to understand what is going on, I ran plocate under strace as >> > root. Surprisingly, it ran without blocking. >> >> This is interesting, but fundamentally pretty impossible to debug from my >> side. It sounds very much like a timing-related bug, which is probably why >> strace affects it (everything goes much slower); another common case is >> that >> one attaches strace to a running process, which causes the io_uring >> syscall >> to return EINTR, which gets things running again. >> >> Is this reproducible every time? >> > > Yes, it is reproducible every time. > > I understand this may be very hard to reproduce/debug on your side without > access to similar hardware. > One could probably try reproducing the behaviour with cpulimit + QEMU, but > it's not a guaranteed > hit, and I don't really expect anyone to spend their time on that. > > For now, I'm quite content with having a workaround, and I opened the bug > mostly to have the > issue and the workaround documented for anyone else that may be affected. > If more people turn out to have the same issue on armel, we'll probably > also have more input for > a source-based fix. > > So, feel free to mark this as unreproducible for now. > > Since you are also the author of plocate, it may make sense to expose the > -DWITHOUT_URING flag > through meson to make compiling without io_uring a bit more > straightforward. (Trival patch attached.) > > > >> >> > * reports an error for not being able to access the database when run >> > under strace as user (which sounds like the expected behaviour) >> >> Yes, this is expected. >> >> > Architecture: armel (armv5tel) >> > Kernel: Linux 6.1.0-17-marvell (UP) >> >> Is this even supported by Debian anymore? >> >> > It's definitely a niche platform, but it appears to be supported: > https://www.debian.org/releases/stable/i386/ch02s01.en.html > > >> /* Steinar */ >> -- >> Homepage: https://www.sesse.net/ > > > > Best regards, > Manolis >
plocate-without-uring.diff
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