Hi, On Mon, Jun 19, 2023 at 05:08:50PM +0200, Mark Wielaard wrote: > Just to let you know I am looking at this. But haven't made much > progress in understanding it yet. Thanks so much for the reproducer. I > have been able to see the (very slow) parsing of the core file with it. > > $ time ./mimic-systemd-coredump > [...] > real 3m35.965s > user 0m0.722s > sys 0m0.345s > > Note however that a lot of time is "missing". > And in fact running it again is fast!?! > > $ time ./mimic-systemd-coredump > real 0m0.327s > user 0m0.272s > sys 0m0.050s > > This is because of the kernel inode/dentry cache. > If I do $ echo 2 | sudo tee /proc/sys/vm/drop_caches > before running ./mimic-systemd-coredump it is always slow. > > I'll try to figure out what we do to make it so hard for the kernel to > do these lookups.
So I made a mistake here. Since I was testing on fedora 38 which has DEBUGINFOD_URLS set. Without DEBUGINFOD_URLS set there is no big slowdown. Do you have the DEBUGINFOD_URLS environment variable set? The real sd-coredump will not have DEBUGINFOD_URLS set (I hope). Thanks, Mark
