On Fri, Sep 18, 2020 at 06:25:02PM +0300, Tomi Valkeinen wrote: > Hi, > > Has anyone noticed that booting would have slowed down in 5.8 and in 5.9-rcs? I'm booting x15 with > my custom config builder, which uses omap2plus_defconfig as a base. I see: > > v5.7 > [ 0.597765] cpuidle: using governor menu > [ 0.793198] No ATAGs? > > [ 9.654611] Run /sbin/init as init process > > 5.8 > [ 0.616660] cpuidle: using governor menu > [ 4.439856] No ATAGs? > > [ 15.484710] Run /sbin/init as init process > > v5.9-rc5 > [ 0.706165] cpuidle: using governor menu > [ 6.761812] No ATAGs? > > [ 19.522536] Run /sbin/init as init process > > > So v5.7 boots quickly, and init starts around 9.6 secs. 5.8 is much slower, and 5.9-rc5 even slower. I've tracked this down to device_link_add_missing_supplier_links() taking about 40+ms to run, for every device added to the system. Given the large number of devices, this adds up to 10s on v5.9-rc5, when called during the initial of_platform_populate(). It doesn't seem there's a single culprit here (although I may have missed it), "just" lots of walks through the whole device tree that end up taking way too much time. I'm not planning to investigate this further at this point. > My config builder enables all kinds of debug options, so possibly it could be just more debug > features or such having been implemented, or enabled in omap2plus_defconfig... -- Regards, Laurent Pinchart
