* Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> [200923 11:14]: > Hi Tony, > > On Wed, Sep 23, 2020 at 10:07:58AM +0300, Tony Lindgren wrote: > > * Laurent Pinchart [200918 15:59]: > > > 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. > > > > Hmm so do you have some commit that causes this slowness? > > No, I haven't had time to bisect this. > > > In general, we should now be looking each device at module_init > > time only when configured in the dts. I guess it's possible we still > > have some extra walking of the whole device tree left but this sounds > > like a more generic issue though and not related to the omap dts > > conversion. > > There's a call to of_platform_populate() in pdata_quirks_init(), and > that takes between 5 and 10 seconds to run, depending on the board. If that is the issue we may be able to improve it a bit by probing the interconnects separately for less deferred probe cases. Regards, Tony
