On Mon, 25 Nov 2019 at 23:31, Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx> wrote: > > > On 11/25/19 3:39 PM, Steven Rostedt wrote: > > On Mon, 25 Nov 2019 15:30:39 +0100 > > Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx> wrote: > > > >> It seems that commit 0e4a459f56c3 ("tracing: Remove unnecessary DEBUG_FS > >> dependency") disabled DEBUG_FS also in some other ARM defconfigs. > >> > >> For some of them it may be a correct change but a preferred way to > >> introduce such changes would be to: > >> > >> - add explicit CONFIG_DEBUG_FS=y instances to all affected defconfigs > >> while removing DEBUG_FS selection from TRACING config item > >> > > > > I strongly disagree. It was wrong to assume DEBUG_FS is attached to > > TRACING. If someone wanted DEBUG_FS in their def config, they should > > have added it specifically. The addition of DEBUG_FS to defconfigs no > > There is a theory and a practice. > > In theory you are are correct. ;-) > > In practice people don't manually edit configuration files nowadays. > > They do 'make menuconfig' and enable what they need and disable what > they do not need. Then they do 'make savedefconfig' and copy resulting > "stripped" defconfig file as their new platform defconfig. As a result > defconfigs rely on many default settings (also they explicitly disable > only items that are enabled by default but you don't want them). I agree with Bartłomiej. Your interpretation Steven essentially prohibits any use of savedefconfig to trim automatically the config from unneeded options. Therefore many defconfigs which do not have DEBUG_FS or other options directly, but they want it. Some time ago I had patches removing specific non-existing options from defconfigs. For each option I provided a rationale that it is gone/etc so let's remove it from defconfig. Most of maintainers picked them up but few (2-3?) instead run savedefconfig to clean up everything automatically. Best regards, Krzysztof