On Wed, Jan 12, 2022 at 11:06 AM Suren Baghdasaryan <surenb@xxxxxxxxxx> wrote: > > On Wed, Jan 12, 2022 at 11:04 AM Eric Biggers <ebiggers@xxxxxxxxxx> wrote: > > > > On Wed, Jan 12, 2022 at 10:53:48AM -0800, Suren Baghdasaryan wrote: > > > On Wed, Jan 12, 2022 at 10:44 AM Eric Biggers <ebiggers@xxxxxxxxxx> wrote: > > > > > > > > On Wed, Jan 12, 2022 at 10:26:08AM -0800, Suren Baghdasaryan wrote: > > > > > On Wed, Jan 12, 2022 at 10:16 AM Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote: > > > > > > > > > > > > On Wed, Jan 12, 2022 at 09:49:00AM -0800, Suren Baghdasaryan wrote: > > > > > > > > This happens with the following config: > > > > > > > > > > > > > > > > CONFIG_CGROUPS=n > > > > > > > > CONFIG_PSI=y > > > > > > > > > > > > > > > > With cgroups disabled these functions are defined as non-static but > > > > > > > > are not defined in the header > > > > > > > > (https://elixir.bootlin.com/linux/latest/source/include/linux/psi.h#L28) > > > > > > > > since the only external user cgroup.c is disabled. The cleanest way to > > > > > > > > fix these I think is by doing smth like this in psi.c: > > > > > > > > > > > > A cleaner way to solve these is simply: > > > > > > > > > > > > #ifndef CONFIG_CGROUPS > > > > > > static struct psi_trigger *psi_trigger_create(...); > > > > > > ... > > > > > > #endif > > > > > > > > > > > > I tested this works: > > > > > > > > > > > > $ cat foo5.c > > > > > > static int psi(void *); > > > > > > > > > > > > int psi(void *x) > > > > > > { > > > > > > return (int)(long)x; > > > > > > } > > > > > > > > > > > > int bar(void *x) > > > > > > { > > > > > > return psi(x); > > > > > > } > > > > > > $ gcc -W -Wall -O2 -c -o foo5.o foo5.c > > > > > > $ readelf -s foo5.o > > > > > > > > > > > > Symbol table '.symtab' contains 4 entries: > > > > > > Num: Value Size Type Bind Vis Ndx Name > > > > > > 0: 0000000000000000 0 NOTYPE LOCAL DEFAULT UND > > > > > > 1: 0000000000000000 0 FILE LOCAL DEFAULT ABS foo5.c > > > > > > 2: 0000000000000000 0 SECTION LOCAL DEFAULT 1 .text > > > > > > 3: 0000000000000000 3 FUNC GLOBAL DEFAULT 1 bar > > > > > > > > > > > > > > > > Thanks Matthew! > > > > > That looks much cleaner. I'll post a separate patch to fix these. My > > > > > main concern was whether it's worth adding more code to satisfy this > > > > > warning but with this approach the code changes are minimal, so I'll > > > > > go ahead and post it shortly. > > > > > > > > Why not simply move the declarations of psi_trigger_create() and > > > > psi_trigger_destroy() in include/linux/psi.h outside of the > > > > '#ifdef CONFIG_CGROUPS' block, to match the .c file? > > > > > > IIRC this was done to avoid another warning that these functions are > > > not used outside of psi.c when CONFIG_CGROUPS=n > > > > > > > What tool gave that warning? > > Let me double-check by building it. It has been a while since I > developed the code and I don't want to mislead by making false claims. > No warnings, so it was probably done to keep the scope of these functions as local as possible. I agree that moving them out of #ifdef CONFIG_CGROUPS in the header file makes sense here. The scope unnecessarily expands when CONFIG_CGROUPS=n but the code is simpler. Will do that then. I noticed there is another warning about psi_cpu_proc_ops and similar structures being unused when CONFIG_PROC_FS=n. Looks like I'll need some more ifdefs to fix all these warnings. > > > > - Eric
