Em Fri, Jul 19, 2019 at 10:54:44AM -0700, Andrii Nakryiko escreveu: > On Thu, Jul 18, 2019 at 6:16 PM Arnaldo Carvalho de Melo > <arnaldo.melo@xxxxxxxxx> wrote: > > > > Em Thu, Jul 18, 2019 at 02:16:29PM -0700, Andrii Nakryiko escreveu: > > > On Thu, Jul 18, 2019 at 12:14 PM Arnaldo Carvalho de Melo > > > <arnaldo.melo@xxxxxxxxx> wrote: > > > > > > > > Em Thu, Jul 18, 2019 at 03:56:19PM -0300, Arnaldo Carvalho de Melo escreveu: > > > > > I'll stop and replace my patch with yours to see if it survives all the > > > > > test builds... > > > > > > > > So, Alpine:3.4, the first image for this distro I did when I started > > > > these builds, survives the 6 builds with gcc and clang with your patch: > > > > > > > > > > > > [perfbuilder@quaco linux-perf-tools-build]$ export PERF_TARBALL=http://192.168.124.1/perf/perf-5.2.0.tar.xz > > > > [perfbuilder@quaco linux-perf-tools-build]$ dm > > > > 1 alpine:3.4 : Ok gcc (Alpine 5.3.0) 5.3.0, clang version 3.8.0 (tags/RELEASE_380/final) > > > > > > > > > > > > [perfbuilder@quaco linux-perf-tools-build]$ grep "+ make" dm.log/alpine\:3.4 > > > > + make ARCH= CROSS_COMPILE= EXTRA_CFLAGS= -C /git/linux/tools/perf O=/tmp/build/perf > > > > + make ARCH= CROSS_COMPILE= EXTRA_CFLAGS= NO_LIBELF=1 -C /git/linux/tools/perf O=/tmp/build/perf > > > > + make ARCH= CROSS_COMPILE= EXTRA_CFLAGS= -C /git/linux/tools/perf O=/tmp/build/perf CC=clang > > > > + make ARCH= CROSS_COMPILE= EXTRA_CFLAGS= NO_LIBELF=1 -C /git/linux/tools/perf O=/tmp/build/perf CC=clang > > > > + make ARCH= CROSS_COMPILE= EXTRA_CFLAGS= LIBCLANGLLVM=1 -C /git/linux/tools/perf O=/tmp/build/perf CC=clang > > > > + make ARCH= CROSS_COMPILE= EXTRA_CFLAGS= LIBCLANGLLVM=1 -C /git/linux/tools/perf O=/tmp/build/perf > > > > [perfbuilder@quaco linux-perf-tools-build]$ > > > > > > > > Probably all the rest will go well, will let you know. > > > > > > > > Daniel, do you mind if I carry this one in my perf/core branch? Its > > > > small and shouldn't clash with other patches, I think. It should go > > > > upstream soon: > > > > > > > > Andrii, there are these others: > > > > > > I took a look at them, but I think it would be better, if you could > > > post them as proper patches to > > > bpf@xxxxxxxxxxxxxxx/netdev@xxxxxxxxxxxxxxx, so that others can check > > > and comment, if necessary. > > > > > > One nit for all three of them: we typically prefix subject with just > > > "libbpf: " instead of "tools lib libbpf". > > > > Sure, that was mechanic, I do it like that for the patches I upstream, > > and that was like that in the beginning: > > > > [acme@quaco perf]$ git log --oneline tools/lib/bpf | grep lib | tail > > 9d759a9b4ac2 tools lib bpf: Collect map definition in bpf_object > > d8ad6a15cc3a tools lib bpf: Don't do a feature check when cleaning > > 6371ca3b541c bpf tools: Improve libbpf error reporting > > 0c77c04aa9c2 tools lib bpf: Change FEATURE-DUMP to FEATURE-DUMP.libbpf > > 715f8db9102f tools lib bpf: Fix compiler warning on CentOS 6 > > 7c422f557266 tools build: Build fixdep helper from perf and basic libs > > 65f041bee783 tools lib bpf: Use FEATURE_USER to allow building in the same dir as perf > > 20517cd9c593 tools lib bpf: Fix up FEATURE_{TESTS,DISPLAY} usage > > cc4228d57c4c bpf tools: Check endianness and make libbpf fail early > > 1b76c13e4b36 bpf tools: Introduce 'bpf' library and add bpf feature check > > [acme@quaco perf]$ > > > > Anyway, I'll resubmit the patches that you acked to bpf@vger and will > > let my container tests fail for those cases, sticking a warning so that > > Ingo knows that this is being dealt with and those problems will get > > fixed soon when the bpf tree merges upstream. > > Great, thanks! > > > > > > > > > > > 8dfb6ed300bf tools lib bpf: Avoid designated initializers for unnamed union members > > > > > > + attr.sample_period = attr.wakeup_events = 1; > > > > > > let's instead > > > > > > + attr.sample_period = 1; > > > + attr.wakeup_events = 1; > > > > > > I don't like multi-assignments. > > > > Meh, what's wrong with it? :) > > Nothing, objectively :) But I don't remember seeing multi-assignments > in libbpf code base, so nitpicking for consistency's sake.... > > > > > > > Also, if we are doing explicit assignment, let's do it for all the > > > fields, not split initialization like that. > > > > If that is what takes to get it to build everywhere, no problem. In > > tools/perf I'm used to doing it, documents that this is an oddity to > > support more systems :) > > > > > > 80f7f8f21441 tools lib bpf: Avoid using 'link' as it shadows a global definition in some systems > > > > > > For this one I'm confused. What compiler/system you are getting it on? > > > > > I tried to reproduce it with this example (trying both global > > > variable, as well as function): > > > > > > #include <stdio.h> > > > > > > //int link = 1; > > > void link() {} > > > > > > int f(int link) { > > > return link; > > > } > > > int main() { > > > printf("%d\n", f(123)); > > > return 0; > > > } > > > > > > I haven't gotten any errors nor warnings. I'm certainly liking > > > existing naming better, but my main concern is that we'll probably add > > > more code like this, and we'll forget about this problem and will > > > re-introduce. > > > > yeah, this happens from time to time with centos:6 and IIRC > > amazonlinux:1, oraclelinux:6. > > > > I still remember when I got reports from the twitter guys when something > > broke on rhel:5, that was the main reason to get these container tests > > in place, you never know where people are using this, and since before > > upstreaming I do the tests, fixing those became second nature 8-) > > > > > So I'd rather figure out why it's happening and some rare system and > > > see if we can mitigate that without all the renames. > > Ok, did some more googling. This warning (turned error in your setup) > is emitted when -Wshadow option is enabled for GCC/clang. It appears > to be disabled by default, so it must be enabled somewhere for perf > build or something. Right, I came to the exact same conclusion, doing tests here: [perfbuilder@3a58896a648d tmp]$ gcc -Wshadow shadow_global_decl.c -o shadow_global_decl shadow_global_decl.c: In function 'main': shadow_global_decl.c:9: warning: declaration of 'link' shadows a global declaration shadow_global_decl.c:4: warning: shadowed declaration is here [perfbuilder@3a58896a648d tmp]$ gcc --version |& head -1 gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-23) [perfbuilder@3a58896a648d tmp]$ gcc shadow_global_decl.c -o shadow_global_decl [perfbuilder@3a58896a648d tmp]$ So I'm going to remove this warning from the places where it causes problems. > Would it be possible to disable it at least for libbpf when building > from perf either everywhere or for those systems where you see this > warning? I don't think this warning is useful, to be honest, just > random name conflict between any local and global variables will cause > this. Yeah, I might end up having this applied. [acme@quaco perf]$ git diff diff --git a/tools/scripts/Makefile.include b/tools/scripts/Makefile.include index 495066bafbe3..b6e902a2312f 100644 --- a/tools/scripts/Makefile.include +++ b/tools/scripts/Makefile.include @@ -32,7 +32,6 @@ EXTRA_WARNINGS += -Wno-system-headers EXTRA_WARNINGS += -Wold-style-definition EXTRA_WARNINGS += -Wpacked EXTRA_WARNINGS += -Wredundant-decls -EXTRA_WARNINGS += -Wshadow EXTRA_WARNINGS += -Wstrict-prototypes EXTRA_WARNINGS += -Wswitch-default EXTRA_WARNINGS += -Wswitch-enum [acme@quaco perf]$ Sorry for the noise... - Arnaldo
