> On Nov 11, 2015, at 7:56 PM, Maxim Kuvyrkov <maxim.kuvyr...@linaro.org> wrote: > > Hi, > > This patch fixes an obscure cross-testing problem that crashed (OOMed) our > boards at Linaro. Several tests in libstdc++ (e.g., [1]) limit themselves to > some reasonable amount of RAM and then try to allocate 32 gigs. > Unfortunately, the configure test that checks presence of setrlimit is rather > strange: if target is native, then try compile file with call to setrlimit -- > if compilation succeeds, then use setrlimit, otherwise, ignore setrlimit. > The strange part is that the compilation check is done only for native > targets, as if cross-toolchains can't generate working executables. [This is > rather odd, and I might be missing some underlaying caveat.] > > Therefore, when testing a cross toolchain, the test [1] still tries to > allocate 32GB of RAM with no setrlimit restrictions. On most targets that > people use for cross-testing this is not an issue because either > - the target is 32-bit, so there is no 32GB user-space to speak of, or > - the target board has small amount of RAM and no swap, so allocation > immediately fails, or > - the target board has plenty of RAM, so allocating 32GB is not an issue. > > However, if one is testing on a 64-bit board with 16GB or RAM and 16GB of > swap, then one gets into an obscure near-OOM swapping condition. This is > exactly the case with cross-testing aarch64-linux-gnu toolchains on APM > Mustang. > > The attached patch removes "native" restriction from configure test for > setrlimit. This enables setrlimit restrictions on the testsuite, and the > test [1] expectedly fails to allocate 32GB due to setrlimit restriction. > > I have tested it on x86_64-linux-gnu and i686-linux-gnu native toolchains, > and aarch64-linux-gnu and arm-linux-gnueabi[hf] cross-toolchains with no > regressions [*]. > > OK to commit? > > I didn't go as far as enabling setenv/locale tests when cross-testing > libstdc++ because I remember of issues with generating locales in cross-built > glibc. In any case, locale tests are unlikely to OOM the test board the way > that absence of setrlimit does. > > [1] 27_io/ios_base/storage/2.cc > > [*] Cross-testing using user-mode QEMU made 27_io/fpos/14775.cc execution > test to FAIL. This test uses setrlimit set max file size, and is misbehaving > only under QEMU. I believe this a QEMU issue with not handling setrlimit > correctly. >
Ping. -- Maxim Kuvyrkov www.linaro.org
