On 02/04/15 11:05, Karel Zak wrote: > On Tue, Jan 20, 2015 at 02:01:13AM +0000, Pádraig Brady wrote: >> On 30/12/14 22:06, Bernhard Voelker wrote: >>> I just pulled the recent gnulib update, and now the above, expensive >>> test fails: >>> >>> + ulimit -v 40000 >>> + du -sh d >>> du: fts_read failed: d: Cannot allocate memory >>> + fail=1 >>> >>> I guess this due to the inclusion of libmount? >> >> Yes I get the same issue in that test: >> http://git.sv.gnu.org/gitweb/?p=coreutils.git;a=blob;f=tests/rm/many-dir-entries-vs-OOM.sh >> >> Indeed there is significant overhead in using libmount as shown below. >> This is a crazy amount of overhead just to read /proc/self/mountinfo, >> and is the sort of creeping dependencies I hate. The proposed solution >> in the attached gnulib patch, is to require ./configure --with-libmount >> to enable this feature. I.E. it's disabled by default. >> >> cheers, >> Pádraig >> >> ======= without ========= >> $ (ulimit -v 5380; du -s .) >> >> $ ldd /usr/bin/du >> linux-vdso.so.1 => (0x00007fff0d7fe000) >> libc.so.6 => /lib64/libc.so.6 (0x00007fd414a32000) >> /lib64/ld-linux-x86-64.so.2 (0x00007fd414e0b000) >> >> $ time du -s src/du.c >/dev/null >> real 0m0.003s >> user 0m0.000s >> sys 0m0.003s >> >> ======= with ========= >> $ (ulimit -v 23250; src/du -s .) >> >> $ ldd src/du >> linux-vdso.so.1 => (0x00007fff76ca8000) >> libc.so.6 => /lib64/libc.so.6 (0x00007f2a1f742000) >> /lib64/ld-linux-x86-64.so.2 (0x00007f2a1fd61000) >> libmount.so.1 => /lib64/libmount.so.1 (0x00007f2a1faff000) >> libblkid.so.1 => /lib64/libblkid.so.1 (0x00007f2a1f501000) >> libuuid.so.1 => /lib64/libuuid.so.1 (0x00007f2a1f2fc000) >> libselinux.so.1 => /lib64/libselinux.so.1 (0x00007f2a1f0d7000) >> libpcre.so.1 => /lib64/libpcre.so.1 (0x00007f2a1ee69000) >> liblzma.so.5 => /lib64/liblzma.so.5 (0x00007f2a1ec44000) >> libdl.so.2 => /lib64/libdl.so.2 (0x00007f2a1ea40000) >> libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f2a1e823000) > > The problem is libselinux, but on selinux based system you have all the > libraries already in memory for many another tools... Indeed. I see libmount links with libselinux to use selinux_trans_to_raw_context() for the context= mount options etc. I suppose one could split libmount to avoid that dependency, though it's probably not worth it for this case at least? I still think it's worth avoiding the dependencies here though with the little extra code. I'll add a comment to the patch about libselinux as the source of these deps. thanks! Pádraig -- To unsubscribe from this list: send the line "unsubscribe util-linux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
