Erich/coreutils - Unnamed repository; edit this file 'description' to name the repository.

Age	Commit message (Collapse)	Author
2015-11-10	tests: ensure programs are built before testing	Pádraig Brady
	programs may not be built due to missing system dependencies, or any program can be excluded at configure time with --enable-no-install-program. So ensure we're not testing the system versions in these cases. * init.cfg (print_ver_): Call require_built_ first. * tests/misc/tty-eof.pl: Skip programs not built. * tests/Coreutils.pm (run_tests): Likewise. * tests/misc/ls-misc.pl: Use 'env test' rather than abs path. * tests/misc/test-diag.pl: Likewise. * tests/local.mk: Adjust include order for dependencies. * tests/misc/arch.sh: Remove redundant calls to require_built_. * tests/misc/chroot-fail.sh: Likewise. * tests/misc/groups-dash.sh: Likewise. * tests/misc/groups-version.sh: Likewise. * tests/misc/stdbuf.sh: Likewise. * tests/cp/acl.sh: Remove problematic call to print_ver_ [gs]etfacl. * tests/mv/acl.sh: Likewise. * cfg.mk (sc_env_test_dependencies): A new syntax check to enforce specifying dependencies with print_ver_ for programs specified through the env command. * du/bigtime.sh: Add new print_ver_ dependencies. * du/max-depth.sh: Likewise. * dd/ascii.sh: Likewise. * tests/ls/capability.sh: Likewise. * tests/ls/root-rel-symlink-color.sh: Likewise. * tests/misc/chroot-fail.sh: Likewise. * tests/misc/readlink-fp-loop.sh: Likewise. * tests/misc/sort-debug-keys.sh: Likewise. * tests/readlink/can-e.sh: Likewise. * tests/readlink/can-f.sh: Likewise. * tests/readlink/can-m.sh: Likewise. * tests/tail-2/inotify-race.sh: Likewise. * tests/tail-2/inotify-race2.sh: Likewise. * tests/touch/no-create-missing.sh: Likewise. * tests/touch/no-dereference.sh: Likewise. * tests/misc/printenv.sh: Tweak to avoid syntax check trigger. * tests/misc/help-version.sh: Likewise. * tests/misc/yes.sh: Likewise. * tests/misc/printf-quote.sh: Use previously unused $prog. * configure.ac (EXTRA_MANS): Add $gl_no_install_prog to the list so that check-x-vs-1 syntax check is satisfied.
2015-03-10	yes: improve efficiency when all args aren't buffered	Giuseppe Scrivano
	* src/yes.c (main): Even when the internal buffer isn't large enough, output what we've buffered already, and interate over the rest. This improves the performance in the edge case where there are many small arguments that overflow the buffer. * tests/misc/yes.sh: Add a test case for the many small arguments case.
2015-03-10	yes: output data more efficiently	Pádraig Brady
	yes(1) may be used to generate repeating patterns of text for test inputs etc., so adjust to be more efficient. Profiling the case where yes(1) is outputting small items through stdio (which was the default case), shows the overhead of continuously processing small items in main() and in stdio: $ yes >/dev/null & perf top -p $! 31.02% yes [.] main 27.36% libc-2.20.so [.] _IO_file_xsputn@@GLIBC_2.2.5 14.51% libc-2.20.so [.] fputs_unlocked 13.50% libc-2.20.so [.] strlen 10.66% libc-2.20.so [.] __GI___mempcpy 1.98% yes [.] fputs_unlocked@plta Sending more data per stdio call improves the situation, but still, there is significant stdio overhead due to memory copies, and the repeated string length checking: $ yes "`echo {1..1000}`" >/dev/null & perf top -p $! 42.26% libc-2.20.so [.] __GI___mempcpy 17.38% libc-2.20.so [.] strlen 5.21% [kernel] [k] __srcu_read_lock 4.58% [kernel] [k] __srcu_read_unlock 4.27% libc-2.20.so [.] _IO_file_xsputn@@GLIBC_2.2.5 2.50% libc-2.20.so [.] __GI___libc_write 2.45% [kernel] [k] system_call 2.40% [kernel] [k] system_call_after_swapgs 2.27% [kernel] [k] vfs_write 2.09% libc-2.20.so [.] _IO_do_write@@GLIBC_2.2.5 2.01% [kernel] [k] fsnotify 1.95% libc-2.20.so [.] _IO_file_write@@GLIBC_2.2.5 1.44% yes [.] main We can avoid all stdio overhead by building up the buffer _once_ and outputting that, and the profile below shows the bottleneck moved to the kernel: $ src/yes >/dev/null & perf top -p $! 15.42% [kernel] [k] __srcu_read_lock 12.98% [kernel] [k] __srcu_read_unlock 9.41% libc-2.20.so [.] __GI___libc_write 9.11% [kernel] [k] vfs_write 8.35% [kernel] [k] fsnotify 8.02% [kernel] [k] system_call 5.84% [kernel] [k] system_call_after_swapgs 4.54% [kernel] [k] __fget_light 3.98% [kernel] [k] sys_write 3.65% [kernel] [k] selinux_file_permission 3.44% [kernel] [k] rw_verify_area 2.94% [kernel] [k] __fsnotify_parent 2.76% [kernel] [k] security_file_permission 2.39% yes [.] main 2.17% [kernel] [k] __fdget_pos 2.13% [kernel] [k] sysret_check 0.81% [kernel] [k] write_null 0.36% yes [.] write@plt Note this change also ensures that yes(1) will only write complete lines for lines shorter than BUFSIZ. * src/yes.c (main): Build up a BUFSIZ buffer of lines, and output that, rather than having stdio process each item. * tests/misc/yes.sh: Add a new test for various buffer sizes. * tests/local.mk: Reference the new test. Fixes http://bugs.gnu.org/20029