![]() The algorithm implements a simple stable topological sort. A quick explanation is somewhat like this: > comment about what you're doing and why. ![]() You should comment each sort routine with a high-level But it also cannot be really shared, without extra parameters,Īs there are 3 slightly different variants of the loop. The code is small enough that this way (static functions) should beīetter. > can inline and you use the same pattern in all places where sorting happens. ![]() > You refactor the sorting code out into a static function that the compiler > At the high-level your patch is almost ready. > (In reply to Paulo Andrade from comment #1) (In reply to Carlos O'Donell from comment #4) This looks really good though and you're making great progress in a difficult part of the dynamic loader. If you can cover those two things, then you're ready to post the patch to libc-alpha for more formal review. When we get a bug report, and we will, we can enlarge the set of automated testing to include the case the bug report claims and see what went wrong. This way we can show that the sorting works for a large set of object dependency orderings. The *best* testing is actually a test which deterministically generates a sequence of permutations of linked objects and verifies they are sorted correctly by the algorithms in question. While it seems unfair, and I understand that, this kind of change has not been undertaken because of the lack of testing. The existing set of tests are insufficient to cover the changes you are proposing. This is particularly important for the weight functions. You should comment each sort routine with a high-level comment about what you're doing and why. You refactor the sorting code out into a static function that the compiler can inline and you use the same pattern in all places where sorting happens. > If there is a loop, the "c" variable in the "sort" function willĪt the high-level your patch is almost ready. > ones that appear first with the lowest weight, that is, less > an entry at most once, by keeping track of, and resetting the weight > This patch implements a simple stable topological sort that moves (In reply to Paulo Andrade from comment #1) The proposed patch runs the test case in 10 ms, and aġ7,45% timedlopen ld-2.17.so do_lookup_xĦ,91% timedlopen ld-2.17.so _dl_map_object_depsĦ,12% timedlopen ld-2.17.so _dl_name_match_pĤ,35% timedlopen ld-2.17.so _dl_sort_finiĤ,33% timedlopen ld-2.17.so dl_open_worker Libreoffice and several other large applications orĮnvironments that load/unload or have large dso dependency Rawhide, and cannot see any problems running kde, gnome, (for basic tests where the problem was detected/reported),Īnd my day to day computers, running rhel-7 and fedora I have been using a patch for some weeks in rhel-6.3 Sample perf output of it taking 8+ secs on a core i5:ģ1,24% timedlopen ld-2.17.so _dl_map_object_depsġ8,36% timedlopen ld-2.17.so _wordcopy_fwd_alignedġ6,50% timedlopen ld-2.17.so _dl_sort_finiġ5,47% timedlopen ld-2.17.so dl_open_workerġ3,08% timedlopen ld-2.17.so _wordcopy_fwd_dest_alignedĠ,07% timedlopen ld-2.17.so do_lookup_x To sort less than 300 shared objects when there a someĬycles. ![]() The loop does not scale well when thereĪre cyclic dependencies, and may take more than 8 seconds Of a very CPU intensive loop in elf/dl-deps.c, elf/dl-fini.cĪnd elf/dl-open.c. Proposed patch v3 updated to master branch as of 27th december 2020Īfter glibc-2.11, there are 3 slightly different instances Simple sh based helper script to run the test caseĭso_deps.c - simple test implementing standalone propose sort and current glibcĭso_3 - Sample input for previous test case, that summarizes the reason of the bug report Sample "redistributable" test case provided by a customer Documentationĭocumentation by Steve Frécinaux. Git-send-bugzilla -n 12345 master Extract all commits which are in the current branch but not in the master branch. Username = " = "********" If you don't specify one of them in the repository configuration nor in the command line, git-send-bugzilla will ask for it before trying to attach the You can specify an URL, an user name and a password for the bugzilla in the repository configuration as follows: If you use this option you shouldn't specify a bug id. Start numbering the patches at instead of 1.ĭon't do anything for real. Send all the selected commits as a single patch. If -n (or bugzilla.numbered in the repository configuration) is specified, instead of " Subject", the first line is formatted as " Attach each commit between and to the bug on GNOME's bugzilla.
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