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* Merge branch 'en/remerge-diff'Junio C Hamano2022-02-161-5/+50
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | "git log --remerge-diff" shows the difference from mechanical merge result and the result that is actually recorded in a merge commit. * en/remerge-diff: diff-merges: avoid history simplifications when diffing merges merge-ort: mark conflict/warning messages from inner merges as omittable show, log: include conflict/warning messages in --remerge-diff headers diff: add ability to insert additional headers for paths merge-ort: format messages slightly different for use in headers merge-ort: mark a few more conflict messages as omittable merge-ort: capture and print ll-merge warnings in our preferred fashion ll-merge: make callers responsible for showing warnings log: clean unneeded objects during `log --remerge-diff` show, log: provide a --remerge-diff capability
| * merge-ort: mark conflict/warning messages from inner merges as omittableElijah Newren2022-02-021-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | A recursive merge involves merging the merge bases of the two branches being merged. Such an inner merge can itself generate conflict notices. While such notices may be useful when initially trying to create a merge, they seem to just be noise when investigating merges later with --remerge-diff. (Especially when both sides of the outer merge resolved the conflict the same way leading to no overall conflict.) Remove them. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * show, log: include conflict/warning messages in --remerge-diff headersElijah Newren2022-02-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | Conflicts such as modify/delete, rename/rename, or file/directory are not representable via content conflict markers, and the normal output messages notifying users about these were dropped with --remerge-diff. While we don't want these messages randomly shown before the commit and diff headers, we do want them to still be shown; include them as part of the diff headers instead. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * merge-ort: format messages slightly different for use in headersElijah Newren2022-02-021-2/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When users run git show --remerge-diff $MERGE_COMMIT or git log -p --remerge-diff ... stdout is not an appropriate location to dump conflict messages, but we do want to provide them to users. We will include them in the diff headers instead...but for that to work, we need for any multiline messages to replace newlines with both a newline and a space. Add a new flag to signal when we want these messages modified in such a fashion, and use it in path_msg() to modify these messages this way. Also, allow a special prefix to be specified for these headers. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * merge-ort: mark a few more conflict messages as omittableElijah Newren2022-02-021-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | path_msg() has the ability to mark messages as omittable, designed for remerge-diff where we'll instead be showing conflict messages as diff headers for a subsequent diff. While all these messages are very useful when trying to create a merge initially, early use with the --remerge-diff feature (the only user of this omittable conflict message capability), suggests that the particular messages marked in this commit are just noise when trying to see what changes users made to create a merge commit. Mark them as omittable. Note that there were already a few messages marked as omittable in merge-ort when doing a remerge-diff, because the development of --remerge-diff preceded the upstreaming of merge-ort and I was trying to ensure merge-ort could handle all the necessary requirements. See commit c5a6f65527 ("merge-ort: add modify/delete handling and delayed output processing", 2020-12-03) for the initial details. For some examples of already-marked-as-omittable messages, see either "Auto-merging <path>" or some of the submodule update hints. This commit just adds two more messages that should also be omittable. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * merge-ort: capture and print ll-merge warnings in our preferred fashionElijah Newren2022-02-021-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of immediately printing ll-merge warnings to stderr, we save them in our output strbuf. Besides allowing us to move these warnings to a special file for --remerge-diff, this has two other benefits for regular merges done by merge-ort: * The deferral of messages ensures we can print all messages about any given path together (merge-recursive was known to sometimes intersperse messages about other paths, particularly when renames were involved). * The deferral of messages means we can avoid printing spurious conflict messages when we just end up aborting due to local user modifications in the way. (In contrast to merge-recursive.c which prematurely checks for local modifications in the way via unpack_trees() and gets the check wrong both in terms of false positives and false negatives relative to renames, merge-ort does not perform the local modifications in the way check until the checkout() step after the full merge has been computed.) Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * ll-merge: make callers responsible for showing warningsElijah Newren2022-02-021-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since some callers may want to send warning messages to somewhere other than stdout/stderr, stop printing "warning: Cannot merge binary files" from ll-merge and instead modify the return status of ll_merge() to indicate when a merge of binary files has occurred. Message printing probably does not belong in a "low-level merge" anyway. This commit continues printing the message as-is, just from the callers instead of within ll_merge(). Future changes will start handling the message differently in the merge-ort codepath. There was one special case here: the callers in rerere.c do NOT check for and print such a message; since those code paths explicitly skip over binary files, there is no reason to check for a return status of LL_MERGE_BINARY_CONFLICT or print the related message. Note that my methodology included first modifying ll_merge() to return a struct, so that the compiler would catch all the callers for me and ensure I had modified all of them. After modifying all of them, I then changed the struct to an enum. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
* | Merge branch 'en/plug-leaks-in-merge'Junio C Hamano2022-02-091-5/+5
|\ \ | | | | | | | | | | | | | | | | | | | | | Leakfix. * en/plug-leaks-in-merge: merge: fix memory leaks in cmd_merge() merge-ort: fix memory leak in merge_ort_internal()
| * | merge-ort: fix memory leak in merge_ort_internal()Elijah Newren2022-01-211-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The documentation for merge_incore_recursive(), modelled after merge_recursive(), notes that merge_bases will be consumed (emptied) so make a copy if you need it However, in merge_ort_internal() (which merge_incore_recursive() calls), it runs merged_merge_bases = pop_commit(&merge_bases); ... for (iter = merge_bases; iter; iter = iter->next) { ... } In other words, it only consumes the *first* entry of merge_bases, and the rest it iterates through. If it iterated through all of them, the caller could be responsible for free'ing the memory. If it consumed all of them, the current documentation would be correct and the callers would need to do nothing. The current middle ground makes it impossible for callers to avoid memory leaks, since any attempt to use the merge_bases it passes in would result in a use-after-free. It turns out this part of the code was copied from merge-recursive.c, which has had the same bug for 15.5 years. However, since we are trying to keep merge-recursive.c stable as we sunset it, let's just fix the leak in in merge_ort_internal() by having it actually consume all the elements of the merge_bases commit_list. Testing this commit against t6404 (the first testcase specifically about recursive merges) under valgrind shows that this patch fixes the following leak: 32 (16 direct, 16 indirect) bytes in 1 blocks are definitely lost \ in loss record 49 of 126 at 0x484086F: malloc (vg_replace_malloc.c:380) by 0x69FFEB: do_xmalloc (wrapper.c:41) by 0x6A0073: xmalloc (wrapper.c:62) by 0x52A72D: commit_list_insert (commit.c:556) by 0x47EC86: try_merge_strategy (merge.c:751) by 0x48143B: cmd_merge (merge.c:1679) by 0x40686E: run_builtin (git.c:464) by 0x406C51: handle_builtin (git.c:716) by 0x406E96: run_argv (git.c:783) by 0x40730A: cmd_main (git.c:914) by 0x4E7DFA: main (common-main.c:56) Reported-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
* | | Merge branch 'en/merge-ort-restart-optim-fix'Junio C Hamano2022-02-091-0/+4
|\ \ \ | |/ / |/| | | | | | | | | | | | | | | | | The merge-ort misbehaved when merge.renameLimit configuration is set too low and failed to find all renames. * en/merge-ort-restart-optim-fix: merge-ort: avoid assuming all renames detected
| * | merge-ort: avoid assuming all renames detectedElijah Newren2022-01-171-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In commit 8b09a900a1 ("merge-ort: restart merge with cached renames to reduce process entry cost", 2021-07-16), we noted that in the merge-ort steps of collect_merge_info() detect_and_process_renames() process_entries() that process_entries() was expensive, and we could often make it cheaper by changing this to collect_merge_info() detect_and_process_renames() <cache all the renames, and restart> collect_merge_info() detect_and_process_renames() process_entries() because the second collect_merge_info() would be cheaper (we could avoid traversing into some directories), the second detect_and_process_renames() would be free since we had already detected all renames, and then process_entries() has far fewer entries to handle. However, this was built on the assumption that the first detect_and_process_renames() actually detected all potential renames. If someone has merge.renameLimit set to some small value, that assumption is violated which manifests later with the following message: $ git -c merge.renameLimit=1 rebase upstream ... git: merge-ort.c:546: clear_or_reinit_internal_opts: Assertion `renames->cached_pairs_valid_side == 0' failed. Turn off this cache-renames-and-restart whenever we cannot detect all renames, and add a testcase that would have caught this problem. Reported-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Elijah Newren <newren@gmail.com> Tested-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
* | | merge-ort: fix bug with renormalization and rename/delete conflictsElijah Newren2021-12-301-3/+16
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Ever since commit a492d5331c ("merge-ort: ensure we consult df_conflict and path_conflicts", 2021-06-30), when renormalization is active AND a file is involved in a rename/delete conflict BUT the file is unmodified (either before or after renormalization), merge-ort was running into an assertion failure. Prior to that commit (or if assertions were compiled out), merge-ort would mis-merge instead, ignoring the rename/delete conflict and just deleting the file. Remove the assertions, fix the code appropriately, leave some good comments in the code, and add a testcase for this situation. Reported-by: Ralf Thielow <ralf.thielow@gmail.com> Signed-off-by: Elijah Newren <newren@gmail.com> Reviewed-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
* | Merge branch 'jt/no-abuse-alternate-odb-for-submodules'Junio C Hamano2021-10-251-14/+4
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Follow through the work to use the repo interface to access submodule objects in-process, instead of abusing the alternate object database interface. * jt/no-abuse-alternate-odb-for-submodules: submodule: trace adding submodule ODB as alternate submodule: pass repo to check_has_commit() object-file: only register submodule ODB if needed merge-{ort,recursive}: remove add_submodule_odb() refs: peeling non-the_repository iterators is BUG refs: teach arbitrary repo support to iterators refs: plumb repo into ref stores
| * | merge-{ort,recursive}: remove add_submodule_odb()Jonathan Tan2021-10-081-14/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After the parent commit and some of its ancestors, the only place commits are being accessed through alternates is in the user-facing message formatting code. Fix those, and remove the add_submodule_odb() calls. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | Merge branch 'jt/add-submodule-odb-clean-up' into ↵Junio C Hamano2021-09-221-18/+35
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | jt/no-abuse-alternate-odb-for-submodules * jt/add-submodule-odb-clean-up: revision: remove "submodule" from opt struct repository: support unabsorbed in repo_submodule_init submodule: remove unnecessary unabsorbed fallback
* | \ \ Merge branch 'en/removing-untracked-fixes'Junio C Hamano2021-10-131-7/+1
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Various fixes in code paths that move untracked files away to make room. * en/removing-untracked-fixes: Documentation: call out commands that nuke untracked files/directories Comment important codepaths regarding nuking untracked files/dirs unpack-trees: avoid nuking untracked dir in way of locally deleted file unpack-trees: avoid nuking untracked dir in way of unmerged file Change unpack_trees' 'reset' flag into an enum Remove ignored files by default when they are in the way unpack-trees: make dir an internal-only struct unpack-trees: introduce preserve_ignored to unpack_trees_options read-tree, merge-recursive: overwrite ignored files by default checkout, read-tree: fix leak of unpack_trees_options.dir t2500: add various tests for nuking untracked files
| * | | | Remove ignored files by default when they are in the wayElijah Newren2021-09-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change several commands to remove ignored files by default when they are in the way. Since some commands (checkout, merge) take a --no-overwrite-ignore option to allow the user to configure this, and it may make sense to add that option to more commands (and in the case of merge, actually plumb that configuration option through to more of the backends than just the fast-forwarding special case), add little comments about where such flags would be used. Incidentally, this fixes a test failure in t7112. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | | | unpack-trees: introduce preserve_ignored to unpack_trees_optionsElijah Newren2021-09-271-7/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, every caller of unpack_trees() that wants to ensure ignored files are overwritten by default needs to: * allocate unpack_trees_options.dir * flip the DIR_SHOW_IGNORED flag in unpack_trees_options.dir->flags * call setup_standard_excludes AND then after the call to unpack_trees() needs to * call dir_clear() * deallocate unpack_trees_options.dir That's a fair amount of boilerplate, and every caller uses identical code. Make this easier by instead introducing a new boolean value where the default value (0) does what we want so that new callers of unpack_trees() automatically get the appropriate behavior. And move all the handling of unpack_trees_options.dir into unpack_trees() itself. While preserve_ignored = 0 is the behavior we feel is the appropriate default, we defer fixing commands to use the appropriate default until a later commit. So, this commit introduces several locations where we manually set preserve_ignored=1. This makes it clear where code paths were previously preserving ignored files when they should not have been; a future commit will flip these to instead use a value of 0 to get the behavior we want. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
* | | | | Merge branch 'jt/add-submodule-odb-clean-up'Junio C Hamano2021-10-061-18/+35
|\ \ \ \ \ | | |_|/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | More code paths that use the hack to add submodule's object database to the set of alternate object store have been cleaned up. * jt/add-submodule-odb-clean-up: revision: remove "submodule" from opt struct repository: support unabsorbed in repo_submodule_init submodule: remove unnecessary unabsorbed fallback
| * | | | revision: remove "submodule" from opt structJonathan Tan2021-09-091-18/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Clean up a TODO in revision.h by removing the "submodule" field from struct setup_revision_opt. This field is only used to specify the ref store to use, so use rev_info->repo to determine the ref store instead. The only users of this field are merge-ort.c and merge-recursive.c. However, both these files specify the superproject as rev_info->repo and the submodule as setup_revision_opt->submodule. In order to be able to pass the submodule as rev_info->repo, all commits must be parsed with the submodule explicitly specified; this patch does that as well. (An incremental solution in which only some commits are parsed with explicit submodule will not work, because if the same commit is parsed twice in different repositories, there will be 2 heap-allocated object structs corresponding to that commit, and any flag set by the revision walking mechanism on one of them will not be reflected onto the other.) Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
* | | | | Merge branch 'en/typofixes'Junio C Hamano2021-09-281-1/+1
|\ \ \ \ \ | |_|_|/ / |/| | | / | | |_|/ | |/| | | | | | | | | | | | | | Typofixes. * en/typofixes: merge-ort: fix completely wrong comment trace2.h: fix trivial comment typo
| * | | merge-ort: fix completely wrong commentElijah Newren2021-09-201-1/+1
| |/ / | | | | | | | | | | | | | | | | | | | | | Not sure what happened, but the comment is describing code elsewhere in the file. Fix the comment to actually discuss the code that follows. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
* | | Merge branch 'ds/mergies-with-sparse-index'Junio C Hamano2021-09-201-0/+15
|\ \ \ | |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Various mergy operations have been prepared to work efficiently with the sparse index. * ds/mergies-with-sparse-index: sparse-index: integrate with cherry-pick and rebase sequencer: ensure full index if not ORT strategy t1092: add cherry-pick, rebase tests merge-ort: expand only for out-of-cone conflicts merge: make sparse-aware with ORT diff: ignore sparse paths in diffstat
| * | merge-ort: expand only for out-of-cone conflictsDerrick Stolee2021-09-091-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge conflicts happen often enough to want to avoid expanding a sparse index when they happen, as long as those conflicts are within the sparse-checkout cone. If a conflict exists outside of the sparse-checkout cone, then we still need to expand before iterating over the index entries. This is critical to do in advance because of how the original_cache_nr is tracked to allow inserting and replacing cache entries. Iterate over the conflicted files and check if any paths are outside of the sparse-checkout cone. If so, then expand the full index. Add a test that demonstrates that we do not expand the index, even when we hit a conflict within the sparse-checkout cone. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * | merge: make sparse-aware with ORTDerrick Stolee2021-09-091-0/+8
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow 'git merge' to operate without expanding a sparse index, at least not immediately. The index still will be expanded in a few cases: 1. If the merge strategy is 'recursive', then we enable command_requires_full_index at the start of the merge_recursive() method. We expect sparse-index users to also have the 'ort' strategy enabled. 2. With the 'ort' strategy, if the merge results in a conflicted file, then we expand the index before updating the working tree. The loop that iterates over the worktree replaces index entries and tracks 'origintal_cache_nr' which can become completely wrong if the index expands in the middle of the operation. This safety valve is important before that loop starts. A later change will focus this to only expand if we indeed have a conflict outside of the sparse-checkout cone. 3. Other merge strategies are executed as a 'git merge-X' subcommand, and those strategies are currently protected with the 'command_requires_full_index' guard. Some test updates are required, including a mistaken 'git checkout -b' that did not specify the base branch, causing merges to be fast-forward merges. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
* | Merge branch 'en/ort-perf-batch-15'Junio C Hamano2021-08-241-85/+103
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | Final batch for "merge -sort" optimization. * en/ort-perf-batch-15: merge-ort: remove compile-time ability to turn off usage of memory pools merge-ort: reuse path strings in pool_alloc_filespec merge-ort: store filepairs and filespecs in our mem_pool diffcore-rename, merge-ort: add wrapper functions for filepair alloc/dealloc merge-ort: switch our strmaps over to using memory pools merge-ort: set up a memory pool merge-ort: add pool_alloc, pool_calloc, and pool_strndup wrappers diffcore-rename: use a mem_pool for exact rename detection's hashmap merge-ort: rename str{map,intmap,set}_func()
| * merge-ort: remove compile-time ability to turn off usage of memory poolsElijah Newren2021-08-031-162/+47
| | | | | | | | | | | | | | | | | | | | | | | | Simplify code maintenance by removing the ability to toggle between usage of memory pools and direct allocations. This allows us to also remove paths_to_free since it was solely about bookkeeping to make sure we freed the necessary paths, and allows us to remove some auxiliary functions. Suggested-by: Jeff King <peff@peff.net> Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * merge-ort: reuse path strings in pool_alloc_filespecElijah Newren2021-07-301-7/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pool_alloc_filespec() was written so that the code when pool != NULL mimicked the code from alloc_filespec(), which including allocating enough extra space for the path and then copying it. However, the path passed to pool_alloc_filespec() is always going to already be in the same memory pool, so we may as well reuse it instead of copying it. For the testcases mentioned in commit 557ac0350d ("merge-ort: begin performance work; instrument with trace2_region_* calls", 2020-10-28), this change improves the performance as follows: Before After no-renames: 198.5 ms ± 3.4 ms 198.3 ms ± 2.9 ms mega-renames: 679.1 ms ± 5.6 ms 661.8 ms ± 5.9 ms just-one-mega: 271.9 ms ± 2.8 ms 264.6 ms ± 2.5 ms Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * merge-ort: store filepairs and filespecs in our mem_poolElijah Newren2021-07-301-12/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | For the testcases mentioned in commit 557ac0350d ("merge-ort: begin performance work; instrument with trace2_region_* calls", 2020-10-28), this change improves the performance as follows: Before After no-renames: 198.1 ms ± 2.6 ms 198.5 ms ± 3.4 ms mega-renames: 715.8 ms ± 4.0 ms 679.1 ms ± 5.6 ms just-one-mega: 276.8 ms ± 4.2 ms 271.9 ms ± 2.8 ms Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * diffcore-rename, merge-ort: add wrapper functions for filepair alloc/deallocElijah Newren2021-07-301-0/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | We want to be able to allocate filespecs and filepairs using a mem_pool. However, filespec data will still remain outside the pool (perhaps in the future we could plumb the pool through the various diff APIs to allocate the filespec data too, but for now we are limiting the scope). Add some extra functions to allocate these appropriately based on the non-NULL-ness of opt->priv->pool, as well as some extra functions to handle correctly deallocating the relevant parts of them. A future commit will make use of these new functions. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * merge-ort: switch our strmaps over to using memory poolsElijah Newren2021-07-301-50/+75
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For all the strmaps (including strintmaps and strsets) whose memory is unconditionally freed as part of clear_or_reinit_internal_opts(), switch them over to using our new memory pool. For the testcases mentioned in commit 557ac0350d ("merge-ort: begin performance work; instrument with trace2_region_* calls", 2020-10-28), this change improves the performance as follows: Before After no-renames: 202.5 ms ± 3.2 ms 198.1 ms ± 2.6 ms mega-renames: 1.072 s ± 0.012 s 715.8 ms ± 4.0 ms just-one-mega: 357.3 ms ± 3.9 ms 276.8 ms ± 4.2 ms Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * merge-ort: set up a memory poolElijah Newren2021-07-301-0/+25
| | | | | | | | | | | | | | | | | | | | merge-ort has a lot of data structures, and they all tend to be freed together in clear_or_reinit_internal_opts(). Set up a memory pool to allow us to make these allocations and deallocations faster. Future commits will adjust various callers to make use of this memory pool. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * merge-ort: add pool_alloc, pool_calloc, and pool_strndup wrappersElijah Newren2021-07-301-0/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make the code more flexible so that it can handle both being run with or without a memory pool by adding utility functions which will either call xmalloc, xcalloc, xstrndup or mem_pool_alloc, mem_pool_calloc, mem_pool_strndup depending on whether we have a non-NULL memory pool. A subsequent commit will make use of these. (We will actually be dropping these functions soon and just assuming we always have a memory pool, but the flexibility was very useful during development of merge-ort so I want to be able to restore it if needed.) Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * merge-ort: rename str{map,intmap,set}_func()Elijah Newren2021-07-301-13/+13
| | | | | | | | | | | | | | | | | | In order to make it clearer that these three variables holding a function refer to functions that will clear the strmap/strintmap/strset, rename them to str{map,intmap,set}_clear_func(). Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
* | Merge branch 'en/ort-perf-batch-14'Junio C Hamano2021-08-041-11/+388
|\ \ | |/ | | | | | | | | | | | | | | | | | | | | | | Further optimization on "merge -sort" backend. * en/ort-perf-batch-14: merge-ort: restart merge with cached renames to reduce process entry cost merge-ort: avoid recursing into directories when we don't need to merge-ort: defer recursing into directories when merge base is matched merge-ort: add a handle_deferred_entries() helper function merge-ort: add data structures for allowable trivial directory resolves merge-ort: add some more explanations in collect_merge_info_callback() merge-ort: resolve paths early when we have sufficient information
| * merge-ort: restart merge with cached renames to reduce process entry costElijah Newren2021-07-201-6/+86
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The merge algorithm mostly consists of the following three functions: collect_merge_info() detect_and_process_renames() process_entries() Prior to the trivial directory resolution optimization of the last half dozen commits, process_entries() was consistently the slowest, followed by collect_merge_info(), then detect_and_process_renames(). When the trivial directory resolution applies, it often dramatically decreases the amount of time spent in the two slower functions. Looking at the performance results in the previous commit, the trivial directory resolution optimization helps amazingly well when there are no relevant renames. It also helps really well when reapplying a long series of linear commits (such as in a rebase or cherry-pick), since the relevant renames may well be cached from the first reapplied commit. But when there are any relevant renames that are not cached (represented by the just-one-mega testcase), then the optimization does not help at all. Often, I noticed that when the optimization does not apply, it is because there are a handful of relevant sources -- maybe even only one. It felt frustrating to need to recurse into potentially hundreds or even thousands of directories just for a single rename, but it was needed for correctness. However, staring at this list of functions and noticing that process_entries() is the most expensive and knowing I could avoid it if I had cached renames suggested a simple idea: change collect_merge_info() detect_and_process_renames() process_entries() into collect_merge_info() detect_and_process_renames() <cache all the renames, and restart> collect_merge_info() detect_and_process_renames() process_entries() This may seem odd and look like more work. However, note that although we run collect_merge_info() twice, the second time we get to employ trivial directory resolves, which makes it much faster, so the increased time in collect_merge_info() is small. While we run detect_and_process_renames() again, all renames are cached so it's nearly a no-op (we don't call into diffcore_rename_extended() but we do have a little bit of data structure checking and fixing up). And the big payoff comes from the fact that process_entries(), will be much faster due to having far fewer entries to process. This restarting only makes sense if we can save recursing into enough directories to make it worth our while. Introduce a simple heuristic to guide this. Note that this heuristic uses a "wanted_factor" that I have virtually no actual real world data for, just some back-of-the-envelope quasi-scientific calculations that I included in some comments and then plucked a simple round number out of thin air. It could be that tweaking this number to make it either higher or lower improves the optimization. (There's slightly more here; when I first introduced this optimization, I used a factor of 10, because I was completely confident it was big enough to not cause slowdowns in special cases. I was certain it was higher than needed. Several months later, I added the rough calculations which make me think the optimal number is close to 2; but instead of pushing to the limit, I just bumped it to 3 to reduce the risk that there are special cases where this optimization can result in slowing down the code a little. If the ratio of path counts is below 3, we probably will only see minor performance improvements at best anyway.) Also, note that while the diffstat looks kind of long (nearly 100 lines), more than half of it is in two comments explaining how things work. For the testcases mentioned in commit 557ac0350d ("merge-ort: begin performance work; instrument with trace2_region_* calls", 2020-10-28), this change improves the performance as follows: Before After no-renames: 205.1 ms ± 3.8 ms 204.2 ms ± 3.0 ms mega-renames: 1.564 s ± 0.010 s 1.076 s ± 0.015 s just-one-mega: 479.5 ms ± 3.9 ms 364.1 ms ± 7.0 ms Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * merge-ort: avoid recursing into directories when we don't need toElijah Newren2021-07-201-3/+99
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This combines the work of the last several patches, and implements the conditions when we don't need to recurse into directories. It's perhaps easiest to see the logic by separating the fact that a directory might have both rename sources and rename destinations: * rename sources: only files present in the merge base can serve as rename sources, and only when one side deletes that file. When the tree on one side matches the merge base, that means every file within the subtree matches the merge base. This means that the skip-irrelevant-rename-detection optimization from before kicks in and we don't need any of these files as rename sources. * rename destinations: the tree that does not match the merge base might have newly added and hence unmatched destination files. This is what usually prevents us from doing trivial directory resolutions in the merge machinery. However, the fact that we have deferred recursing into this directory until the end means we know whether there are any unmatched relevant potential rename sources elsewhere in this merge. If there are no unmatched such relevant sources anywhere, then there is no need to look for unmatched potential rename destinations to match them with. This informs our algorithm: * Search through relevant_sources; if we have entries, they better all be reflected in cached_pairs or cached_irrelevant, otherwise they represent an unmatched potential rename source (causing the optimization to be disallowed). * For any relevant_source represented in cached_pairs, we do need to to make sure to get the destination for each source, meaning we need to recurse into any ancestor directories of those destinations. * Once we've recursed into all the rename destinations for any relevant_sources in cached_pairs, we can then do the trivial directory resolution for the remaining directories. For the testcases mentioned in commit 557ac0350d ("merge-ort: begin performance work; instrument with trace2_region_* calls", 2020-10-28), this change improves the performance as follows: Before After no-renames: 5.235 s ± 0.042 s 205.1 ms ± 3.8 ms mega-renames: 9.419 s ± 0.107 s 1.564 s ± 0.010 s just-one-mega: 480.1 ms ± 3.9 ms 479.5 ms ± 3.9 ms Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * merge-ort: defer recursing into directories when merge base is matchedElijah Newren2021-07-201-2/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When one side of history matches the merge base (including when the merge base has no entry for the given directory), have collect_merge_info_callback() defer recursing into the directory. To ensure those entries are eventually handled, add a call to handled_deferred_entries() in collect_merge_info() after traverse_trees() returns. Note that the condition in collect_merge_info_callback() may look more complicated than necessary at first glance; renames->trivial_merges_okay[side] is always true until handle_deferred_entries() is called, and possible_trivial_merges[side] is always empty right now (and in the future won't be filled until handle_deferred_entries() is called). However, when handle_deferred_entries() calls traverse_trees() for the relevant deferred directories, those traverse_trees() calls will once again end up in collect_merge_info_callback() for all the entries under those subdirectories. The extra conditions are there for such deferred cases and will be used more as we do more with those variables. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * merge-ort: add a handle_deferred_entries() helper functionElijah Newren2021-07-201-0/+64
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to allow trivial directory resolution, we first need to be able to gather more information to determine if the optimization is safe. To enable that, we need a way of deferring the recursion into the directory until a later time. Naturally, deferring the entry into a subtree means that we need some function that will later recurse into the subdirectory exactly the same way that collect_merge_info_callback() would have done. Add a helper function that does this. For now this function is not used but a subsequent commit will change that. Future commits will also make the function sometimes resolve directories instead of traversing inside. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * merge-ort: add data structures for allowable trivial directory resolvesElijah Newren2021-07-201-0/+61
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As noted a few commits ago, we can resolve individual files early if all three sides of the merge have a file at the path and two of the three sides match. We would really like to do the same thing with directories, because being able to do a trivial directory resolve means we don't have to recurse into the directory, potentially saving us a huge amount of time in both collect_merge_info() and process_entries(). Unfortunately, resolving directories early would mean missing any renames whose source or destination is underneath that directory. If we somehow knew there weren't any renames under the directory in question, then we could resolve it early. Sadly, it is impossible to determine whether there are renames under the directory in question without recursing into it, and this has traditionally kept us from ever implementing such an optimization. In commit f89b4f2bee ("merge-ort: skip rename detection entirely if possible", 2021-03-11), we added an additional reason that rename detection could be skipped entirely -- namely, if no *relevant* sources were present. Without completing collect_merge_info_callback(), we do not yet know if there are no relevant sources. However, we do know that if the current directory on one side matches the merge base, then every source file within that directory will not be RELEVANT_CONTENT, and a few simple checks can often let us rule out RELEVANT_LOCATION as well. This suggests we can just defer recursing into such directories until the end of collect_merge_info. Since the deferred directories are known to not add any relevant sources due to the above properties, then if there are no relevant sources after we've traversed all paths other than the deferred ones, then we know there are not any relevant sources. Under those conditions, rename detection is unnecessary, and that means we can resolve the deferred directories without recursing into them. Note that the logic for skipping rename detection was also modified further in commit 76e253793c ("merge-ort, diffcore-rename: employ cached renames when possible", 2021-01-30); in particular rename detection can be skipped if we already have cached renames for each relevant source. We can take advantage of this information as well with our deferral of recursing into directories where one side matches the merge base. Add some data structures that we will use to do these deferrals, with some lengthy comments explaining their purpose. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * merge-ort: add some more explanations in collect_merge_info_callback()Elijah Newren2021-07-201-5/+15
| | | | | | | | | | | | | | | | | | | | | | The previous patch possibly raises some questions about whether additional cases in collect_merge_info_callback() can be handled early. Add some explanations in the form of comments to help explain these better. While we're at it, add a few comments to denote what a few boolean '0' or '1' values stand for. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
| * merge-ort: resolve paths early when we have sufficient informationElijah Newren2021-07-201-0/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When there are no directories involved at a given path, and all three sides have a file at that path, and two of the three sides of history match, we can immediately resolve the merge of that path in collect_merge_info() and do not need to wait until process_entries(). This is actually a very minor improvement: half the time when I run it, I see an improvement; the other half a slowdown. It seems to be in the range of noise. However, this idea serves as the beginning of some bigger optimizations coming in the following patches. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
* | Merge branch 'en/rename-limits-doc'Junio C Hamano2021-07-281-1/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Documentation on "git diff -l<n>" and diff.renameLimit have been updated, and the defaults for these limits have been raised. * en/rename-limits-doc: rename: bump limit defaults yet again diffcore-rename: treat a rename_limit of 0 as unlimited doc: clarify documentation for rename/copy limits diff: correct warning message when renameLimit exceeded
| * | rename: bump limit defaults yet againElijah Newren2021-07-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These were last bumped in commit 92c57e5c1d29 (bump rename limit defaults (again), 2011-02-19), and were bumped both because processors had gotten faster, and because people were getting ugly merges that caused problems and reporting it to the mailing list (suggesting that folks were willing to spend more time waiting). Since that time: * Linus has continued recommending kernel folks to set diff.renameLimit=0 (maps to 32767, currently) * Folks with repositories with lots of renames were happy to set merge.renameLimit above 32767, once the code supported that, to get correct cherry-picks * Processors have gotten faster * It has been discovered that the timing methodology used last time probably used too large example files. The last point is probably worth explaining a bit more: * The "average" file size used appears to have been average blob size in the linux kernel history at the time (probably v2.6.25 or something close to it). * Since bigger files are modified more frequently, such a computation weights towards larger files. * Larger files may be more likely to be modified over time, but are not more likely to be renamed -- the mean and median blob size within a tree are a bit higher than the mean and median of blob sizes in the history leading up to that version for the linux kernel. * The mean blob size in v2.6.25 was half the average blob size in history leading to that point * The median blob size in v2.6.25 was about 40% of the mean blob size in v2.6.25. * Since the mean blob size is more than double the median blob size, any file as big as the mean will not be compared to any files of median size or less (because they'd be more than 50% dissimilar). * Since it is the number of files compared that provides the O(n^2) behavior, median-sized files should matter more than mean-sized ones. The combined effect of the above is that the file size used in past calculations was likely about 5x too large. Combine that with a CPU performance improvement of ~30%, and we can increase the limits by a factor of sqrt(5/(1-.3)) = 2.67, while keeping the original stated time limits. Keeping the same approximate time limit probably makes sense for diff.renameLimit (there is no progress feedback in e.g. git log -p), but the experience above suggests merge.renameLimit could be extended significantly. In fact, it probably would make sense to have an unlimited default setting for merge.renameLimit, but that would likely need to be coupled with changes to how progress is displayed. (See https://lore.kernel.org/git/YOx+Ok%2FEYvLqRMzJ@coredump.intra.peff.net/ for details in that area.) For now, let's just bump the approximate time limit from 10s to 1m. (Note: We do not want to use actual time limits, because getting results that depend on how loaded your system is that day feels bad, and because we don't discover that we won't get all the renames until after we've put in a lot of work rather than just upfront telling the user there are too many files involved.) Using the original time limit of 2s for diff.renameLimit, and bumping merge.renameLimit from 10s to 60s, I found the following timings using the simple script at the end of this commit message (on an AWS c5.xlarge which reports as "Intel(R) Xeon(R) Platinum 8124M CPU @ 3.00GHz"): N Timing 1300 1.995s 7100 59.973s So let's round down to nice even numbers and bump the limits from 400->1000, and from 1000->7000. Here is the measure_rename_perf script (adapted from https://lore.kernel.org/git/20080211113516.GB6344@coredump.intra.peff.net/ in particular to avoid triggering the linear handling from basename-guided rename detection): #!/bin/bash n=$1; shift rm -rf repo mkdir repo && cd repo git init -q -b main mkdata() { mkdir $1 for i in `seq 1 $2`; do (sed "s/^/$i /" <../sample echo tag: $1 ) >$1/$i done } mkdata initial $n git add . git commit -q -m initial mkdata new $n git add . cd new for i in *; do git mv $i $i.renamed; done cd .. git rm -q -rf initial git commit -q -m new time git diff-tree -M -l0 --summary HEAD^ HEAD Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
* | | Merge branch 'ab/attribute-format'Junio C Hamano2021-07-281-0/+1
|\ \ \ | |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Many "printf"-like helper functions we have have been annotated with __attribute__() to catch placeholder/parameter mismatches. * ab/attribute-format: advice.h: add missing __attribute__((format)) & fix usage *.h: add a few missing __attribute__((format)) *.c static functions: add missing __attribute__((format)) sequencer.c: move static function to avoid forward decl *.c static functions: don't forward-declare __attribute__
| * | *.c static functions: add missing __attribute__((format))Ævar Arnfjörð Bjarmason2021-07-131-0/+1
| |/ | | | | | | | | | | | | | | Add missing __attribute__((format)) function attributes to various "static" functions that take printf arguments. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
* | Merge branch 'ab/struct-init'Junio C Hamano2021-07-161-2/+2
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Code cleanup around struct_type_init() functions. * ab/struct-init: string-list.h users: change to use *_{nodup,dup}() string-list.[ch]: add a string_list_init_{nodup,dup}() dir.[ch]: replace dir_init() with DIR_INIT *.c *_init(): define in terms of corresponding *_INIT macro *.h: move some *_INIT to designated initializers
| * | string-list.h users: change to use *_{nodup,dup}()Ævar Arnfjörð Bjarmason2021-07-011-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change all in-tree users of the string_list_init(LIST, BOOL) API to use string_list_init_{nodup,dup}(LIST) instead. As noted in the preceding commit let's leave the now-unused string_list_init() wrapper in-place for any in-flight users, it can be removed at some later date. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
* | | Merge branch 'en/merge-dir-rename-corner-case-fix'Junio C Hamano2021-07-161-1/+5
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The merge code had funny interactions between content based rename detection and directory rename detection. * en/merge-dir-rename-corner-case-fix: merge-recursive: handle rename-to-self case merge-ort: ensure we consult df_conflict and path_conflicts t6423: test directory renames causing rename-to-self
| * | | merge-ort: ensure we consult df_conflict and path_conflictsElijah Newren2021-06-301-1/+5
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Path conflicts (typically rename path conflicts, e.g. rename/rename(1to2) or rename/add/delete), and directory/file conflicts should obviously result in files not being marked as clean in the merge. We had a codepath where we missed consulting the path_conflict and df_conflict flags, based on match_mask. Granted, it requires an unusual setup to trigger this codepath (directory rename causing rename-to-self is the only case I can think of), but we still need to handle it. To make it clear that we have audited the other codepaths that do not explicitly mention these flags, add some assertions that the flags are not set. Reported-by: Anders Kaseorg <andersk@mit.edu> Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>