The index might be aware that a file hasn't modified via fsmonitor, but unpack-trees did not pay attention to it and checked via ie_match_stat which can be inefficient on certain filesystems. This significantly slows down commands that run oneway_merge, like checkout and reset --hard. This patch makes oneway_merge check whether a file is considered unchanged through fsmonitor and skips ie_match_stat on it. unpack-trees also now correctly copies over fsmonitor validity state from the source index. Finally, for correctness, we force a refresh of fsmonitor state in tweak_fsmonitor. After this change, commands like stash (that use reset --hard internally) go from 8s or more to ~2s on a 250k file repository on a mac. Signed-off-by: Utsav Shah utsav@xxxxxxxxxxx [utsav@xxxxxxxxxxx] Utsav Shah (1): unpack-trees: skip stat on fsmonitor-valid files fsmonitor.c | 39 ++++++++++++++++++++++++------------- t/t7519-status-fsmonitor.sh | 9 +++++++-- unpack-trees.c | 6 +++++- 3 files changed, 37 insertions(+), 17 deletions(-) base-commit: 566a1439f6f56c2171b8853ddbca0ad3f5098770 Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-424%2FUtsav2%2Fskip-lstat-v3 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-424/Utsav2/skip-lstat-v3 Pull-Request: https://github.com/gitgitgadget/git/pull/424 Range-diff vs v2: 1: f76ba554ed ! 1: 4bea7075cf unpack-trees: skip stat on fsmonitor-valid files @@ -23,6 +23,15 @@ --- a/fsmonitor.c +++ b/fsmonitor.c @@ + + if (pos >= istate->cache_nr) + BUG("fsmonitor_dirty has more entries than the index (%"PRIuMAX" >= %u)", +- (uintmax_t)pos, istate->cache_nr); ++ (uintmax_t)pos, istate->cache_nr); + + ce = istate->cache[pos]; + ce->ce_flags &= ~CE_FSMONITOR_VALID; +@@ } istate->fsmonitor_dirty = fsmonitor_dirty; @@ -31,7 +40,7 @@ - (uintmax_t)istate->fsmonitor_dirty->bit_size, istate->cache_nr); + if (!istate->split_index && istate->fsmonitor_dirty->bit_size > istate->cache_nr) + BUG("fsmonitor_dirty has more entries than the index (%"PRIuMAX" > %"PRIuMAX")", -+ (uintmax_t)istate->fsmonitor_dirty->bit_size, (uintmax_t)istate->cache_nr); ++ (uintmax_t)istate->fsmonitor_dirty->bit_size, (uintmax_t)istate->cache_nr); + trace_printf_key(&trace_fsmonitor, "read fsmonitor extension successful"); @@ -45,7 +54,7 @@ - (uintmax_t)istate->fsmonitor_dirty->bit_size, istate->cache_nr); + if (!istate->split_index && istate->fsmonitor_dirty->bit_size > istate->cache_nr) + BUG("fsmonitor_dirty has more entries than the index (%"PRIuMAX" > %"PRIuMAX")", -+ (uintmax_t)istate->fsmonitor_dirty->bit_size, (uintmax_t)istate->cache_nr); ++ (uintmax_t)istate->fsmonitor_dirty->bit_size, (uintmax_t)istate->cache_nr); put_be32(&hdr_version, INDEX_EXTENSION_VERSION); strbuf_add(sb, &hdr_version, sizeof(uint32_t)); @@ -57,10 +66,33 @@ + if (istate->untracked) + istate->untracked->use_fsmonitor = 1; } else { ++ ++ /* We only want to run the post index changed hook if we've actually changed entries, so keep track ++ * if we actually changed entries or not */ ++ int is_cache_changed = 0; /* Mark all entries invalid */ - for (i = 0; i < istate->cache_nr; i++) +- for (i = 0; i < istate->cache_nr; i++) +- istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID; ++ for (i = 0; i < istate->cache_nr; i++) { ++ if (istate->cache[i]->ce_flags & CE_FSMONITOR_VALID) { ++ is_cache_changed = 1; ++ istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID; ++ } ++ } + + /* If we're going to check every file, ensure we save the results */ +- istate->cache_changed |= FSMONITOR_CHANGED; ++ if (is_cache_changed) ++ istate->cache_changed |= FSMONITOR_CHANGED; + + if (istate->untracked) + istate->untracked->use_fsmonitor = 0; @@ - (uintmax_t)istate->fsmonitor_dirty->bit_size, istate->cache_nr); + /* Mark all previously saved entries as dirty */ + if (istate->fsmonitor_dirty->bit_size > istate->cache_nr) + BUG("fsmonitor_dirty has more entries than the index (%"PRIuMAX" > %u)", +- (uintmax_t)istate->fsmonitor_dirty->bit_size, istate->cache_nr); ++ (uintmax_t)istate->fsmonitor_dirty->bit_size, istate->cache_nr); ewah_each_bit(istate->fsmonitor_dirty, fsmonitor_ewah_callback, istate); - /* Now mark the untracked cache for fsmonitor usage */ @@ -71,20 +103,6 @@ ewah_free(istate->fsmonitor_dirty); - diff --git a/t/t7113-post-index-change-hook.sh b/t/t7113-post-index-change-hook.sh - --- a/t/t7113-post-index-change-hook.sh - +++ b/t/t7113-post-index-change-hook.sh -@@ - git checkout -- dir1/file1.txt && - test_path_is_file testsuccess && rm -f testsuccess && - test_path_is_missing testfailure && -- git update-index && -- test_path_is_missing testsuccess && -- test_path_is_missing testfailure && - git reset --soft && - test_path_is_missing testsuccess && - test_path_is_missing testfailure - diff --git a/t/t7519-status-fsmonitor.sh b/t/t7519-status-fsmonitor.sh --- a/t/t7519-status-fsmonitor.sh +++ b/t/t7519-status-fsmonitor.sh @@ -113,8 +131,8 @@ - write_script .git/hooks/fsmonitor-test<<-\EOF && - EOF clean_repo && -+ write_integration_script && dirty_repo && ++ write_integration_script && git add . && + write_script .git/hooks/fsmonitor-test<<-\EOF && + EOF -- gitgitgadget
