From: Utsav Shah via GitGitGadget Date: Wed, 20 Nov 2019 08:32:16 GMT Subject: [PATCH v4 0/1] unpack-trees: skip stat on fsmonitor-valid files Message-ID: In-Reply-To: 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. Changes since the last version are: * The sanity checks around accessing the fsmonitor_dirty bitmap have been moved to another patch, which is in message id [1] * Unintended indentation changes in fsmonitor have been removed * A comment explaining what untracked->use_fsmonitor means has been re-added (it was dropped in the previous version) * A few "helped-by" entries have been added to the patch 1: (xmqqzhh0d0ma.fsf@gitster-ct.c.googlers.com) Helped-by: Junio C Hamano gitster@pobox.com [gitster@pobox.com]Helped-by: Kevin Willford Kevin.Willford@microsoft.com [Kevin.Willford@microsoft.com] Signed-off-by: Utsav Shah utsav@dropbox.com [utsav@dropbox.com] Utsav Shah (1): unpack-trees: skip stat on fsmonitor-valid files fsmonitor.c | 23 +++++++++++++++++------ t/t7519-status-fsmonitor.sh | 9 +++++++-- unpack-trees.c | 6 +++++- 3 files changed, 29 insertions(+), 9 deletions(-) base-commit: 566a1439f6f56c2171b8853ddbca0ad3f5098770 Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-424%2FUtsav2%2Fskip-lstat-v4 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-424/Utsav2/skip-lstat-v4 Pull-Request: https://github.com/gitgitgadget/git/pull/424 Range-diff vs v3: 1: 4bea7075cf ! 1: ea7880f2d0 unpack-trees: skip stat on fsmonitor-valid files @@ -17,52 +17,29 @@ internally) go from 8s or more to ~2s on a 250k file repository on a mac. + Changes since the last version are: + * The sanity checks around accessing the fsmonitor_dirty bitmap have + been moved to another patch, which is in message id [1] + * Unintended indentation changes in fsmonitor have been removed + * A comment explaining what untracked->use_fsmonitor means has been + re-added (it was dropped in the previous version) + * A few "helped-by" entries have been added to the patch + + [1]: (xmqqzhh0d0ma.fsf@gitster-ct.c.googlers.com) + + Helped-by: Junio C Hamano + Helped-by: Kevin Willford Signed-off-by: Utsav Shah diff --git a/fsmonitor.c b/fsmonitor.c --- 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; - -- 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); -+ 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); -+ - - trace_printf_key(&trace_fsmonitor, "read fsmonitor extension successful"); - return 0; -@@ - uint32_t ewah_size = 0; - int fixup = 0; - -- 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); -+ 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); - - put_be32(&hdr_version, INDEX_EXTENSION_VERSION); - strbuf_add(sb, &hdr_version, sizeof(uint32_t)); -@@ } if (bol < query_result.len) fsmonitor_refresh_callback(istate, buf + bol); + ++ /* Now mark the untracked cache for fsmonitor usage */ + if (istate->untracked) + istate->untracked->use_fsmonitor = 1; } else { @@ -88,11 +65,7 @@ if (istate->untracked) istate->untracked->use_fsmonitor = 0; @@ - /* 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); + (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 */ -- gitgitgadget