Re: [PATCH v4 1/1] unpack-trees: skip stat on fsmonitor-valid files
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Nov 21, 2019, 04:15 UTC
- Message-ID
- <xmqqd0dlamq2.fsf@gitster-ct.c.googlers.com>
- In-Reply-To
- <ea7880f2d07ef65f8b41f6786ff789f7a0ff8fd7.1574238737.git.gitgitgadget@gmail.com>
"Utsav Shah via GitGitGadget" <gitgitgadget@gmail.com> writes:
Show 12 quoted lines
> From: Utsav Shah <utsav@dropbox.com> > > 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.
Instead of saying "also now correctly copies..." as if it started working correctly by accident, be more assertive and actively make it so ;-)
Check if a file is unchanged by fsmonitor in oneway_merge(), and
avoid unnecessary calls to ie_match_stat(). Copy the fsmonitor
validity state from the source index to the destination index in
unpack_trees(). Force a refresh of the fsmonitor state in
tweak_fsmonitor(), which is called after the index file is read
from the disk, for correctness.perhaps.
> 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.
Good.
Show 10 quoted lines
> > 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)
The above is for the cover letter or after the three-dash lines, and not for the log message.
Show 25 quoted lines
> Helped-by: Junio C Hamano <gitster@pobox.com>
> Helped-by: Kevin Willford <Kevin.Willford@microsoft.com>
> Signed-off-by: Utsav Shah <utsav@dropbox.com>
> ---
> fsmonitor.c | 23 +++++++++++++++++------
> t/t7519-status-fsmonitor.sh | 9 +++++++--
> unpack-trees.c | 6 +++++-
> 3 files changed, 29 insertions(+), 9 deletions(-)
>
> diff --git a/fsmonitor.c b/fsmonitor.c
> index 1f4aa1b150..0d270da80f 100644
> --- a/fsmonitor.c
> +++ b/fsmonitor.c
> @@ -189,13 +189,26 @@ void refresh_fsmonitor(struct index_state *istate)
> }
> 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 {
> +
> + /* 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 */Multi-line comment style.
Show 5 quoted lines
> + int is_cache_changed = 0;
> /* Mark all entries invalid */
> - for (i = 0; i < istate->cache_nr; i++)
> - istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID;
> + for (i = 0; i < istate->cache_nr; i++) {Lack of blank line between the last decl and the first stmt. Probably the blank should go before "/* Mark all ...".
Show 11 quoted lines
> @@ -257,9 +270,7 @@ void tweak_fsmonitor(struct index_state *istate) > (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 */ > - if (istate->untracked) > - istate->untracked->use_fsmonitor = 1; > + refresh_fsmonitor(istate); > } > > ewah_free(istate->fsmonitor_dirty);
Looks good.
Thanks.