From: Jeff Hostetler <jeffhost@xxxxxxxxxxxxx> Set the `FSMONITOR_CHANGED` bit on `istate->cache_changed` when the fsmonitor response contains a different token to ensure that the index is written to disk. Normally, when the fsmonitor response includes a tracked file, the index is always updated. Similarly, the index might be updated when the response alters the untracked-cache (when enabled). However, in cases where neither of those cause the index to be considered changed, the fsmonitor response is wasted. And subsequent commands will continue to make requests with the same token and if there have not been any changes in the working directory, they will receive the same response. This was observed on Windows after a large checkout. On Windows, the kernel emits events for the files that are changed as they are changed. However, it might delay events for the containing directories until the system is more idle (or someone scans the directory (so it seems)). The first status following a checkout would get the list of files. The subsequent status commands would get the list of directories as the events trickled out. But they would never catch up because the token was not advanced because the index wasn't updated. This list of directories caused `wt_status_collect_untracked()` to unnecessarily spend time actually scanning them during each command. Signed-off-by: Jeff Hostetler <jeffhost@xxxxxxxxxxxxx> --- fsmonitor.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/fsmonitor.c b/fsmonitor.c index d7e18fc8cd47..8b544e31f29f 100644 --- a/fsmonitor.c +++ b/fsmonitor.c @@ -353,6 +353,16 @@ void refresh_fsmonitor(struct index_state *istate) } strbuf_release(&query_result); + /* + * If the fsmonitor response and the subsequent scan of the disk + * did not cause the in-memory index to be marked dirty, then force + * it so that we advance the fsmonitor token in our extension, so + * that future requests don't keep re-requesting the same range. + */ + if (istate->fsmonitor_last_update && + strcmp(istate->fsmonitor_last_update, last_update_token.buf)) + istate->cache_changed |= FSMONITOR_CHANGED; + /* Now that we've updated istate, save the last_update_token */ FREE_AND_NULL(istate->fsmonitor_last_update); istate->fsmonitor_last_update = strbuf_detach(&last_update_token, NULL); -- gitgitgadget
