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author | Jeff Layton <jlayton@kernel.org> | 2020-04-02 01:27:25 +0300 |
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committer | Ilya Dryomov <idryomov@gmail.com> | 2020-06-01 14:22:52 +0300 |
commit | d67c72e6cce99eab5ab9d62c599e33e5141ff8b4 (patch) | |
tree | 9f615fbcc18b0ce30ac10f6a6809691c38f5359b /fs/ceph/mds_client.h | |
parent | 1cf03a68e791b1673bc4daaa88a0820f34f538f8 (diff) | |
download | linux-d67c72e6cce99eab5ab9d62c599e33e5141ff8b4.tar.xz |
ceph: request expedited service on session's last cap flush
When flushing a lot of caps to the MDS's at once (e.g. for syncfs),
we can end up waiting a substantial amount of time for MDS replies, due
to the fact that it may delay some of them so that it can batch them up
together in a single journal transaction. This can lead to stalls when
calling sync or syncfs.
What we'd really like to do is request expedited service on the _last_
cap we're flushing back to the server. If the CHECK_CAPS_FLUSH flag is
set on the request and the current inode was the last one on the
session->s_cap_dirty list, then mark the request with
CEPH_CLIENT_CAPS_SYNC.
Note that this heuristic is not perfect. New inodes can race onto the
list after we've started flushing, but it does seem to fix some common
use cases.
URL: https://tracker.ceph.com/issues/44744
Reported-by: Jan Fajerski <jfajerski@suse.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Diffstat (limited to 'fs/ceph/mds_client.h')
0 files changed, 0 insertions, 0 deletions