Jeff Layton
d67c72e6cc
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>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.