5c480a6966
[ Upstream commit 6a3afb6ac6dfab158ebdd4b87941178f58c8939f ] Current jbd2 only add REQ_SYNC for descriptor block, metadata log buffer, commit buffer and superblock buffer, the submitted IO could be throttled by writeback throttle in block layer, that could lead to priority inversion in some cases. The log IO looks like a kind of high priority metadata IO, so it should not be throttled by WBT like QOS policies in block layer, let's add REQ_SYNC | REQ_IDLE to exempt from writeback throttle, and also add REQ_META together indicates it's a metadata IO. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20231129114740.2686201-2-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Sasha Levin <sashal@kernel.org>
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.