7c107afb87
In the situation where the log is full and the CIL has not recently flushed, the AIL push threshold is throttled back to the where the last write of the head of the log was completed. This is stored in log->l_last_sync_lsn. Hence if the CIL holds > 25% of the log space pinned by flushes and/or aggregation in progress, we can get the situation where the head of the log lags a long way behind the reservation grant head. When this happens, the AIL push target is trimmed back from where the reservation grant head wants to push the log tail to, back to where the head of the log currently is. This means the push target doesn't reach far enough into the log to actually move the tail before the transaction reservation goes to sleep. When the CIL push completes, it moves the log head forward such that the AIL push target can now be moved, but that has no mechanism for puhsing the log tail. Further, if the next tail movement of the log is not large enough wake the waiter (i.e. still not enough space for it to have a reservation granted), we don't wake anything up, and hence we do not update the AIL push target to take into account the head of the log moving and allowing the push target to be moved forwards. To avoid this particular condition, if we fail to wake the first waiter on the grant head because we don't have enough space, push on the AIL again. This will pick up any movement of the log head and allow the push target to move forward due to completion of CIL pushing. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> |
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| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
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.