forked from Minki/linux
mainlining shenanigans
b0853ab4a2
When the margin drops below the minimum on a donating iocg, donation is immediately canceled in full. There are a couple shortcomings with the current behavior. * It's abrupt. A small temporary budget deficit can lead to a wide swing in weight allocation and a large surplus. * It's open coded in the issue path but not implemented for the merge path. A series of merges at a low inuse can make the iocg incur debts and stall incorrectly. This patch reimplements in-period donation snapbacks so that * inuse adjustment and cost calculations are factored into adjust_inuse_and_calc_cost() which is called from both the issue and merge paths. * Snapbacks are more gradual. It occurs in quarter steps. * A snapback triggers if the margin goes below the low threshold and is lower than the budget at the time of the last adjustment. * For the above, __propagate_weights() stores the margin in iocg->saved_margin. Move iocg->last_inuse storing together into __propagate_weights() for consistency. * Full snapback is guaranteed when there are waiters. * With precise donation and gradual snapbacks, inuse adjustments are now a lot more effective and the value of scaling inuse on weight changes isn't clear. Removed inuse scaling from weight_update(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> |
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| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| 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 | ||
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.