Patch series "mm/damon: fix quota status loss due to online tunings". DAMON_RECLAIM and DAMON_LRU_SORT is not preserving internal quota status when applying new user parameters, and hence could cause temporal quota accuracy degradation. Fix it by preserving the status. This patch (of 2): For online parameters change, DAMON_RECLAIM creates new scheme based on latest values of the parameters and replaces the old scheme with the new one. When creating it, the internal status of the quota of the old scheme is not preserved. As a result, charging of the quota starts from zero after the online tuning. The data that collected to estimate the throughput of the scheme's action is also reset, and therefore the estimation should start from the scratch again. Because the throughput estimation is being used to convert the time quota to the effective size quota, this could result in temporal time quota inaccuracy. It would be recovered over time, though. In short, the quota accuracy could be temporarily degraded after online parameters update. Fix the problem by checking the case and copying the internal fields for the status. Link: https://lkml.kernel.org/r/20240216194025.9207-1-sj@kernel.org Link: https://lkml.kernel.org/r/20240216194025.9207-2-sj@kernel.org Fixes: e035c280f6df ("mm/damon/reclaim: support online inputs update") Signed-off-by: SeongJae Park <sj@kernel.org> Cc: <stable@vger.kernel.org> [5.19+] Signed-off-by: Andrew Morton <akpm@linux-foundation.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.
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