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0f6273ab |
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02-Apr-2024 |
Chunhai Guo <guochunhai@vivo.com> |
erofs: add a reserved buffer pool for lz4 decompression This adds a special global buffer pool (in the end) for reserved pages. Using a reserved pool for LZ4 decompression significantly reduces the time spent on extra temporary page allocation for the extreme cases in low memory scenarios. The table below shows the reduction in time spent on page allocation for LZ4 decompression when using a reserved pool. The results were obtained from multi-app launch benchmarks on ARM64 Android devices running the 5.15 kernel with an 8-core CPU and 8GB of memory. In the benchmark, we launched 16 frequently-used apps, and the camera app was the last one in each round. The data in the table is the average time of camera app for each round. After using the reserved pool, there was an average improvement of 150ms in the overall launch time of our camera app, which was obtained from the systrace log. +--------------+---------------+--------------+---------+ | | w/o page pool | w/ page pool | diff | +--------------+---------------+--------------+---------+ | Average (ms) | 3434 | 21 | -99.38% | +--------------+---------------+--------------+---------+ Based on the benchmark logs, 64 pages are sufficient for 95% of scenarios. This value can be adjusted with a module parameter `reserved_pages`. The default value is 0. This pool is currently only used for the LZ4 decompressor, but it can be applied to more decompressors if needed. Signed-off-by: Chunhai Guo <guochunhai@vivo.com> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Link: https://lore.kernel.org/r/20240402131523.2703948-1-guochunhai@vivo.com Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
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f36f3010 |
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02-Apr-2024 |
Chunhai Guo <guochunhai@vivo.com> |
erofs: rename per-CPU buffers to global buffer pool and make it configurable It will cost more time if compressed buffers are allocated on demand for low-latency algorithms (like lz4) so EROFS uses per-CPU buffers to keep compressed data if in-place decompression is unfulfilled. While it is kind of wasteful of memory for a device with hundreds of CPUs, and only a small number of CPUs concurrently decompress most of the time. This patch renames it as 'global buffer pool' and makes it configurable. This allows two or more CPUs to share a common buffer to reduce memory occupation. Suggested-by: Gao Xiang <xiang@kernel.org> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Chunhai Guo <guochunhai@vivo.com> Link: https://lore.kernel.org/r/20240402100036.2673604-1-guochunhai@vivo.com Signed-off-by: Sandeep Dhavale <dhavale@google.com> Link: https://lore.kernel.org/r/20240408215231.3376659-1-dhavale@google.com Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
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cacd5b04 |
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01-Apr-2024 |
Chunhai Guo <guochunhai@vivo.com> |
erofs: rename utils.c to zutil.c Currently, utils.c is only useful if CONFIG_EROFS_FS_ZIP is on. So let's rename it to zutil.c as well as avoid its inclusion if CONFIG_EROFS_FS_ZIP is explicitly disabled. Signed-off-by: Chunhai Guo <guochunhai@vivo.com> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Link: https://lore.kernel.org/r/20240401135550.2550043-1-guochunhai@vivo.com Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
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