kernel/git/stable/linux.git/fs/erofs/pcpubuf.c, branch master

erofs: rename per-CPU buffers to global buffer pool and make it configurable

2024-05-08T09:12:49+00:00

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 Reviewed-by: Gao Xiang Signed-off-by: Chunhai Guo Link: https://lore.kernel.org/r/20240402100036.2673604-1-guochunhai@vivo.com Signed-off-by: Sandeep Dhavale Link: https://lore.kernel.org/r/20240408215231.3376659-1-dhavale@google.com Signed-off-by: Gao Xiang

erofs: mark z_erofs_lzma_init/erofs_pcpubuf_init w/ __init

2023-03-09T14:49:30+00:00

They are used during the erofs module init phase. Let's mark it as __init like any other function. Signed-off-by: Yangtao Li Reviewed-by: Yue Hu Reviewed-by: Gao Xiang Reviewed-by: Chao Yu Link: https://lore.kernel.org/r/20230303063731.66760-1-frank.li@vivo.com Signed-off-by: Gao Xiang

erofs: get rid of ->lru usage

2021-10-25T00:22:59+00:00

Currently, ->lru is a way to arrange non-LRU pages and has some in-kernel users. In order to minimize noticable issues of page reclaim and cache thrashing under high memory presure, limited temporary pages were all chained with ->lru and can be reused during the request. However, it seems that ->lru could be removed when folio is landing. Let's use page->private to chain temporary pages for now instead and transform EROFS formally after the topic of the folio / file page design is finalized. Link: https://lore.kernel.org/r/20211022090120.14675-1-hsiangkao@linux.alibaba.com Cc: Matthew Wilcox Reviewed-by: Kent Overstreet Reviewed-by: Chao Yu Signed-off-by: Gao Xiang

erofs: introduce multipage per-CPU buffers

2021-04-09T19:19:59+00:00

To deal the with the cases which inplace decompression is infeasible for some inplace I/O. Per-CPU buffers was introduced to get rid of page allocation latency and thrash for low-latency decompression algorithms such as lz4. For the big pcluster feature, introduce multipage per-CPU buffers to keep such inplace I/O pclusters temporarily as well but note that per-CPU pages are just consecutive virtually. When a new big pcluster fs is mounted, its max pclustersize will be read and per-CPU buffers can be growed if needed. Shrinking adjustable per-CPU buffers is more complex (because we don't know if such size is still be used), so currently just release them all when unloading. Link: https://lore.kernel.org/r/20210409190630.19569-1-xiang@kernel.org Acked-by: Chao Yu Signed-off-by: Gao Xiang