| cedfa028 | 11-Mar-2026 |
Sergey Senozhatsky <senozhatsky@chromium.org> |
zram: remove chained recompression
Chained recompression has unpredictable behavior and is not useful in practice.
First, systems usually configure just one alternative recompression algorithm, whi
zram: remove chained recompression
Chained recompression has unpredictable behavior and is not useful in practice.
First, systems usually configure just one alternative recompression algorithm, which has slower compression/decompression but better compression ratio. A single alternative algorithm doesn't need chaining.
Second, even with multiple recompression algorithms, chained recompression is suboptimal. If a lower priority algorithm succeeds, the page is never attempted with a higher priority algorithm, leading to worse memory savings. If a lower priority algorithm fails, the page is still attempted with a higher priority algorithm, wasting resources on the failed lower priority attempt.
In either case, the system would be better off targeting a specific priority directly.
Chained recompression also significantly complicates the code. Remove it.
Link: https://lkml.kernel.org/r/20260311084312.1766036-6-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Brian Geffon <bgeffon@google.com> Cc: gao xu <gaoxu2@honor.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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| 2502673a | 01-Dec-2025 |
Sergey Senozhatsky <senozhatsky@chromium.org> |
zram: document writeback_batch_size
Add missing writeback_batch_size documentation.
Link: https://lkml.kernel.org/r/20251201094754.4149975-4-senozhatsky@chromium.org Signed-off-by: Sergey Senozhats
zram: document writeback_batch_size
Add missing writeback_batch_size documentation.
Link: https://lkml.kernel.org/r/20251201094754.4149975-4-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Brian Geffon <bgeffon@google.com> Cc: David Stevens <stevensd@google.com> Cc: Minchan Kim <minchan@google.com> Cc: Richard Chang <richardycc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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| e899007a | 02-Sep-2024 |
Sergey Senozhatsky <senozhatsky@chromium.org> |
zram: support priority parameter in recompression
recompress device attribute supports alg=NAME parameter so that we can specify only one particular algorithm we want to perform recompression with.
zram: support priority parameter in recompression
recompress device attribute supports alg=NAME parameter so that we can specify only one particular algorithm we want to perform recompression with. However, with algo params we now can have several exactly same secondary algorithms but each with its own params tuning (e.g. priority 1 configured to use more aggressive level, and priority 2 configured to use a pre-trained dictionary). Support priority=NUM parameter so that we can correctly determine which secondary algorithm we want to use.
Link: https://lkml.kernel.org/r/20240902105656.1383858-25-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Nick Terrell <terrelln@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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