From 4eac932103a5d8c3a1bdf6776dbc1a178c31d896 Mon Sep 17 00:00:00 2001 From: Sergey Senozhatsky Date: Mon, 2 Sep 2024 19:56:03 +0900 Subject: [PATCH] zram: introduce algorithm_params device attribute This attribute is used to setup compression algorithms' parameters, so we can tweak algorithms' characteristics. At this point only 'level' is supported (to be extended in the future). Each call sets up parameters for one particular algorithm, which should be specified either by the algorithm's priority or algo name. This is expected to be called after corresponding algorithm is selected via comp_algorithm or recomp_algorithm. echo "priority=0 level=1" > /sys/block/zram0/algorithm_params or echo "algo=zstd level=1" > /sys/block/zram0/algorithm_params Link: https://lkml.kernel.org/r/20240902105656.1383858-16-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky Cc: Minchan Kim Cc: Nick Terrell Signed-off-by: Andrew Morton --- Documentation/ABI/testing/sysfs-block-zram | 7 +++ Documentation/admin-guide/blockdev/zram.rst | 1 + drivers/block/zram/zram_drv.c | 68 +++++++++++++++++++++ 3 files changed, 76 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-block-zram b/Documentation/ABI/testing/sysfs-block-zram index 628a00fb20a9..1ef69e0271f9 100644 --- a/Documentation/ABI/testing/sysfs-block-zram +++ b/Documentation/ABI/testing/sysfs-block-zram @@ -151,3 +151,10 @@ Contact: Sergey Senozhatsky Description: The recompress file is write-only and triggers re-compression with secondary compression algorithms. + +What: /sys/block/zram/algorithm_params +Date: August 2024 +Contact: Sergey Senozhatsky +Description: + The algorithm_params file is write-only and is used to setup + compression algorithm parameters. diff --git a/Documentation/admin-guide/blockdev/zram.rst b/Documentation/admin-guide/blockdev/zram.rst index 181d55d64326..96d81dc12528 100644 --- a/Documentation/admin-guide/blockdev/zram.rst +++ b/Documentation/admin-guide/blockdev/zram.rst @@ -198,6 +198,7 @@ writeback_limit_enable RW show and set writeback_limit feature max_comp_streams RW the number of possible concurrent compress operations comp_algorithm RW show and change the compression algorithm +algorithm_params WO setup compression algorithm parameters compact WO trigger memory compaction debug_stat RO this file is used for zram debugging purposes backing_dev RW set up backend storage for zram to write out diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index ff6724bbdf91..e29e952b99c3 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -998,6 +998,72 @@ static int __comp_algorithm_store(struct zram *zram, u32 prio, const char *buf) return 0; } +static int comp_params_store(struct zram *zram, u32 prio, s32 level) +{ + zram->params[prio].level = level; + return 0; +} + +static ssize_t algorithm_params_store(struct device *dev, + struct device_attribute *attr, + const char *buf, + size_t len) +{ + s32 prio = ZRAM_PRIMARY_COMP, level = ZCOMP_PARAM_NO_LEVEL; + char *args, *param, *val, *algo = NULL; + struct zram *zram = dev_to_zram(dev); + int ret; + + args = skip_spaces(buf); + while (*args) { + args = next_arg(args, ¶m, &val); + + if (!val || !*val) + return -EINVAL; + + if (!strcmp(param, "priority")) { + ret = kstrtoint(val, 10, &prio); + if (ret) + return ret; + continue; + } + + if (!strcmp(param, "level")) { + ret = kstrtoint(val, 10, &level); + if (ret) + return ret; + continue; + } + + if (!strcmp(param, "algo")) { + algo = val; + continue; + } + } + + /* Lookup priority by algorithm name */ + if (algo) { + s32 p; + + prio = -EINVAL; + for (p = ZRAM_PRIMARY_COMP; p < ZRAM_MAX_COMPS; p++) { + if (!zram->comp_algs[p]) + continue; + + if (!strcmp(zram->comp_algs[p], algo)) { + prio = p; + break; + } + } + } + + if (prio < ZRAM_PRIMARY_COMP || prio >= ZRAM_MAX_COMPS) + return -EINVAL; + + ret = comp_params_store(zram, prio, level); + return ret ? ret : len; +} + static ssize_t comp_algorithm_show(struct device *dev, struct device_attribute *attr, char *buf) @@ -2169,6 +2235,7 @@ static DEVICE_ATTR_RW(writeback_limit_enable); static DEVICE_ATTR_RW(recomp_algorithm); static DEVICE_ATTR_WO(recompress); #endif +static DEVICE_ATTR_WO(algorithm_params); static struct attribute *zram_disk_attrs[] = { &dev_attr_disksize.attr, @@ -2196,6 +2263,7 @@ static struct attribute *zram_disk_attrs[] = { &dev_attr_recomp_algorithm.attr, &dev_attr_recompress.attr, #endif + &dev_attr_algorithm_params.attr, NULL, };