From 001d9273570115b2eb360d5452bbc46f6cc063a1 Mon Sep 17 00:00:00 2001 From: Sergey Senozhatsky Date: Wed, 9 Nov 2022 20:50:36 +0900 Subject: zram: add recompression algorithm sysfs knob Introduce recomp_algorithm sysfs knob that controls secondary algorithm selection used for recompression. We will support up to 3 secondary compression algorithms which are sorted in order of their priority. To select an algorithm user has to provide its name and priority: echo "algo=zstd priority=1" > /sys/block/zramX/recomp_algorithm echo "algo=deflate priority=2" > /sys/block/zramX/recomp_algorithm During recompression zram iterates through the list of registered secondary algorithms in order of their priorities. We also have a short version for cases when there is only one secondary compression algorithm: echo "algo=zstd" > /sys/block/zramX/recomp_algorithm This will register zstd as the secondary algorithm with priority 1. Link: https://lkml.kernel.org/r/20221109115047.2921851-3-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky Acked-by: Minchan Kim Cc: Alexey Romanov Cc: Nhat Pham Cc: Nitin Gupta Cc: Suleiman Souhlal Signed-off-by: Andrew Morton --- drivers/block/zram/zram_drv.c | 124 +++++++++++++++++++++++++++++++++++------- 1 file changed, 105 insertions(+), 19 deletions(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index fbe46c6177fd..8ea4908f5961 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -997,31 +997,28 @@ static ssize_t max_comp_streams_store(struct device *dev, return len; } -static ssize_t comp_algorithm_show(struct device *dev, - struct device_attribute *attr, char *buf) +static void comp_algorithm_set(struct zram *zram, u32 prio, const char *alg) { - size_t sz; - struct zram *zram = dev_to_zram(dev); + /* Do not free statically defined compression algorithms */ + if (zram->comp_algs[prio] != default_compressor) + kfree(zram->comp_algs[prio]); + + zram->comp_algs[prio] = alg; +} + +static ssize_t __comp_algorithm_show(struct zram *zram, u32 prio, char *buf) +{ + ssize_t sz; down_read(&zram->init_lock); - sz = zcomp_available_show(zram->comp_algs[ZRAM_PRIMARY_COMP], buf); + sz = zcomp_available_show(zram->comp_algs[prio], buf); up_read(&zram->init_lock); return sz; } -static void comp_algorithm_set(struct zram *zram, u32 prio, const char *alg) +static int __comp_algorithm_store(struct zram *zram, u32 prio, const char *buf) { - /* Do not kfree() algs that we didn't allocate, IOW the default ones */ - if (zram->comp_algs[prio] != default_compressor) - kfree(zram->comp_algs[prio]); - zram->comp_algs[prio] = alg; -} - -static ssize_t comp_algorithm_store(struct device *dev, - struct device_attribute *attr, const char *buf, size_t len) -{ - struct zram *zram = dev_to_zram(dev); char *compressor; size_t sz; @@ -1050,11 +1047,94 @@ static ssize_t comp_algorithm_store(struct device *dev, return -EBUSY; } - comp_algorithm_set(zram, ZRAM_PRIMARY_COMP, compressor); + comp_algorithm_set(zram, prio, compressor); up_write(&zram->init_lock); - return len; + return 0; +} + +static ssize_t comp_algorithm_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return __comp_algorithm_show(zram, ZRAM_PRIMARY_COMP, buf); +} + +static ssize_t comp_algorithm_store(struct device *dev, + struct device_attribute *attr, + const char *buf, + size_t len) +{ + struct zram *zram = dev_to_zram(dev); + int ret; + + ret = __comp_algorithm_store(zram, ZRAM_PRIMARY_COMP, buf); + return ret ? ret : len; } +#ifdef CONFIG_ZRAM_MULTI_COMP +static ssize_t recomp_algorithm_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct zram *zram = dev_to_zram(dev); + ssize_t sz = 0; + u32 prio; + + for (prio = ZRAM_SECONDARY_COMP; prio < ZRAM_MAX_COMPS; prio++) { + if (!zram->comp_algs[prio]) + continue; + + sz += scnprintf(buf + sz, PAGE_SIZE - sz - 2, "#%d: ", prio); + sz += __comp_algorithm_show(zram, prio, buf + sz); + } + + return sz; +} + +static ssize_t recomp_algorithm_store(struct device *dev, + struct device_attribute *attr, + const char *buf, + size_t len) +{ + struct zram *zram = dev_to_zram(dev); + int prio = ZRAM_SECONDARY_COMP; + char *args, *param, *val; + char *alg = NULL; + int ret; + + args = skip_spaces(buf); + while (*args) { + args = next_arg(args, ¶m, &val); + + if (!*val) + return -EINVAL; + + if (!strcmp(param, "algo")) { + alg = val; + continue; + } + + if (!strcmp(param, "priority")) { + ret = kstrtoint(val, 10, &prio); + if (ret) + return ret; + continue; + } + } + + if (!alg) + return -EINVAL; + + if (prio < ZRAM_SECONDARY_COMP || prio >= ZRAM_MAX_COMPS) + return -EINVAL; + + ret = __comp_algorithm_store(zram, prio, alg); + return ret ? ret : len; +} +#endif + static ssize_t compact_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { @@ -1895,6 +1975,9 @@ static DEVICE_ATTR_WO(writeback); static DEVICE_ATTR_RW(writeback_limit); static DEVICE_ATTR_RW(writeback_limit_enable); #endif +#ifdef CONFIG_ZRAM_MULTI_COMP +static DEVICE_ATTR_RW(recomp_algorithm); +#endif static struct attribute *zram_disk_attrs[] = { &dev_attr_disksize.attr, @@ -1918,6 +2001,9 @@ static struct attribute *zram_disk_attrs[] = { &dev_attr_bd_stat.attr, #endif &dev_attr_debug_stat.attr, +#ifdef CONFIG_ZRAM_MULTI_COMP + &dev_attr_recomp_algorithm.attr, +#endif NULL, }; @@ -1997,7 +2083,7 @@ static int zram_add(void) if (ret) goto out_cleanup_disk; - zram->comp_algs[ZRAM_PRIMARY_COMP] = default_compressor; + comp_algorithm_set(zram, ZRAM_PRIMARY_COMP, default_compressor); zram_debugfs_register(zram); pr_info("Added device: %s\n", zram->disk->disk_name); -- cgit v1.2.3