Message ID | 20230710221659.2473460-3-minchan@kernel.org (mailing list archive) |
---|---|
State | New |
Headers | show |
Series | zram: use frontswap for zram swap usecase | expand |
Hello, On Mon, Jul 10, 2023 at 03:16:58PM -0700, Minchan Kim wrote: > With frontswap, zram can perform swapout 13% faster, which restores > its original performance with rw_page. > > 200M swapout using MADV_PAGEOUT: > Before: 4355ms After: 3786ms > > Signed-off-by: Minchan Kim <minchan@kernel.org> > --- > drivers/block/zram/Kconfig | 1 + > drivers/block/zram/zram_drv.c | 98 +++++++++++++++++++++++++++++++++++ > drivers/block/zram/zram_drv.h | 1 + > 3 files changed, 100 insertions(+) > > diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig > index 0386b7da02aa..a841d6d14c74 100644 > --- a/drivers/block/zram/Kconfig > +++ b/drivers/block/zram/Kconfig > @@ -4,6 +4,7 @@ config ZRAM > depends on BLOCK && SYSFS && MMU > depends on CRYPTO_LZO || CRYPTO_ZSTD || CRYPTO_LZ4 || CRYPTO_LZ4HC || CRYPTO_842 > select ZSMALLOC > + select FRONTSWAP > help > Creates virtual block devices called /dev/zramX (X = 0, 1, ...). > Pages written to these disks are compressed and stored in memory > diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c > index 5d258a28ec43..5e973c982235 100644 > --- a/drivers/block/zram/zram_drv.c > +++ b/drivers/block/zram/zram_drv.c > @@ -33,6 +33,8 @@ > #include <linux/debugfs.h> > #include <linux/cpuhotplug.h> > #include <linux/part_stat.h> > +#include <linux/swap.h> > +#include <linux/frontswap.h> > > #include "zram_drv.h" > > @@ -2170,6 +2172,90 @@ static struct attribute *zram_disk_attrs[] = { > > ATTRIBUTE_GROUPS(zram_disk); > > +static struct zram *zram_swaps[MAX_SWAPFILES]; > +static LIST_HEAD(zram_list); > +static DEFINE_SPINLOCK(zram_list_lock); > + > +static int zram_frontswap_store(unsigned int type, pgoff_t index, > + struct page *page) > +{ > + int err; > + struct zram *zram = zram_swaps[type]; > + > + err = zram_write_page(zram, page, index); > + if (!err) { > + zram_slot_lock(zram, index); > + zram_accessed(zram, index); > + zram_slot_unlock(zram, index); > + } > + > + return err; > +} > + > +static int zram_frontswap_load(unsigned int type, pgoff_t index, > + struct page *page, bool *exclusive) > +{ > + int err; > + struct zram *zram = zram_swaps[type]; > + > + zram_slot_lock(zram, index); > + if (zram_test_flag(zram, index, ZRAM_WB)) { > + zram_slot_lock(zram, index); Looks like zram_slot_unlock should be here instead of zram_slot_lock. > + return -1; > + } > + > + err = zram_read_from_zspool(zram, page, index); > + if (!err) > + zram_accessed(zram, index); > + zram_slot_unlock(zram, index); > + > + return err; > +} > + > +static void zram_frontswap_invalidate_area(unsigned int type) > +{ > + struct zram *zram = zram_swaps[type]; > + > + if (!zram) > + return; > +} It makes sense? Maybe we just leave this function empty? > + > +static void zram_frontswap_init(unsigned int type, struct block_device *bdev) > +{ > + struct zram *zram; > + > + spin_lock(&zram_list_lock); > + list_for_each_entry(zram, &zram_list, list) { > + if (&zram_devops == bdev->bd_disk->fops) { > + zram_swaps[type] = zram; > + break; > + } > + } > + spin_unlock(&zram_list_lock); > +} > + > +static void zram_frontswap_invalidate_page(unsigned int type, pgoff_t offset) > +{ > + struct zram *zram = zram_swaps[type]; > + > + if (!zram_slot_trylock(zram, offset)) { > + atomic64_inc(&zram->stats.miss_free); > + return; > + } > + > + zram_free_page(zram, offset); > + zram_slot_unlock(zram, offset); > +} > + > +static const struct frontswap_ops zram_frontswap_ops = { > + .store = zram_frontswap_store, > + .load = zram_frontswap_load, > + .init = zram_frontswap_init, > + .invalidate_area = zram_frontswap_invalidate_area, > + .invalidate_page = zram_frontswap_invalidate_page, > + .init = zram_frontswap_init > +}; > + > /* > * Allocate and initialize new zram device. the function returns > * '>= 0' device_id upon success, and negative value otherwise. > @@ -2246,6 +2332,10 @@ static int zram_add(void) > > comp_algorithm_set(zram, ZRAM_PRIMARY_COMP, default_compressor); > > + spin_lock(&zram_list_lock); > + list_add(&zram->list, &zram_list); > + spin_unlock(&zram_list_lock); > + > zram_debugfs_register(zram); > pr_info("Added device: %s\n", zram->disk->disk_name); > return device_id; > @@ -2303,6 +2393,11 @@ static int zram_remove(struct zram *zram) > zram_reset_device(zram); > > put_disk(zram->disk); > + > + spin_lock(&zram_list_lock); > + list_del(&zram->list); > + spin_unlock(&zram_list_lock); > + > kfree(zram); > return 0; > } > @@ -2428,6 +2523,9 @@ static int __init zram_init(void) > num_devices--; > } > > + if (frontswap_register_ops(&zram_frontswap_ops)) > + pr_info("Frontswap is not used, which is suboptimal for zram swap.\n"); > + > return 0; > > out_error: > diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h > index ca7a15bd4845..0f52d2da8512 100644 > --- a/drivers/block/zram/zram_drv.h > +++ b/drivers/block/zram/zram_drv.h > @@ -139,5 +139,6 @@ struct zram { > #ifdef CONFIG_ZRAM_MEMORY_TRACKING > struct dentry *debugfs_dir; > #endif > + struct list_head list; > }; > #endif > -- > 2.41.0.255.g8b1d071c50-goog > >
On Tue, Jul 11, 2023 at 10:08:46AM +0000, Alexey Romanov wrote: > Hello, > > On Mon, Jul 10, 2023 at 03:16:58PM -0700, Minchan Kim wrote: > > With frontswap, zram can perform swapout 13% faster, which restores > > its original performance with rw_page. > > > > 200M swapout using MADV_PAGEOUT: > > Before: 4355ms After: 3786ms > > > > Signed-off-by: Minchan Kim <minchan@kernel.org> > > --- > > drivers/block/zram/Kconfig | 1 + > > drivers/block/zram/zram_drv.c | 98 +++++++++++++++++++++++++++++++++++ > > drivers/block/zram/zram_drv.h | 1 + > > 3 files changed, 100 insertions(+) > > > > diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig > > index 0386b7da02aa..a841d6d14c74 100644 > > --- a/drivers/block/zram/Kconfig > > +++ b/drivers/block/zram/Kconfig > > @@ -4,6 +4,7 @@ config ZRAM > > depends on BLOCK && SYSFS && MMU > > depends on CRYPTO_LZO || CRYPTO_ZSTD || CRYPTO_LZ4 || CRYPTO_LZ4HC || CRYPTO_842 > > select ZSMALLOC > > + select FRONTSWAP > > help > > Creates virtual block devices called /dev/zramX (X = 0, 1, ...). > > Pages written to these disks are compressed and stored in memory > > diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c > > index 5d258a28ec43..5e973c982235 100644 > > --- a/drivers/block/zram/zram_drv.c > > +++ b/drivers/block/zram/zram_drv.c > > @@ -33,6 +33,8 @@ > > #include <linux/debugfs.h> > > #include <linux/cpuhotplug.h> > > #include <linux/part_stat.h> > > +#include <linux/swap.h> > > +#include <linux/frontswap.h> > > > > #include "zram_drv.h" > > > > @@ -2170,6 +2172,90 @@ static struct attribute *zram_disk_attrs[] = { > > > > ATTRIBUTE_GROUPS(zram_disk); > > > > +static struct zram *zram_swaps[MAX_SWAPFILES]; > > +static LIST_HEAD(zram_list); > > +static DEFINE_SPINLOCK(zram_list_lock); > > + > > +static int zram_frontswap_store(unsigned int type, pgoff_t index, > > + struct page *page) > > +{ > > + int err; > > + struct zram *zram = zram_swaps[type]; > > + > > + err = zram_write_page(zram, page, index); > > + if (!err) { > > + zram_slot_lock(zram, index); > > + zram_accessed(zram, index); > > + zram_slot_unlock(zram, index); > > + } > > + > > + return err; > > +} > > + > > +static int zram_frontswap_load(unsigned int type, pgoff_t index, > > + struct page *page, bool *exclusive) > > +{ > > + int err; > > + struct zram *zram = zram_swaps[type]; > > + > > + zram_slot_lock(zram, index); > > + if (zram_test_flag(zram, index, ZRAM_WB)) { > > + zram_slot_lock(zram, index); > > Looks like zram_slot_unlock should be here instead of zram_slot_lock. me/ slabs self. > > > + return -1; > > + } > > + > > + err = zram_read_from_zspool(zram, page, index); > > + if (!err) > > + zram_accessed(zram, index); > > + zram_slot_unlock(zram, index); > > + > > + return err; > > +} > > + > > +static void zram_frontswap_invalidate_area(unsigned int type) > > +{ > > + struct zram *zram = zram_swaps[type]; > > + > > + if (!zram) > > + return; > > +} > > It makes sense? Maybe we just leave this function empty? Sorry, it was wrong version from my git tree. I had destroy zram in the case originally but since I decide to drop this patchset, never mind. Thanks for spending time for review, Alexey.
diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig index 0386b7da02aa..a841d6d14c74 100644 --- a/drivers/block/zram/Kconfig +++ b/drivers/block/zram/Kconfig @@ -4,6 +4,7 @@ config ZRAM depends on BLOCK && SYSFS && MMU depends on CRYPTO_LZO || CRYPTO_ZSTD || CRYPTO_LZ4 || CRYPTO_LZ4HC || CRYPTO_842 select ZSMALLOC + select FRONTSWAP help Creates virtual block devices called /dev/zramX (X = 0, 1, ...). Pages written to these disks are compressed and stored in memory diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 5d258a28ec43..5e973c982235 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -33,6 +33,8 @@ #include <linux/debugfs.h> #include <linux/cpuhotplug.h> #include <linux/part_stat.h> +#include <linux/swap.h> +#include <linux/frontswap.h> #include "zram_drv.h" @@ -2170,6 +2172,90 @@ static struct attribute *zram_disk_attrs[] = { ATTRIBUTE_GROUPS(zram_disk); +static struct zram *zram_swaps[MAX_SWAPFILES]; +static LIST_HEAD(zram_list); +static DEFINE_SPINLOCK(zram_list_lock); + +static int zram_frontswap_store(unsigned int type, pgoff_t index, + struct page *page) +{ + int err; + struct zram *zram = zram_swaps[type]; + + err = zram_write_page(zram, page, index); + if (!err) { + zram_slot_lock(zram, index); + zram_accessed(zram, index); + zram_slot_unlock(zram, index); + } + + return err; +} + +static int zram_frontswap_load(unsigned int type, pgoff_t index, + struct page *page, bool *exclusive) +{ + int err; + struct zram *zram = zram_swaps[type]; + + zram_slot_lock(zram, index); + if (zram_test_flag(zram, index, ZRAM_WB)) { + zram_slot_lock(zram, index); + return -1; + } + + err = zram_read_from_zspool(zram, page, index); + if (!err) + zram_accessed(zram, index); + zram_slot_unlock(zram, index); + + return err; +} + +static void zram_frontswap_invalidate_area(unsigned int type) +{ + struct zram *zram = zram_swaps[type]; + + if (!zram) + return; +} + +static void zram_frontswap_init(unsigned int type, struct block_device *bdev) +{ + struct zram *zram; + + spin_lock(&zram_list_lock); + list_for_each_entry(zram, &zram_list, list) { + if (&zram_devops == bdev->bd_disk->fops) { + zram_swaps[type] = zram; + break; + } + } + spin_unlock(&zram_list_lock); +} + +static void zram_frontswap_invalidate_page(unsigned int type, pgoff_t offset) +{ + struct zram *zram = zram_swaps[type]; + + if (!zram_slot_trylock(zram, offset)) { + atomic64_inc(&zram->stats.miss_free); + return; + } + + zram_free_page(zram, offset); + zram_slot_unlock(zram, offset); +} + +static const struct frontswap_ops zram_frontswap_ops = { + .store = zram_frontswap_store, + .load = zram_frontswap_load, + .init = zram_frontswap_init, + .invalidate_area = zram_frontswap_invalidate_area, + .invalidate_page = zram_frontswap_invalidate_page, + .init = zram_frontswap_init +}; + /* * Allocate and initialize new zram device. the function returns * '>= 0' device_id upon success, and negative value otherwise. @@ -2246,6 +2332,10 @@ static int zram_add(void) comp_algorithm_set(zram, ZRAM_PRIMARY_COMP, default_compressor); + spin_lock(&zram_list_lock); + list_add(&zram->list, &zram_list); + spin_unlock(&zram_list_lock); + zram_debugfs_register(zram); pr_info("Added device: %s\n", zram->disk->disk_name); return device_id; @@ -2303,6 +2393,11 @@ static int zram_remove(struct zram *zram) zram_reset_device(zram); put_disk(zram->disk); + + spin_lock(&zram_list_lock); + list_del(&zram->list); + spin_unlock(&zram_list_lock); + kfree(zram); return 0; } @@ -2428,6 +2523,9 @@ static int __init zram_init(void) num_devices--; } + if (frontswap_register_ops(&zram_frontswap_ops)) + pr_info("Frontswap is not used, which is suboptimal for zram swap.\n"); + return 0; out_error: diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h index ca7a15bd4845..0f52d2da8512 100644 --- a/drivers/block/zram/zram_drv.h +++ b/drivers/block/zram/zram_drv.h @@ -139,5 +139,6 @@ struct zram { #ifdef CONFIG_ZRAM_MEMORY_TRACKING struct dentry *debugfs_dir; #endif + struct list_head list; }; #endif
With frontswap, zram can perform swapout 13% faster, which restores its original performance with rw_page. 200M swapout using MADV_PAGEOUT: Before: 4355ms After: 3786ms Signed-off-by: Minchan Kim <minchan@kernel.org> --- drivers/block/zram/Kconfig | 1 + drivers/block/zram/zram_drv.c | 98 +++++++++++++++++++++++++++++++++++ drivers/block/zram/zram_drv.h | 1 + 3 files changed, 100 insertions(+)