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| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2024-09-06 16:14:45 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2024-09-06 16:51:08 +0200 |
| commit | 68d20eb60efbdc80662efedeb088353e9c4aa17f (patch) | |
| tree | 008eb7b4c8374097a2766b8f8f792f8901bc2e8d /drivers/block | |
| parent | zram: Remove ZRAM_LOCK (diff) | |
| download | linux-68d20eb60efbdc80662efedeb088353e9c4aa17f.tar.xz linux-68d20eb60efbdc80662efedeb088353e9c4aa17f.zip | |
zram: Shrink zram_table_entry::flags.
The zram_table_entry::flags member is of type long and uses 8 bytes on a
64bit architecture. With a PAGE_SIZE of 256KiB we have PAGE_SHIFT of 18
which in turn leads to __NR_ZRAM_PAGEFLAGS = 27. This still fits in an
ordinary integer.
By reducing the size of `flags' to four bytes, the size of the struct
goes back to 16 bytes. The padding between the lock and ac_time (if
enabled) is also gone.
Make zram_table_entry::flags an unsigned int and update the build test
to reflect the change.
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/20240906141520.730009-4-bigeasy@linutronix.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/zram/zram_drv.c | 3 | ||||
| -rw-r--r-- | drivers/block/zram/zram_drv.h | 2 |
2 files changed, 3 insertions, 2 deletions
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 60946a9a7bc4..84cd62efac0f 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -2404,9 +2404,10 @@ static void destroy_devices(void) static int __init zram_init(void) { + struct zram_table_entry zram_te; int ret; - BUILD_BUG_ON(__NR_ZRAM_PAGEFLAGS > BITS_PER_LONG); + BUILD_BUG_ON(__NR_ZRAM_PAGEFLAGS > sizeof(zram_te.flags) * 8); ret = cpuhp_setup_state_multi(CPUHP_ZCOMP_PREPARE, "block/zram:prepare", zcomp_cpu_up_prepare, zcomp_cpu_dead); diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h index 262fa960a078..531cefc66668 100644 --- a/drivers/block/zram/zram_drv.h +++ b/drivers/block/zram/zram_drv.h @@ -66,7 +66,7 @@ struct zram_table_entry { unsigned long handle; unsigned long element; }; - unsigned long flags; + unsigned int flags; spinlock_t lock; #ifdef CONFIG_ZRAM_TRACK_ENTRY_ACTIME ktime_t ac_time; |