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author | Sergey Senozhatsky <sergey.senozhatsky@gmail.com> | 2016-05-20 16:59:59 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-05-20 17:58:30 -0700 |
commit | 43209ea2d17aae1540d4e28274e36404f72702f2 (patch) | |
tree | be21fbbabf6fabeb3e1dd4ca2c0684f238458c55 /drivers/block/zram | |
parent | d34f615720d17c49b6779f6fcd5cb7eb82231a38 (diff) | |
download | linux-stable-43209ea2d17aae1540d4e28274e36404f72702f2.tar.gz linux-stable-43209ea2d17aae1540d4e28274e36404f72702f2.tar.bz2 linux-stable-43209ea2d17aae1540d4e28274e36404f72702f2.zip |
zram: remove max_comp_streams internals
Remove the internal part of max_comp_streams interface, since we
switched to per-cpu streams. We will keep RW max_comp_streams attr
around, because:
a) we may (silently) switch back to idle compression streams list and
don't want to disturb user space
b) max_comp_streams attr must wait for the next 'lay off cycle'; we
give user space 2 years to adjust before we remove/downgrade the attr,
and there are already several attrs scheduled for removal in 4.11, so
it's too late for max_comp_streams.
This slightly change a user visible behaviour:
- First, reading from max_comp_stream file now will always return the
number of online CPUs.
- Second, writing to max_comp_stream will not take any effect.
Link: http://lkml.kernel.org/r/20160503165546.25201-1-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/block/zram')
-rw-r--r-- | drivers/block/zram/zcomp.c | 5 | ||||
-rw-r--r-- | drivers/block/zram/zram_drv.c | 45 | ||||
-rw-r--r-- | drivers/block/zram/zram_drv.h | 1 |
3 files changed, 11 insertions, 40 deletions
diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c index bc98d5ed5477..b51a816d766b 100644 --- a/drivers/block/zram/zcomp.c +++ b/drivers/block/zram/zcomp.c @@ -95,11 +95,6 @@ bool zcomp_available_algorithm(const char *comp) return find_backend(comp) != NULL; } -bool zcomp_set_max_streams(struct zcomp *comp, int num_strm) -{ - return true; -} - struct zcomp_strm *zcomp_strm_find(struct zcomp *comp) { return *get_cpu_ptr(comp->stream); diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index f92965c4229b..8fcfbebe79cd 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -304,46 +304,25 @@ static ssize_t mem_used_max_store(struct device *dev, return len; } +/* + * We switched to per-cpu streams and this attr is not needed anymore. + * However, we will keep it around for some time, because: + * a) we may revert per-cpu streams in the future + * b) it's visible to user space and we need to follow our 2 years + * retirement rule; but we already have a number of 'soon to be + * altered' attrs, so max_comp_streams need to wait for the next + * layoff cycle. + */ static ssize_t max_comp_streams_show(struct device *dev, struct device_attribute *attr, char *buf) { - int val; - struct zram *zram = dev_to_zram(dev); - - down_read(&zram->init_lock); - val = zram->max_comp_streams; - up_read(&zram->init_lock); - - return scnprintf(buf, PAGE_SIZE, "%d\n", val); + return scnprintf(buf, PAGE_SIZE, "%d\n", num_online_cpus()); } static ssize_t max_comp_streams_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { - int num; - struct zram *zram = dev_to_zram(dev); - int ret; - - ret = kstrtoint(buf, 0, &num); - if (ret < 0) - return ret; - if (num < 1) - return -EINVAL; - - down_write(&zram->init_lock); - if (init_done(zram)) { - if (!zcomp_set_max_streams(zram->comp, num)) { - pr_info("Cannot change max compression streams\n"); - ret = -EINVAL; - goto out; - } - } - - zram->max_comp_streams = num; - ret = len; -out: - up_write(&zram->init_lock); - return ret; + return len; } static ssize_t comp_algorithm_show(struct device *dev, @@ -1035,7 +1014,6 @@ static void zram_reset_device(struct zram *zram) /* Reset stats */ memset(&zram->stats, 0, sizeof(zram->stats)); zram->disksize = 0; - zram->max_comp_streams = 1; set_capacity(zram->disk, 0); part_stat_set_all(&zram->disk->part0, 0); @@ -1299,7 +1277,6 @@ static int zram_add(void) } strlcpy(zram->compressor, default_compressor, sizeof(zram->compressor)); zram->meta = NULL; - zram->max_comp_streams = 1; pr_info("Added device: %s\n", zram->disk->disk_name); return device_id; diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h index 8e92339686d7..06b1636f4722 100644 --- a/drivers/block/zram/zram_drv.h +++ b/drivers/block/zram/zram_drv.h @@ -102,7 +102,6 @@ struct zram { * the number of pages zram can consume for storing compressed data */ unsigned long limit_pages; - int max_comp_streams; struct zram_stats stats; atomic_t refcount; /* refcount for zram_meta */ |