On Tue, Aug 05, 2014 at 05:02:02PM +0900, Minchan Kim wrote:
> Normally, zram user can get maximum memory zsmalloc consumed via
> polling mem_used_total with sysfs in userspace.
>
> But it has a critical problem because user can miss peak memory
> usage during update interval so that gap between them could be
> huge when memory pressure is really heavy.
>
> This patch adds new API zs_get_max_size_bytes in zsmalloc so
> user(ex, zram) doesn't need to poll in short interval to get
> exact value.
>
> User can just see max memory usage once his test workload is
> done. It's pretty handy and accurate.
>
> Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
> ---
> Documentation/blockdev/zram.txt | 1 +
> drivers/block/zram/zram_drv.c | 17 +++++++++++++++++
> include/linux/zsmalloc.h | 1 +
> mm/zsmalloc.c | 20 ++++++++++++++++++++
> 4 files changed, 39 insertions(+)
>
> diff --git a/Documentation/blockdev/zram.txt b/Documentation/blockdev/zram.txt
> index 0595c3f56ccf..d24534bee763 100644
> --- a/Documentation/blockdev/zram.txt
> +++ b/Documentation/blockdev/zram.txt
> @@ -95,6 +95,7 @@ size of the disk when not in use so a huge zram is wasteful.
> orig_data_size
> compr_data_size
> mem_used_total
> + mem_used_max
>
> 7) Deactivate:
> swapoff /dev/zram0
> diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
> index 36e54be402df..a4d637b4db7d 100644
> --- a/drivers/block/zram/zram_drv.c
> +++ b/drivers/block/zram/zram_drv.c
> @@ -109,6 +109,21 @@ static ssize_t mem_used_total_show(struct device *dev,
> return scnprintf(buf, PAGE_SIZE, "%llu\n", val);
> }
>
> +static ssize_t mem_used_max_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + u64 val = 0;
> + struct zram *zram = dev_to_zram(dev);
> + struct zram_meta *meta = zram->meta;
> +
> + down_read(&zram->init_lock);
> + if (init_done(zram))
> + val = zs_get_max_size_bytes(meta->mem_pool);
> + up_read(&zram->init_lock);
> +
> + return scnprintf(buf, PAGE_SIZE, "%llu\n", val);
> +}
> +
> static ssize_t max_comp_streams_show(struct device *dev,
> struct device_attribute *attr, char *buf)
> {
> @@ -838,6 +853,7 @@ static DEVICE_ATTR(initstate, S_IRUGO, initstate_show, NULL);
> static DEVICE_ATTR(reset, S_IWUSR, NULL, reset_store);
> static DEVICE_ATTR(orig_data_size, S_IRUGO, orig_data_size_show, NULL);
> static DEVICE_ATTR(mem_used_total, S_IRUGO, mem_used_total_show, NULL);
> +static DEVICE_ATTR(mem_used_max, S_IRUGO, mem_used_max_show, NULL);
> static DEVICE_ATTR(max_comp_streams, S_IRUGO | S_IWUSR,
> max_comp_streams_show, max_comp_streams_store);
> static DEVICE_ATTR(comp_algorithm, S_IRUGO | S_IWUSR,
> @@ -866,6 +882,7 @@ static struct attribute *zram_disk_attrs[] = {
> &dev_attr_orig_data_size.attr,
> &dev_attr_compr_data_size.attr,
> &dev_attr_mem_used_total.attr,
> + &dev_attr_mem_used_max.attr,
> &dev_attr_max_comp_streams.attr,
> &dev_attr_comp_algorithm.attr,
> NULL,
> diff --git a/include/linux/zsmalloc.h b/include/linux/zsmalloc.h
> index e44d634e7fb7..fb087ca06a88 100644
> --- a/include/linux/zsmalloc.h
> +++ b/include/linux/zsmalloc.h
> @@ -47,5 +47,6 @@ void *zs_map_object(struct zs_pool *pool, unsigned long handle,
> void zs_unmap_object(struct zs_pool *pool, unsigned long handle);
>
> u64 zs_get_total_size_bytes(struct zs_pool *pool);
> +u64 zs_get_max_size_bytes(struct zs_pool *pool);
>
> #endif
> diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
> index a6089bd26621..3b5be076268a 100644
> --- a/mm/zsmalloc.c
> +++ b/mm/zsmalloc.c
> @@ -219,6 +219,7 @@ struct zs_pool {
>
> gfp_t flags; /* allocation flags used when growing pool */
> unsigned long pages_allocated;
> + unsigned long max_pages_allocated;
Same here with atomic.
Seth
> };
>
> /*
> @@ -946,6 +947,8 @@ unsigned long zs_malloc(struct zs_pool *pool, size_t size)
> set_zspage_mapping(first_page, class->index, ZS_EMPTY);
> spin_lock(&pool->stat_lock);
> pool->pages_allocated += class->pages_per_zspage;
> + if (pool->max_pages_allocated < pool->pages_allocated)
> + pool->max_pages_allocated = pool->pages_allocated;
> spin_unlock(&pool->stat_lock);
> spin_lock(&class->lock);
> }
> @@ -1101,6 +1104,9 @@ void zs_unmap_object(struct zs_pool *pool, unsigned long handle)
> }
> EXPORT_SYMBOL_GPL(zs_unmap_object);
>
> +/*
> + * Reports current memory usage consumed by zs_malloc
> + */
> u64 zs_get_total_size_bytes(struct zs_pool *pool)
> {
> u64 npages;
> @@ -1112,6 +1118,20 @@ u64 zs_get_total_size_bytes(struct zs_pool *pool)
> }
> EXPORT_SYMBOL_GPL(zs_get_total_size_bytes);
>
> +/*
> + * Reports maximum memory usage zs_malloc have consumed
> + */
> +u64 zs_get_max_size_bytes(struct zs_pool *pool)
> +{
> + u64 npages;
> +
> + spin_lock(&pool->stat_lock);
> + npages = pool->max_pages_allocated;
> + spin_unlock(&pool->stat_lock);
> + return npages << PAGE_SHIFT;
> +}
> +EXPORT_SYMBOL_GPL(zs_get_max_size_bytes);
> +
> module_init(zs_init);
> module_exit(zs_exit);
>
> --
> 2.0.0
>
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