Hello,
On (08/05/14 18:48), Minchan Kim wrote:
> Another idea: we could define void zs_limit_mem(unsinged long nr_pages)
> in zsmalloc and put the limit in zs_pool via new API from zram so that
> zs_malloc could be failed as soon as it exceeds the limit.
>
> In the end, zram doesn't need to call zs_get_total_size_bytes on every
> write. It's more clean and right layer, IMHO.
yes, I think this one is better.
-ss
> On Tue, Aug 05, 2014 at 05:02:03PM +0900, Minchan Kim wrote:
> > I have received a request several time from zram users.
> > They want to limit memory size for zram because zram can consume
> > lot of memory on system without limit so it makes memory management
> > control hard.
> >
> > This patch adds new knob to limit memory of zram.
> >
> > Signed-off-by: Minchan Kim <minc...@kernel.org>
> > ---
> > Documentation/blockdev/zram.txt | 1 +
> > drivers/block/zram/zram_drv.c | 41
> > +++++++++++++++++++++++++++++++++++++++++
> > drivers/block/zram/zram_drv.h | 1 +
> > 3 files changed, 43 insertions(+)
> >
> > diff --git a/Documentation/blockdev/zram.txt
> > b/Documentation/blockdev/zram.txt
> > index d24534bee763..fcb0561dfe2e 100644
> > --- a/Documentation/blockdev/zram.txt
> > +++ b/Documentation/blockdev/zram.txt
> > @@ -96,6 +96,7 @@ size of the disk when not in use so a huge zram is
> > wasteful.
> > compr_data_size
> > mem_used_total
> > mem_used_max
> > + mem_limit
> >
> > 7) Deactivate:
> > swapoff /dev/zram0
> > diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
> > index a4d637b4db7d..47f68bbb2c44 100644
> > --- a/drivers/block/zram/zram_drv.c
> > +++ b/drivers/block/zram/zram_drv.c
> > @@ -137,6 +137,37 @@ static ssize_t max_comp_streams_show(struct device
> > *dev,
> > return scnprintf(buf, PAGE_SIZE, "%d\n", val);
> > }
> >
> > +static ssize_t mem_limit_show(struct device *dev,
> > + struct device_attribute *attr, char *buf)
> > +{
> > + u64 val;
> > + struct zram *zram = dev_to_zram(dev);
> > +
> > + down_read(&zram->init_lock);
> > + val = zram->limit_bytes;
> > + up_read(&zram->init_lock);
> > +
> > + return scnprintf(buf, PAGE_SIZE, "%llu\n", val);
> > +}
> > +
> > +static ssize_t mem_limit_store(struct device *dev,
> > + struct device_attribute *attr, const char *buf, size_t len)
> > +{
> > + u64 limit;
> > + struct zram *zram = dev_to_zram(dev);
> > + int ret;
> > +
> > + ret = kstrtoull(buf, 0, &limit);
> > + if (ret < 0)
> > + return ret;
> > +
> > + down_write(&zram->init_lock);
> > + zram->limit_bytes = limit;
> > + ret = len;
> > + up_write(&zram->init_lock);
> > + return ret;
> > +}
> > +
> > static ssize_t max_comp_streams_store(struct device *dev,
> > struct device_attribute *attr, const char *buf, size_t len)
> > {
> > @@ -511,6 +542,14 @@ static int zram_bvec_write(struct zram *zram, struct
> > bio_vec *bvec, u32 index,
> > ret = -ENOMEM;
> > goto out;
> > }
> > +
> > + if (zram->limit_bytes &&
> > + zs_get_total_size_bytes(meta->mem_pool) >= zram->limit_bytes) {
> > + zs_free(meta->mem_pool, handle);
> > + ret = -ENOMEM;
> > + goto out;
> > + }
> > +
> > cmem = zs_map_object(meta->mem_pool, handle, ZS_MM_WO);
> >
> > if ((clen == PAGE_SIZE) && !is_partial_io(bvec)) {
> > @@ -854,6 +893,7 @@ 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(mem_limit, S_IRUGO, mem_limit_show, mem_limit_store);
> > 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,
> > @@ -883,6 +923,7 @@ static struct attribute *zram_disk_attrs[] = {
> > &dev_attr_compr_data_size.attr,
> > &dev_attr_mem_used_total.attr,
> > &dev_attr_mem_used_max.attr,
> > + &dev_attr_mem_limit.attr,
> > &dev_attr_max_comp_streams.attr,
> > &dev_attr_comp_algorithm.attr,
> > NULL,
> > diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
> > index 7f21c145e317..c0d497ff6efc 100644
> > --- a/drivers/block/zram/zram_drv.h
> > +++ b/drivers/block/zram/zram_drv.h
> > @@ -99,6 +99,7 @@ struct zram {
> > * we can store in a disk.
> > */
> > u64 disksize; /* bytes */
> > + u64 limit_bytes;
> > int max_comp_streams;
> > struct zram_stats stats;
> > char compressor[10];
> > --
> > 2.0.0
>
> --
> Kind regards,
> Minchan Kim
>
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