From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754671AbaHENR2 (ORCPT ); Tue, 5 Aug 2014 09:17:28 -0400 Received: from mail-pd0-f175.google.com ([209.85.192.175]:49363 "EHLO mail-pd0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753114AbaHENR0 (ORCPT ); Tue, 5 Aug 2014 09:17:26 -0400 Date: Tue, 5 Aug 2014 22:16:15 +0900 From: Sergey Senozhatsky To: Minchan Kim Cc: linux-mm@kvack.org, Jerome Marchand , linux-kernel@vger.kernel.org, juno.choi@lge.com, Sergey Senozhatsky , seungho1.park@lge.com, Luigi Semenzato , Nitin Gupta Subject: Re: [RFC 3/3] zram: limit memory size for zram Message-ID: <20140805131615.GA961@swordfish> References: <1407225723-23754-1-git-send-email-minchan@kernel.org> <1407225723-23754-4-git-send-email-minchan@kernel.org> <20140805094859.GE27993@bbox> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140805094859.GE27993@bbox> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 > > --- > > 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 >