Re: [PATCH v5 0/3] zram: add rw_page implementation for zram and clean up unnecessary parameter
On Thu, Oct 23, 2014 at 08:20:22AM +0900, Minchan Kim wrote: Thank you for reply. Your advice was a big help! I will send the fixed version. > Hey Karam, > > You could keep Acked-by/Reviewed-by gotten from me and Jerome > in old versions if new version isn't changed heavily. > It's credit of them and at least, you should respect it. :) > > Please Cc Andrew for zram patches because he merges the patche > into his tree (ie, mmotm). > Oops but get_maintainer.pl -f drivers/block/zram doesn't say it. :( > > Anyway, Thansk for nice work! > > On Wed, Oct 22, 2014 at 05:44:46PM +0900, karam....@lge.com wrote: > > From: "karam.lee" > > > > Recently rw_page block device operation has been added. > > This patchset implements rw_page operation for zram block device > > and does some clean-up. > > > > Patches 1~2 are for clean-up. > > Patch 3 is for implementation of rw_page operation. > > With the rw_page operation, zram can do I/O without allocating a BIO. > > It make zram can save time and memory. > > > > karam.lee (3): > > zram: remove bio parameter from zram_bvec_rw(). > > zram: change parameter from vaild_io_request() > > zram: implement rw_page operation of zram > > Acked-by: Minchan Kim > > -- > Kind regards, > Minchan Kim -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v5 0/3] zram: add rw_page implementation for zram and clean up unnecessary parameter
On Thu, Oct 23, 2014 at 08:20:22AM +0900, Minchan Kim wrote: Thank you for reply. Your advice was a big help! I will send the fixed version. Hey Karam, You could keep Acked-by/Reviewed-by gotten from me and Jerome in old versions if new version isn't changed heavily. It's credit of them and at least, you should respect it. :) Please Cc Andrew for zram patches because he merges the patche into his tree (ie, mmotm). Oops but get_maintainer.pl -f drivers/block/zram doesn't say it. :( Anyway, Thansk for nice work! On Wed, Oct 22, 2014 at 05:44:46PM +0900, karam@lge.com wrote: From: karam.lee karam@lge.com Recently rw_page block device operation has been added. This patchset implements rw_page operation for zram block device and does some clean-up. Patches 1~2 are for clean-up. Patch 3 is for implementation of rw_page operation. With the rw_page operation, zram can do I/O without allocating a BIO. It make zram can save time and memory. karam.lee (3): zram: remove bio parameter from zram_bvec_rw(). zram: change parameter from vaild_io_request() zram: implement rw_page operation of zram Acked-by: Minchan Kim minc...@kernel.org -- Kind regards, Minchan Kim -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v3 3/3] zram: implement rw_page operation of zram
On Tue, Oct 21, 2014 at 03:57:29PM +0200, Jerome Marchand wrote:
> On 10/21/2014 09:27 AM, karam@lge.com wrote:
> > From: "karam.lee"
> >
> > This patch implements rw_page operation for zram block device.
> >
> > I implemented the feature in zram and tested it.
> > Test bed was the G2, LG electronic mobile device, whtich has msm8974
> > processor and 2GB memory.
> > With a memory allocation test program consuming memory, the system
> > generates swap.
> > And operating time of swap_write_page() was measured.
> >
> > --
> > | | operating time | improvement |
> > | | (20 runs average) | |
> > --
> > |with patch |1061.15 us |+2.4%|
> > --
> > |without patch|1087.35 us | |
> > --
> >
> > Each test(with paged_io,with BIO) result set shows normal distribution
> > and has equal variance.
> > I mean the two values are valid result to compare.
> > I can say operation with paged I/O(without BIO) is faster 2.4% with
> > confidence level 95%.
> >
> > Signed-off-by: karam.lee
> > ---
> > drivers/block/zram/zram_drv.c | 38 ++
> > 1 file changed, 38 insertions(+)
> >
> > diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
> > index 4565fdc..696f0b5 100644
> > --- a/drivers/block/zram/zram_drv.c
> > +++ b/drivers/block/zram/zram_drv.c
> > @@ -810,8 +810,46 @@ static void zram_slot_free_notify(struct block_device
> > *bdev,
> > atomic64_inc(>stats.notify_free);
> > }
> >
> > +static int zram_rw_page(struct block_device *bdev, sector_t sector,
> > + struct page *page, int rw)
> > +{
> > + int offset, ret = 1;
>
> Small nitpick, but why do you initialize ret to 1? It doesn't seem to be
> ever used (nor is 1 a valid return value AFAICT).
>
> It otherwise looks good.
>
> Acked-by: Jerome Marchand
>
Thank you for reply. I agree with your opinion.
It was my mistake to initialize ret to 1.
I will resend the fixed version.
> > + u32 index;
> > + struct zram *zram;
> > + struct bio_vec bv;
> > +
> > + zram = bdev->bd_disk->private_data;
> > + if (!valid_io_request(zram, sector, PAGE_SIZE)) {
> > + atomic64_inc(>stats.invalid_io);
> > + ret = -EINVAL;
> > + goto out;
> > + }
> > +
> > + down_read(>init_lock);
> > + if (unlikely(!init_done(zram))) {
> > + ret = -ENOMEM;
> > + goto out_unlock;
> > + }
> > +
> > + index = sector >> SECTORS_PER_PAGE_SHIFT;
> > + offset = sector & (SECTORS_PER_PAGE - 1) << SECTOR_SHIFT;
> > +
> > + bv.bv_page = page;
> > + bv.bv_len = PAGE_SIZE;
> > + bv.bv_offset = 0;
> > +
> > + ret = zram_bvec_rw(zram, , index, offset, rw);
> > +
> > +out_unlock:
> > + up_read(>init_lock);
> > +out:
> > + page_endio(page, rw, ret);
> > + return ret;
> > +}
> > +
> > static const struct block_device_operations zram_devops = {
> > .swap_slot_free_notify = zram_slot_free_notify,
> > + .rw_page = zram_rw_page,
> > .owner = THIS_MODULE
> > };
> >
> >
>
>
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Re: [PATCH v3 3/3] zram: implement rw_page operation of zram
On Tue, Oct 21, 2014 at 03:57:29PM +0200, Jerome Marchand wrote:
On 10/21/2014 09:27 AM, karam@lge.com wrote:
From: karam.lee karam@lge.com
This patch implements rw_page operation for zram block device.
I implemented the feature in zram and tested it.
Test bed was the G2, LG electronic mobile device, whtich has msm8974
processor and 2GB memory.
With a memory allocation test program consuming memory, the system
generates swap.
And operating time of swap_write_page() was measured.
--
| | operating time | improvement |
| | (20 runs average) | |
--
|with patch |1061.15 us |+2.4%|
--
|without patch|1087.35 us | |
--
Each test(with paged_io,with BIO) result set shows normal distribution
and has equal variance.
I mean the two values are valid result to compare.
I can say operation with paged I/O(without BIO) is faster 2.4% with
confidence level 95%.
Signed-off-by: karam.lee karam@lge.com
---
drivers/block/zram/zram_drv.c | 38 ++
1 file changed, 38 insertions(+)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 4565fdc..696f0b5 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -810,8 +810,46 @@ static void zram_slot_free_notify(struct block_device
*bdev,
atomic64_inc(zram-stats.notify_free);
}
+static int zram_rw_page(struct block_device *bdev, sector_t sector,
+ struct page *page, int rw)
+{
+ int offset, ret = 1;
Small nitpick, but why do you initialize ret to 1? It doesn't seem to be
ever used (nor is 1 a valid return value AFAICT).
It otherwise looks good.
Acked-by: Jerome Marchand jmarc...@redhat.com
Thank you for reply. I agree with your opinion.
It was my mistake to initialize ret to 1.
I will resend the fixed version.
+ u32 index;
+ struct zram *zram;
+ struct bio_vec bv;
+
+ zram = bdev-bd_disk-private_data;
+ if (!valid_io_request(zram, sector, PAGE_SIZE)) {
+ atomic64_inc(zram-stats.invalid_io);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ down_read(zram-init_lock);
+ if (unlikely(!init_done(zram))) {
+ ret = -ENOMEM;
+ goto out_unlock;
+ }
+
+ index = sector SECTORS_PER_PAGE_SHIFT;
+ offset = sector (SECTORS_PER_PAGE - 1) SECTOR_SHIFT;
+
+ bv.bv_page = page;
+ bv.bv_len = PAGE_SIZE;
+ bv.bv_offset = 0;
+
+ ret = zram_bvec_rw(zram, bv, index, offset, rw);
+
+out_unlock:
+ up_read(zram-init_lock);
+out:
+ page_endio(page, rw, ret);
+ return ret;
+}
+
static const struct block_device_operations zram_devops = {
.swap_slot_free_notify = zram_slot_free_notify,
+ .rw_page = zram_rw_page,
.owner = THIS_MODULE
};
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