RE: [f2fs-dev] [PATCH V2] f2fs: check all ones or zeros bitmap with bitops for better mount performance
Hi Lee,
> -Original Message-
> From: 이창만 [mailto:cm224@samsung.com]
> Sent: Monday, October 28, 2013 10:20 AM
> To: 'Chao Yu'; jaegeuk@samsung.com
> Cc: linux-fsde...@vger.kernel.org; '谭姝'; linux-kernel@vger.kernel.org;
> linux-f2fs-de...@lists.sourceforge.net
> Subject: RE: [f2fs-dev] [PATCH V2] f2fs: check all ones or zeros bitmap with
> bitops for better mount performance
>
> To check whether bitmap are all zeros or all ones, I think memcmp is more
> neat.
> But I don't know exactly performance gap between memcmp and
> find_next_bit.
With the result of my test, find_next_bit takes less time than memcmp.
If we could use {test, set, clear}_bit_le intead of f2fs_{test, set,
clear}_bit, the following patch
could be used for better performance.
This one is better than the V2 patch for performance with mixed bitmap in my
test.
diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index 7f94d78..32153eb
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -544,7 +544,8 @@ static inline void check_block_count(struct f2fs_sb_info
*sbi,
struct f2fs_sm_info *sm_info = SM_I(sbi);
unsigned int end_segno = sm_info->segment_count - 1;
int valid_blocks = 0;
- int i;
+ int i, cur_pos = 0, next_pos;
+ bool is_valid;
/* check segment usage */
BUG_ON(GET_SIT_VBLOCKS(raw_sit) > sbi->blocks_per_seg);
@@ -553,9 +554,21 @@ static inline void check_block_count(struct f2fs_sb_info
*sbi,
BUG_ON(segno > end_segno);
/* check bitmap with valid block count */
- for (i = 0; i < sbi->blocks_per_seg; i++)
- if (f2fs_test_bit(i, raw_sit->valid_map))
- valid_blocks++;
+ cur_pos = 0;
+ is_valid = test_bit_le(0, raw_sit->valid_map) ? true : false;
+ do {
+ if (is_valid) {
+ next_pos = find_next_zero_bit_le(&raw_sit->valid_map,
+ sbi->blocks_per_seg,
+ cur_pos);
+ valid_blocks += next_pos - cur_pos;
+ } else
+ next_pos = find_next_bit_le(&raw_sit->valid_map,
+ sbi->blocks_per_seg,
+ cur_pos);
+ cur_pos = next_pos;
+ is_valid = !is_valid;
+ } while (cur_pos < sbi->blocks_per_seg);
BUG_ON(GET_SIT_VBLOCKS(raw_sit) != valid_blocks);
}
>
>
> -Original Message-
> From: Chao Yu [mailto:chao2...@samsung.com]
> Sent: Thursday, October 24, 2013 5:21 PM
> To: jaegeuk@samsung.com
> Cc: linux-fsde...@vger.kernel.org; '谭姝'; linux-kernel@vger.kernel.org;
> linux-f2fs-de...@lists.sourceforge.net
> Subject: [f2fs-dev] [PATCH V2] f2fs: check all ones or zeros bitmap with
> bitops
> for better mount performance
>
> Previously, check_block_count check valid_map with bit data type in common
> scenario that sit has all ones or zeros bitmap, it makes low mount
> performance.
> So let's check the special bitmap with integer data type instead of the bit
> one.
>
> v2:
> use find_next_bit_le/find_next_zero_bit_le for better performance and
> readable as Jaegeuk suggested.
>
> Suggested-by: Jaegeuk Kim
> Signed-off-by: Tan Shu
> Signed-off-by: Yu Chao
> ---
> fs/f2fs/segment.h | 17 +
> 1 file changed, 17 insertions(+)
>
> diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h index 7f94d78..d25b6af
> 100644
> --- a/fs/f2fs/segment.h
> +++ b/fs/f2fs/segment.h
> @@ -552,6 +552,23 @@ static inline void check_block_count(struct
> f2fs_sb_info *sbi,
> /* check boundary of a given segment number */
> BUG_ON(segno > end_segno);
>
> + /* check all ones or zeros valid_map */
> + if (GET_SIT_VBLOCKS(raw_sit) == 0) {
> + int pos = find_next_bit_le(&raw_sit->valid_map,
> + sbi->blocks_per_seg,
> + 0);
> + if (pos != sbi->blocks_per_seg)
> + BUG();
> + return;
> + } else if (GET_SIT_VBLOCKS(raw_sit) == sbi->blocks_per_seg) {
> + int pos = find_next_zero_bit_le(&raw_sit->valid_map,
> + sbi->blocks_per_seg,
> + 0);
> + if (pos != sbi->blocks_per_seg)
> + BUG();
> + return;
> + }
> +
> /* check bitmap with valid block count */
> for (i = 0; i < sbi->blocks_per_seg; i++)
> if (f2fs_test_bit(i, raw_sit->valid_map))
> --
> 1.7.9.5
>
>
Re: [f2fs-dev] [PATCH V2] f2fs: check all ones or zeros bitmap with bitops for better mount performance
On 10/28/2013 10:19 AM, 이창만 wrote:
> To check whether bitmap are all zeros or all ones, I think memcmp is more
> neat.
> But I don't know exactly performance gap between memcmp and find_next_bit.
According to my understanding,
memcmp: one by one search,
find_next_bit: binary search.
Regards,
Gu
>
>
> -Original Message-
> From: Chao Yu [mailto:chao2...@samsung.com]
> Sent: Thursday, October 24, 2013 5:21 PM
> To: jaegeuk@samsung.com
> Cc: linux-fsde...@vger.kernel.org; '谭姝'; linux-kernel@vger.kernel.org;
> linux-f2fs-de...@lists.sourceforge.net
> Subject: [f2fs-dev] [PATCH V2] f2fs: check all ones or zeros bitmap with
> bitops for better mount performance
>
> Previously, check_block_count check valid_map with bit data type in common
> scenario that sit has all ones or zeros bitmap, it makes low mount
> performance.
> So let's check the special bitmap with integer data type instead of the bit
> one.
>
> v2:
> use find_next_bit_le/find_next_zero_bit_le for better performance and
> readable as Jaegeuk suggested.
>
> Suggested-by: Jaegeuk Kim
> Signed-off-by: Tan Shu
> Signed-off-by: Yu Chao
> ---
> fs/f2fs/segment.h | 17 +
> 1 file changed, 17 insertions(+)
>
> diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h index 7f94d78..d25b6af
> 100644
> --- a/fs/f2fs/segment.h
> +++ b/fs/f2fs/segment.h
> @@ -552,6 +552,23 @@ static inline void check_block_count(struct f2fs_sb_info
> *sbi,
> /* check boundary of a given segment number */
> BUG_ON(segno > end_segno);
>
> + /* check all ones or zeros valid_map */
> + if (GET_SIT_VBLOCKS(raw_sit) == 0) {
> + int pos = find_next_bit_le(&raw_sit->valid_map,
> + sbi->blocks_per_seg,
> + 0);
> + if (pos != sbi->blocks_per_seg)
> + BUG();
> + return;
> + } else if (GET_SIT_VBLOCKS(raw_sit) == sbi->blocks_per_seg) {
> + int pos = find_next_zero_bit_le(&raw_sit->valid_map,
> + sbi->blocks_per_seg,
> + 0);
> + if (pos != sbi->blocks_per_seg)
> + BUG();
> + return;
> + }
> +
> /* check bitmap with valid block count */
> for (i = 0; i < sbi->blocks_per_seg; i++)
> if (f2fs_test_bit(i, raw_sit->valid_map))
> --
> 1.7.9.5
>
>
> --
> October Webinars: Code for Performance
> Free Intel webinars can help you accelerate application performance.
> Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from
> the latest Intel processors and coprocessors. See abstracts and register >
> http://pubads.g.doubleclick.net/gampad/clk?id=60135991&iu=/4140/ostg.clktrk
> ___
> Linux-f2fs-devel mailing list
> linux-f2fs-de...@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
>
> --
> 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/
>
--
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: [f2fs-dev] [PATCH V2] f2fs: check all ones or zeros bitmap with bitops for better mount performance
To check whether bitmap are all zeros or all ones, I think memcmp is more neat.
But I don't know exactly performance gap between memcmp and find_next_bit.
-Original Message-
From: Chao Yu [mailto:chao2...@samsung.com]
Sent: Thursday, October 24, 2013 5:21 PM
To: jaegeuk@samsung.com
Cc: linux-fsde...@vger.kernel.org; '谭姝'; linux-kernel@vger.kernel.org;
linux-f2fs-de...@lists.sourceforge.net
Subject: [f2fs-dev] [PATCH V2] f2fs: check all ones or zeros bitmap with bitops
for better mount performance
Previously, check_block_count check valid_map with bit data type in common
scenario that sit has all ones or zeros bitmap, it makes low mount performance.
So let's check the special bitmap with integer data type instead of the bit one.
v2:
use find_next_bit_le/find_next_zero_bit_le for better performance and
readable as Jaegeuk suggested.
Suggested-by: Jaegeuk Kim
Signed-off-by: Tan Shu
Signed-off-by: Yu Chao
---
fs/f2fs/segment.h | 17 +
1 file changed, 17 insertions(+)
diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h index 7f94d78..d25b6af 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -552,6 +552,23 @@ static inline void check_block_count(struct f2fs_sb_info
*sbi,
/* check boundary of a given segment number */
BUG_ON(segno > end_segno);
+ /* check all ones or zeros valid_map */
+ if (GET_SIT_VBLOCKS(raw_sit) == 0) {
+ int pos = find_next_bit_le(&raw_sit->valid_map,
+ sbi->blocks_per_seg,
+ 0);
+ if (pos != sbi->blocks_per_seg)
+ BUG();
+ return;
+ } else if (GET_SIT_VBLOCKS(raw_sit) == sbi->blocks_per_seg) {
+ int pos = find_next_zero_bit_le(&raw_sit->valid_map,
+ sbi->blocks_per_seg,
+ 0);
+ if (pos != sbi->blocks_per_seg)
+ BUG();
+ return;
+ }
+
/* check bitmap with valid block count */
for (i = 0; i < sbi->blocks_per_seg; i++)
if (f2fs_test_bit(i, raw_sit->valid_map))
--
1.7.9.5
--
October Webinars: Code for Performance
Free Intel webinars can help you accelerate application performance.
Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from
the latest Intel processors and coprocessors. See abstracts and register >
http://pubads.g.doubleclick.net/gampad/clk?id=60135991&iu=/4140/ostg.clktrk
___
Linux-f2fs-devel mailing list
linux-f2fs-de...@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
--
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: [f2fs-dev] [PATCH V2] f2fs: check all ones or zeros bitmap with bitops for better mount performance
Hi Gu,
> -Original Message-
> From: Gu Zheng [mailto:guz.f...@cn.fujitsu.com]
> Sent: Thursday, October 24, 2013 6:04 PM
> To: Chao Yu
> Cc: jaegeuk@samsung.com; linux-fsde...@vger.kernel.org;
> linux-kernel@vger.kernel.org; linux-f2fs-de...@lists.sourceforge.net; '谭姝'
> Subject: Re: [f2fs-dev] [PATCH V2] f2fs: check all ones or zeros bitmap with
> bitops for better mount performance
>
> Hi Yu,
> On 10/24/2013 04:21 PM, Chao Yu wrote:
>
> > Previously, check_block_count check valid_map with bit data type in common
> scenario that sit has all ones or zeros bitmap, it makes low mount
> performance.
> > So let's check the special bitmap with integer data type instead of the bit
> > one.
> >
> > v2:
> > use find_next_bit_le/find_next_zero_bit_le for better performance and
> readable as Jaegeuk suggested.
>
> If so, how about using find_first_{zero_}bit_le instead? It's more neat.
It seems more neat. I will take it, thanks.
>
> Regards,
> Gu
>
> >
> > Suggested-by: Jaegeuk Kim
> > Signed-off-by: Tan Shu
> > Signed-off-by: Yu Chao
> > ---
> > fs/f2fs/segment.h | 17 +
> > 1 file changed, 17 insertions(+)
> >
> > diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h index
> > 7f94d78..d25b6af 100644
> > --- a/fs/f2fs/segment.h
> > +++ b/fs/f2fs/segment.h
> > @@ -552,6 +552,23 @@ static inline void check_block_count(struct
> f2fs_sb_info *sbi,
> > /* check boundary of a given segment number */
> > BUG_ON(segno > end_segno);
> >
> > + /* check all ones or zeros valid_map */
> > + if (GET_SIT_VBLOCKS(raw_sit) == 0) {
> > + int pos = find_next_bit_le(&raw_sit->valid_map,
> > + sbi->blocks_per_seg,
> > + 0);
> > + if (pos != sbi->blocks_per_seg)
> > + BUG();
> > + return;
> > + } else if (GET_SIT_VBLOCKS(raw_sit) == sbi->blocks_per_seg) {
> > + int pos = find_next_zero_bit_le(&raw_sit->valid_map,
> > + sbi->blocks_per_seg,
> > + 0);
> > + if (pos != sbi->blocks_per_seg)
> > + BUG();
> > + return;
> > + }
> > +
> > /* check bitmap with valid block count */
> > for (i = 0; i < sbi->blocks_per_seg; i++)
> > if (f2fs_test_bit(i, raw_sit->valid_map))
--
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: [f2fs-dev] [PATCH V2] f2fs: check all ones or zeros bitmap with bitops for better mount performance
Hi Yu,
On 10/24/2013 04:21 PM, Chao Yu wrote:
> Previously, check_block_count check valid_map with bit data type in common
> scenario that sit has all ones or zeros bitmap, it makes low mount
> performance.
> So let's check the special bitmap with integer data type instead of the bit
> one.
>
> v2:
> use find_next_bit_le/find_next_zero_bit_le for better performance and
> readable as Jaegeuk suggested.
If so, how about using find_first_{zero_}bit_le instead? It's more neat.
Regards,
Gu
>
> Suggested-by: Jaegeuk Kim
> Signed-off-by: Tan Shu
> Signed-off-by: Yu Chao
> ---
> fs/f2fs/segment.h | 17 +
> 1 file changed, 17 insertions(+)
>
> diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
> index 7f94d78..d25b6af 100644
> --- a/fs/f2fs/segment.h
> +++ b/fs/f2fs/segment.h
> @@ -552,6 +552,23 @@ static inline void check_block_count(struct f2fs_sb_info
> *sbi,
> /* check boundary of a given segment number */
> BUG_ON(segno > end_segno);
>
> + /* check all ones or zeros valid_map */
> + if (GET_SIT_VBLOCKS(raw_sit) == 0) {
> + int pos = find_next_bit_le(&raw_sit->valid_map,
> + sbi->blocks_per_seg,
> + 0);
> + if (pos != sbi->blocks_per_seg)
> + BUG();
> + return;
> + } else if (GET_SIT_VBLOCKS(raw_sit) == sbi->blocks_per_seg) {
> + int pos = find_next_zero_bit_le(&raw_sit->valid_map,
> + sbi->blocks_per_seg,
> + 0);
> + if (pos != sbi->blocks_per_seg)
> + BUG();
> + return;
> + }
> +
> /* check bitmap with valid block count */
> for (i = 0; i < sbi->blocks_per_seg; i++)
> if (f2fs_test_bit(i, raw_sit->valid_map))
--
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/
