* [f2fs-dev] [PATCH] f2fs: readahead node block in F2FS_GET_BLOCK_PRECACHE mode [not found] <CGME20250917055237epcas1p2faa1b3d6555ffc5179c700e7a2afd448@epcas1p2.samsung.com> @ 2025-09-17 5:52 ` Yunji Kang 0 siblings, 0 replies; 8+ messages in thread From: Yunji Kang @ 2025-09-17 5:52 UTC (permalink / raw) To: jaegeuk, chao; +Cc: Sungjong Seo, linux-kernel, linux-f2fs-devel In f2fs_precache_extents(), For large files, It requires reading many node blocks. Instead of reading each node block with synchronous I/O, this patch applies readahead so that node blocks can be fetched in advance. It reduces the overhead of repeated sync reads and improves efficiency when precaching extents of large files. I created a file with the same largest extent and executed the test. For this experiment, I set the file's largest extent with an offset of 0 and a size of 1GB. I configured the remaining area with 100MB extents. 5GB test file: dd if=/dev/urandom of=test1 bs=1m count=5120 cp test1 test2 fsync test1 dd if=test1 of=test2 bs=1m skip=1024 seek=1024 count=100 conv=notrunc dd if=test1 of=test2 bs=1m skip=1224 seek=1224 count=100 conv=notrunc ... dd if=test1 of=test2 bs=1m skip=5024 seek=5024 count=100 conv=notrunc reboot I also created 10GB and 20GB files with large extents using the same method. ioctl(F2FS_IOC_PRECACHE_EXTENTS) test results are as follows: +-----------+---------+---------+-----------+ | File size | Before | After | Reduction | +-----------+---------+---------+-----------+ | 5GB | 101.8ms | 72.1ms | 29.2% | | 10GB | 222.9ms | 149.5ms | 32.9% | | 20GB | 446.2ms | 276.3ms | 38.1% | +-----------+---------+---------+-----------+ Tested on a 256GB mobile device with an SM8750 chipset. Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Reviewed-by: Sunmin Jeong <s_min.jeong@samsung.com> Signed-off-by: Yunji Kang <yunji0.kang@samsung.com> --- fs/f2fs/data.c | 3 +++ fs/f2fs/f2fs.h | 1 + fs/f2fs/node.c | 4 +++- 3 files changed, 7 insertions(+), 1 deletion(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 7961e0ddfca3..ab3117e3b24a 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -1572,6 +1572,9 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map, int flag) pgofs = (pgoff_t)map->m_lblk; end = pgofs + maxblocks; + if (flag == F2FS_GET_BLOCK_PRECACHE) + mode = LOOKUP_NODE_PRECACHE; + next_dnode: if (map->m_may_create) { if (f2fs_lfs_mode(sbi)) diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 9d3bc9633c1d..3ce41528d48e 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -651,6 +651,7 @@ enum { * look up a node with readahead called * by get_data_block. */ + LOOKUP_NODE_PRECACHE, /* look up a node for F2FS_GET_BLOCK_PRECACHE */ }; #define DEFAULT_RETRY_IO_COUNT 8 /* maximum retry read IO or flush count */ diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index 4254db453b2d..50be167e5c59 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -860,7 +860,9 @@ int f2fs_get_dnode_of_data(struct dnode_of_data *dn, pgoff_t index, int mode) set_nid(parent, offset[i - 1], nids[i], i == 1); f2fs_alloc_nid_done(sbi, nids[i]); done = true; - } else if (mode == LOOKUP_NODE_RA && i == level && level > 1) { + } else if ((mode == LOOKUP_NODE_RA || + (mode == LOOKUP_NODE_PRECACHE && offset[i - 1] % MAX_RA_NODE == 0)) + && i == level && level > 1) { nfolio[i] = f2fs_get_node_folio_ra(parent, offset[i - 1]); if (IS_ERR(nfolio[i])) { err = PTR_ERR(nfolio[i]); -- 2.34.1 _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel ^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH] f2fs: readahead node block in F2FS_GET_BLOCK_PRECACHE mode @ 2025-09-17 5:52 ` Yunji Kang 0 siblings, 0 replies; 8+ messages in thread From: Yunji Kang @ 2025-09-17 5:52 UTC (permalink / raw) To: jaegeuk, chao Cc: linux-f2fs-devel, linux-kernel, Yunji Kang, Sungjong Seo, Sunmin Jeong In f2fs_precache_extents(), For large files, It requires reading many node blocks. Instead of reading each node block with synchronous I/O, this patch applies readahead so that node blocks can be fetched in advance. It reduces the overhead of repeated sync reads and improves efficiency when precaching extents of large files. I created a file with the same largest extent and executed the test. For this experiment, I set the file's largest extent with an offset of 0 and a size of 1GB. I configured the remaining area with 100MB extents. 5GB test file: dd if=/dev/urandom of=test1 bs=1m count=5120 cp test1 test2 fsync test1 dd if=test1 of=test2 bs=1m skip=1024 seek=1024 count=100 conv=notrunc dd if=test1 of=test2 bs=1m skip=1224 seek=1224 count=100 conv=notrunc ... dd if=test1 of=test2 bs=1m skip=5024 seek=5024 count=100 conv=notrunc reboot I also created 10GB and 20GB files with large extents using the same method. ioctl(F2FS_IOC_PRECACHE_EXTENTS) test results are as follows: +-----------+---------+---------+-----------+ | File size | Before | After | Reduction | +-----------+---------+---------+-----------+ | 5GB | 101.8ms | 72.1ms | 29.2% | | 10GB | 222.9ms | 149.5ms | 32.9% | | 20GB | 446.2ms | 276.3ms | 38.1% | +-----------+---------+---------+-----------+ Tested on a 256GB mobile device with an SM8750 chipset. Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Reviewed-by: Sunmin Jeong <s_min.jeong@samsung.com> Signed-off-by: Yunji Kang <yunji0.kang@samsung.com> --- fs/f2fs/data.c | 3 +++ fs/f2fs/f2fs.h | 1 + fs/f2fs/node.c | 4 +++- 3 files changed, 7 insertions(+), 1 deletion(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 7961e0ddfca3..ab3117e3b24a 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -1572,6 +1572,9 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map, int flag) pgofs = (pgoff_t)map->m_lblk; end = pgofs + maxblocks; + if (flag == F2FS_GET_BLOCK_PRECACHE) + mode = LOOKUP_NODE_PRECACHE; + next_dnode: if (map->m_may_create) { if (f2fs_lfs_mode(sbi)) diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 9d3bc9633c1d..3ce41528d48e 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -651,6 +651,7 @@ enum { * look up a node with readahead called * by get_data_block. */ + LOOKUP_NODE_PRECACHE, /* look up a node for F2FS_GET_BLOCK_PRECACHE */ }; #define DEFAULT_RETRY_IO_COUNT 8 /* maximum retry read IO or flush count */ diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index 4254db453b2d..50be167e5c59 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -860,7 +860,9 @@ int f2fs_get_dnode_of_data(struct dnode_of_data *dn, pgoff_t index, int mode) set_nid(parent, offset[i - 1], nids[i], i == 1); f2fs_alloc_nid_done(sbi, nids[i]); done = true; - } else if (mode == LOOKUP_NODE_RA && i == level && level > 1) { + } else if ((mode == LOOKUP_NODE_RA || + (mode == LOOKUP_NODE_PRECACHE && offset[i - 1] % MAX_RA_NODE == 0)) + && i == level && level > 1) { nfolio[i] = f2fs_get_node_folio_ra(parent, offset[i - 1]); if (IS_ERR(nfolio[i])) { err = PTR_ERR(nfolio[i]); -- 2.34.1 ^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [f2fs-dev] [PATCH] f2fs: readahead node block in F2FS_GET_BLOCK_PRECACHE mode 2025-09-17 5:52 ` Yunji Kang @ 2025-09-18 2:09 ` Chao Yu -1 siblings, 0 replies; 8+ messages in thread From: Chao Yu via Linux-f2fs-devel @ 2025-09-18 2:09 UTC (permalink / raw) To: Yunji Kang, jaegeuk; +Cc: linux-kernel, Sungjong Seo, linux-f2fs-devel On 9/17/25 13:52, Yunji Kang wrote: > In f2fs_precache_extents(), For large files, It requires reading many > node blocks. Instead of reading each node block with synchronous I/O, > this patch applies readahead so that node blocks can be fetched in > advance. > > It reduces the overhead of repeated sync reads and improves efficiency > when precaching extents of large files. > > I created a file with the same largest extent and executed the test. > For this experiment, I set the file's largest extent with an offset of 0 > and a size of 1GB. I configured the remaining area with 100MB extents. > > 5GB test file: > dd if=/dev/urandom of=test1 bs=1m count=5120 > cp test1 test2 > fsync test1 > dd if=test1 of=test2 bs=1m skip=1024 seek=1024 count=100 conv=notrunc > dd if=test1 of=test2 bs=1m skip=1224 seek=1224 count=100 conv=notrunc > ... > dd if=test1 of=test2 bs=1m skip=5024 seek=5024 count=100 conv=notrunc > reboot > > I also created 10GB and 20GB files with large extents using the same > method. > > ioctl(F2FS_IOC_PRECACHE_EXTENTS) test results are as follows: > +-----------+---------+---------+-----------+ > | File size | Before | After | Reduction | > +-----------+---------+---------+-----------+ > | 5GB | 101.8ms | 72.1ms | 29.2% | > | 10GB | 222.9ms | 149.5ms | 32.9% | > | 20GB | 446.2ms | 276.3ms | 38.1% | > +-----------+---------+---------+-----------+ > Tested on a 256GB mobile device with an SM8750 chipset. > > Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> > Reviewed-by: Sunmin Jeong <s_min.jeong@samsung.com> > Signed-off-by: Yunji Kang <yunji0.kang@samsung.com> > --- > fs/f2fs/data.c | 3 +++ > fs/f2fs/f2fs.h | 1 + > fs/f2fs/node.c | 4 +++- > 3 files changed, 7 insertions(+), 1 deletion(-) > > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > index 7961e0ddfca3..ab3117e3b24a 100644 > --- a/fs/f2fs/data.c > +++ b/fs/f2fs/data.c > @@ -1572,6 +1572,9 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map, int flag) > pgofs = (pgoff_t)map->m_lblk; > end = pgofs + maxblocks; > > + if (flag == F2FS_GET_BLOCK_PRECACHE) > + mode = LOOKUP_NODE_PRECACHE; > + > next_dnode: > if (map->m_may_create) { > if (f2fs_lfs_mode(sbi)) > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > index 9d3bc9633c1d..3ce41528d48e 100644 > --- a/fs/f2fs/f2fs.h > +++ b/fs/f2fs/f2fs.h > @@ -651,6 +651,7 @@ enum { > * look up a node with readahead called > * by get_data_block. > */ > + LOOKUP_NODE_PRECACHE, /* look up a node for F2FS_GET_BLOCK_PRECACHE */ > }; > > #define DEFAULT_RETRY_IO_COUNT 8 /* maximum retry read IO or flush count */ > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c > index 4254db453b2d..50be167e5c59 100644 > --- a/fs/f2fs/node.c > +++ b/fs/f2fs/node.c > @@ -860,7 +860,9 @@ int f2fs_get_dnode_of_data(struct dnode_of_data *dn, pgoff_t index, int mode) > set_nid(parent, offset[i - 1], nids[i], i == 1); > f2fs_alloc_nid_done(sbi, nids[i]); > done = true; > - } else if (mode == LOOKUP_NODE_RA && i == level && level > 1) { > + } else if ((mode == LOOKUP_NODE_RA || Does this change the logic for mode = LOOKUP_NODE_RA? Not sure, do you mean this? if ((i == level && level > 1) && (mode == LOOKUP_NODE_RA || (mode == LOOKUP_NODE_PRECACHE && offset[i - 1] % MAX_RA_NODE == 0))) Thanks, > + (mode == LOOKUP_NODE_PRECACHE && offset[i - 1] % MAX_RA_NODE == 0)) > + && i == level && level > 1) { > nfolio[i] = f2fs_get_node_folio_ra(parent, offset[i - 1]); > if (IS_ERR(nfolio[i])) { > err = PTR_ERR(nfolio[i]); _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] f2fs: readahead node block in F2FS_GET_BLOCK_PRECACHE mode @ 2025-09-18 2:09 ` Chao Yu 0 siblings, 0 replies; 8+ messages in thread From: Chao Yu @ 2025-09-18 2:09 UTC (permalink / raw) To: Yunji Kang, jaegeuk Cc: chao, linux-f2fs-devel, linux-kernel, Sungjong Seo, Sunmin Jeong On 9/17/25 13:52, Yunji Kang wrote: > In f2fs_precache_extents(), For large files, It requires reading many > node blocks. Instead of reading each node block with synchronous I/O, > this patch applies readahead so that node blocks can be fetched in > advance. > > It reduces the overhead of repeated sync reads and improves efficiency > when precaching extents of large files. > > I created a file with the same largest extent and executed the test. > For this experiment, I set the file's largest extent with an offset of 0 > and a size of 1GB. I configured the remaining area with 100MB extents. > > 5GB test file: > dd if=/dev/urandom of=test1 bs=1m count=5120 > cp test1 test2 > fsync test1 > dd if=test1 of=test2 bs=1m skip=1024 seek=1024 count=100 conv=notrunc > dd if=test1 of=test2 bs=1m skip=1224 seek=1224 count=100 conv=notrunc > ... > dd if=test1 of=test2 bs=1m skip=5024 seek=5024 count=100 conv=notrunc > reboot > > I also created 10GB and 20GB files with large extents using the same > method. > > ioctl(F2FS_IOC_PRECACHE_EXTENTS) test results are as follows: > +-----------+---------+---------+-----------+ > | File size | Before | After | Reduction | > +-----------+---------+---------+-----------+ > | 5GB | 101.8ms | 72.1ms | 29.2% | > | 10GB | 222.9ms | 149.5ms | 32.9% | > | 20GB | 446.2ms | 276.3ms | 38.1% | > +-----------+---------+---------+-----------+ > Tested on a 256GB mobile device with an SM8750 chipset. > > Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> > Reviewed-by: Sunmin Jeong <s_min.jeong@samsung.com> > Signed-off-by: Yunji Kang <yunji0.kang@samsung.com> > --- > fs/f2fs/data.c | 3 +++ > fs/f2fs/f2fs.h | 1 + > fs/f2fs/node.c | 4 +++- > 3 files changed, 7 insertions(+), 1 deletion(-) > > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > index 7961e0ddfca3..ab3117e3b24a 100644 > --- a/fs/f2fs/data.c > +++ b/fs/f2fs/data.c > @@ -1572,6 +1572,9 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map, int flag) > pgofs = (pgoff_t)map->m_lblk; > end = pgofs + maxblocks; > > + if (flag == F2FS_GET_BLOCK_PRECACHE) > + mode = LOOKUP_NODE_PRECACHE; > + > next_dnode: > if (map->m_may_create) { > if (f2fs_lfs_mode(sbi)) > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > index 9d3bc9633c1d..3ce41528d48e 100644 > --- a/fs/f2fs/f2fs.h > +++ b/fs/f2fs/f2fs.h > @@ -651,6 +651,7 @@ enum { > * look up a node with readahead called > * by get_data_block. > */ > + LOOKUP_NODE_PRECACHE, /* look up a node for F2FS_GET_BLOCK_PRECACHE */ > }; > > #define DEFAULT_RETRY_IO_COUNT 8 /* maximum retry read IO or flush count */ > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c > index 4254db453b2d..50be167e5c59 100644 > --- a/fs/f2fs/node.c > +++ b/fs/f2fs/node.c > @@ -860,7 +860,9 @@ int f2fs_get_dnode_of_data(struct dnode_of_data *dn, pgoff_t index, int mode) > set_nid(parent, offset[i - 1], nids[i], i == 1); > f2fs_alloc_nid_done(sbi, nids[i]); > done = true; > - } else if (mode == LOOKUP_NODE_RA && i == level && level > 1) { > + } else if ((mode == LOOKUP_NODE_RA || Does this change the logic for mode = LOOKUP_NODE_RA? Not sure, do you mean this? if ((i == level && level > 1) && (mode == LOOKUP_NODE_RA || (mode == LOOKUP_NODE_PRECACHE && offset[i - 1] % MAX_RA_NODE == 0))) Thanks, > + (mode == LOOKUP_NODE_PRECACHE && offset[i - 1] % MAX_RA_NODE == 0)) > + && i == level && level > 1) { > nfolio[i] = f2fs_get_node_folio_ra(parent, offset[i - 1]); > if (IS_ERR(nfolio[i])) { > err = PTR_ERR(nfolio[i]); ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [f2fs-dev] [PATCH] f2fs: readahead node block in F2FS_GET_BLOCK_PRECACHE mode 2025-09-18 2:09 ` Chao Yu @ 2025-09-18 4:55 ` Yunji Kang -1 siblings, 0 replies; 8+ messages in thread From: Yunji Kang @ 2025-09-18 4:55 UTC (permalink / raw) To: 'Chao Yu', jaegeuk Cc: 'Sungjong Seo', linux-kernel, linux-f2fs-devel > > In f2fs_precache_extents(), For large files, It requires reading many > > node blocks. Instead of reading each node block with synchronous I/O, > > this patch applies readahead so that node blocks can be fetched in > > advance. > > > > It reduces the overhead of repeated sync reads and improves efficiency > > when precaching extents of large files. > > > > I created a file with the same largest extent and executed the test. > > For this experiment, I set the file's largest extent with an offset of > > 0 and a size of 1GB. I configured the remaining area with 100MB extents. > > > > 5GB test file: > > dd if=/dev/urandom of=test1 bs=1m count=5120 cp test1 test2 fsync > > test1 dd if=test1 of=test2 bs=1m skip=1024 seek=1024 count=100 > > conv=notrunc dd if=test1 of=test2 bs=1m skip=1224 seek=1224 count=100 > > conv=notrunc ... > > dd if=test1 of=test2 bs=1m skip=5024 seek=5024 count=100 conv=notrunc > > reboot > > > > I also created 10GB and 20GB files with large extents using the same > > method. > > > > ioctl(F2FS_IOC_PRECACHE_EXTENTS) test results are as follows: > > +-----------+---------+---------+-----------+ > > | File size | Before | After | Reduction | > > +-----------+---------+---------+-----------+ > > | 5GB | 101.8ms | 72.1ms | 29.2% | > > | 10GB | 222.9ms | 149.5ms | 32.9% | > > | 20GB | 446.2ms | 276.3ms | 38.1% | > > +-----------+---------+---------+-----------+ > > Tested on a 256GB mobile device with an SM8750 chipset. > > > > Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> > > Reviewed-by: Sunmin Jeong <s_min.jeong@samsung.com> > > Signed-off-by: Yunji Kang <yunji0.kang@samsung.com> > > --- > > fs/f2fs/data.c | 3 +++ > > fs/f2fs/f2fs.h | 1 + > > fs/f2fs/node.c | 4 +++- > > 3 files changed, 7 insertions(+), 1 deletion(-) > > > > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index > > 7961e0ddfca3..ab3117e3b24a 100644 > > --- a/fs/f2fs/data.c > > +++ b/fs/f2fs/data.c > > @@ -1572,6 +1572,9 @@ int f2fs_map_blocks(struct inode *inode, struct > f2fs_map_blocks *map, int flag) > > pgofs = (pgoff_t)map->m_lblk; > > end = pgofs + maxblocks; > > > > + if (flag == F2FS_GET_BLOCK_PRECACHE) > > + mode = LOOKUP_NODE_PRECACHE; > > + > > next_dnode: > > if (map->m_may_create) { > > if (f2fs_lfs_mode(sbi)) > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index > > 9d3bc9633c1d..3ce41528d48e 100644 > > --- a/fs/f2fs/f2fs.h > > +++ b/fs/f2fs/f2fs.h > > @@ -651,6 +651,7 @@ enum { > > * look up a node with readahead called > > * by get_data_block. > > */ > > + LOOKUP_NODE_PRECACHE, /* look up a node for > F2FS_GET_BLOCK_PRECACHE */ > > }; > > > > #define DEFAULT_RETRY_IO_COUNT 8 /* maximum retry read IO or flush > count */ > > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index > > 4254db453b2d..50be167e5c59 100644 > > --- a/fs/f2fs/node.c > > +++ b/fs/f2fs/node.c > > @@ -860,7 +860,9 @@ int f2fs_get_dnode_of_data(struct dnode_of_data *dn, > pgoff_t index, int mode) > > set_nid(parent, offset[i - 1], nids[i], i == 1); > > f2fs_alloc_nid_done(sbi, nids[i]); > > done = true; > > - } else if (mode == LOOKUP_NODE_RA && i == level && level > 1) > { > > + } else if ((mode == LOOKUP_NODE_RA || > > Does this change the logic for mode = LOOKUP_NODE_RA? > > Not sure, do you mean this? > > if ((i == level && level > 1) && > (mode == LOOKUP_NODE_RA || > (mode == LOOKUP_NODE_PRECACHE && > offset[i - 1] % MAX_RA_NODE == 0))) > > Thanks, > > > + (mode == LOOKUP_NODE_PRECACHE && offset[i - 1] % > MAX_RA_NODE == 0)) > > + && i == level && level > 1) { > > nfolio[i] = f2fs_get_node_folio_ra(parent, offset[i - > 1]); > > if (IS_ERR(nfolio[i])) { > > err = PTR_ERR(nfolio[i]); I think the code has the same meaning. The version you wrote looks more readable, so would it be okay if I change the patch with your code? Also, I did not change the logic for mode = LOOKUP_NODE_RA; I only added a condition for when readahead is performed. Thanks. _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel ^ permalink raw reply [flat|nested] 8+ messages in thread
* RE: [PATCH] f2fs: readahead node block in F2FS_GET_BLOCK_PRECACHE mode @ 2025-09-18 4:55 ` Yunji Kang 0 siblings, 0 replies; 8+ messages in thread From: Yunji Kang @ 2025-09-18 4:55 UTC (permalink / raw) To: 'Chao Yu', jaegeuk Cc: linux-f2fs-devel, linux-kernel, 'Sungjong Seo', 'Sunmin Jeong' > > In f2fs_precache_extents(), For large files, It requires reading many > > node blocks. Instead of reading each node block with synchronous I/O, > > this patch applies readahead so that node blocks can be fetched in > > advance. > > > > It reduces the overhead of repeated sync reads and improves efficiency > > when precaching extents of large files. > > > > I created a file with the same largest extent and executed the test. > > For this experiment, I set the file's largest extent with an offset of > > 0 and a size of 1GB. I configured the remaining area with 100MB extents. > > > > 5GB test file: > > dd if=/dev/urandom of=test1 bs=1m count=5120 cp test1 test2 fsync > > test1 dd if=test1 of=test2 bs=1m skip=1024 seek=1024 count=100 > > conv=notrunc dd if=test1 of=test2 bs=1m skip=1224 seek=1224 count=100 > > conv=notrunc ... > > dd if=test1 of=test2 bs=1m skip=5024 seek=5024 count=100 conv=notrunc > > reboot > > > > I also created 10GB and 20GB files with large extents using the same > > method. > > > > ioctl(F2FS_IOC_PRECACHE_EXTENTS) test results are as follows: > > +-----------+---------+---------+-----------+ > > | File size | Before | After | Reduction | > > +-----------+---------+---------+-----------+ > > | 5GB | 101.8ms | 72.1ms | 29.2% | > > | 10GB | 222.9ms | 149.5ms | 32.9% | > > | 20GB | 446.2ms | 276.3ms | 38.1% | > > +-----------+---------+---------+-----------+ > > Tested on a 256GB mobile device with an SM8750 chipset. > > > > Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> > > Reviewed-by: Sunmin Jeong <s_min.jeong@samsung.com> > > Signed-off-by: Yunji Kang <yunji0.kang@samsung.com> > > --- > > fs/f2fs/data.c | 3 +++ > > fs/f2fs/f2fs.h | 1 + > > fs/f2fs/node.c | 4 +++- > > 3 files changed, 7 insertions(+), 1 deletion(-) > > > > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index > > 7961e0ddfca3..ab3117e3b24a 100644 > > --- a/fs/f2fs/data.c > > +++ b/fs/f2fs/data.c > > @@ -1572,6 +1572,9 @@ int f2fs_map_blocks(struct inode *inode, struct > f2fs_map_blocks *map, int flag) > > pgofs = (pgoff_t)map->m_lblk; > > end = pgofs + maxblocks; > > > > + if (flag == F2FS_GET_BLOCK_PRECACHE) > > + mode = LOOKUP_NODE_PRECACHE; > > + > > next_dnode: > > if (map->m_may_create) { > > if (f2fs_lfs_mode(sbi)) > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index > > 9d3bc9633c1d..3ce41528d48e 100644 > > --- a/fs/f2fs/f2fs.h > > +++ b/fs/f2fs/f2fs.h > > @@ -651,6 +651,7 @@ enum { > > * look up a node with readahead called > > * by get_data_block. > > */ > > + LOOKUP_NODE_PRECACHE, /* look up a node for > F2FS_GET_BLOCK_PRECACHE */ > > }; > > > > #define DEFAULT_RETRY_IO_COUNT 8 /* maximum retry read IO or flush > count */ > > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index > > 4254db453b2d..50be167e5c59 100644 > > --- a/fs/f2fs/node.c > > +++ b/fs/f2fs/node.c > > @@ -860,7 +860,9 @@ int f2fs_get_dnode_of_data(struct dnode_of_data *dn, > pgoff_t index, int mode) > > set_nid(parent, offset[i - 1], nids[i], i == 1); > > f2fs_alloc_nid_done(sbi, nids[i]); > > done = true; > > - } else if (mode == LOOKUP_NODE_RA && i == level && level > 1) > { > > + } else if ((mode == LOOKUP_NODE_RA || > > Does this change the logic for mode = LOOKUP_NODE_RA? > > Not sure, do you mean this? > > if ((i == level && level > 1) && > (mode == LOOKUP_NODE_RA || > (mode == LOOKUP_NODE_PRECACHE && > offset[i - 1] % MAX_RA_NODE == 0))) > > Thanks, > > > + (mode == LOOKUP_NODE_PRECACHE && offset[i - 1] % > MAX_RA_NODE == 0)) > > + && i == level && level > 1) { > > nfolio[i] = f2fs_get_node_folio_ra(parent, offset[i - > 1]); > > if (IS_ERR(nfolio[i])) { > > err = PTR_ERR(nfolio[i]); I think the code has the same meaning. The version you wrote looks more readable, so would it be okay if I change the patch with your code? Also, I did not change the logic for mode = LOOKUP_NODE_RA; I only added a condition for when readahead is performed. Thanks. ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [f2fs-dev] [PATCH] f2fs: readahead node block in F2FS_GET_BLOCK_PRECACHE mode 2025-09-18 4:55 ` Yunji Kang @ 2025-09-18 7:02 ` Chao Yu -1 siblings, 0 replies; 8+ messages in thread From: Chao Yu via Linux-f2fs-devel @ 2025-09-18 7:02 UTC (permalink / raw) To: Yunji Kang, jaegeuk Cc: linux-kernel, 'Sungjong Seo', linux-f2fs-devel On 9/18/25 12:55, Yunji Kang wrote: >>> In f2fs_precache_extents(), For large files, It requires reading many >>> node blocks. Instead of reading each node block with synchronous I/O, >>> this patch applies readahead so that node blocks can be fetched in >>> advance. >>> >>> It reduces the overhead of repeated sync reads and improves efficiency >>> when precaching extents of large files. >>> >>> I created a file with the same largest extent and executed the test. >>> For this experiment, I set the file's largest extent with an offset of >>> 0 and a size of 1GB. I configured the remaining area with 100MB extents. >>> >>> 5GB test file: >>> dd if=/dev/urandom of=test1 bs=1m count=5120 cp test1 test2 fsync >>> test1 dd if=test1 of=test2 bs=1m skip=1024 seek=1024 count=100 >>> conv=notrunc dd if=test1 of=test2 bs=1m skip=1224 seek=1224 count=100 >>> conv=notrunc ... >>> dd if=test1 of=test2 bs=1m skip=5024 seek=5024 count=100 conv=notrunc >>> reboot >>> >>> I also created 10GB and 20GB files with large extents using the same >>> method. >>> >>> ioctl(F2FS_IOC_PRECACHE_EXTENTS) test results are as follows: >>> +-----------+---------+---------+-----------+ >>> | File size | Before | After | Reduction | >>> +-----------+---------+---------+-----------+ >>> | 5GB | 101.8ms | 72.1ms | 29.2% | >>> | 10GB | 222.9ms | 149.5ms | 32.9% | >>> | 20GB | 446.2ms | 276.3ms | 38.1% | >>> +-----------+---------+---------+-----------+ >>> Tested on a 256GB mobile device with an SM8750 chipset. >>> >>> Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> >>> Reviewed-by: Sunmin Jeong <s_min.jeong@samsung.com> >>> Signed-off-by: Yunji Kang <yunji0.kang@samsung.com> >>> --- >>> fs/f2fs/data.c | 3 +++ >>> fs/f2fs/f2fs.h | 1 + >>> fs/f2fs/node.c | 4 +++- >>> 3 files changed, 7 insertions(+), 1 deletion(-) >>> >>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index >>> 7961e0ddfca3..ab3117e3b24a 100644 >>> --- a/fs/f2fs/data.c >>> +++ b/fs/f2fs/data.c >>> @@ -1572,6 +1572,9 @@ int f2fs_map_blocks(struct inode *inode, struct >> f2fs_map_blocks *map, int flag) >>> pgofs = (pgoff_t)map->m_lblk; >>> end = pgofs + maxblocks; >>> >>> + if (flag == F2FS_GET_BLOCK_PRECACHE) >>> + mode = LOOKUP_NODE_PRECACHE; >>> + >>> next_dnode: >>> if (map->m_may_create) { >>> if (f2fs_lfs_mode(sbi)) >>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index >>> 9d3bc9633c1d..3ce41528d48e 100644 >>> --- a/fs/f2fs/f2fs.h >>> +++ b/fs/f2fs/f2fs.h >>> @@ -651,6 +651,7 @@ enum { >>> * look up a node with readahead called >>> * by get_data_block. >>> */ >>> + LOOKUP_NODE_PRECACHE, /* look up a node for >> F2FS_GET_BLOCK_PRECACHE */ >>> }; >>> >>> #define DEFAULT_RETRY_IO_COUNT 8 /* maximum retry read IO or flush >> count */ >>> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index >>> 4254db453b2d..50be167e5c59 100644 >>> --- a/fs/f2fs/node.c >>> +++ b/fs/f2fs/node.c >>> @@ -860,7 +860,9 @@ int f2fs_get_dnode_of_data(struct dnode_of_data *dn, >> pgoff_t index, int mode) >>> set_nid(parent, offset[i - 1], nids[i], i == 1); >>> f2fs_alloc_nid_done(sbi, nids[i]); >>> done = true; >>> - } else if (mode == LOOKUP_NODE_RA && i == level && level > 1) >> { >>> + } else if ((mode == LOOKUP_NODE_RA || >> >> Does this change the logic for mode = LOOKUP_NODE_RA? >> >> Not sure, do you mean this? >> >> if ((i == level && level > 1) && >> (mode == LOOKUP_NODE_RA || >> (mode == LOOKUP_NODE_PRECACHE && >> offset[i - 1] % MAX_RA_NODE == 0))) >> >> Thanks, >> >>> + (mode == LOOKUP_NODE_PRECACHE && offset[i - 1] % >> MAX_RA_NODE == 0)) >>> + && i == level && level > 1) { >>> nfolio[i] = f2fs_get_node_folio_ra(parent, offset[i - >> 1]); >>> if (IS_ERR(nfolio[i])) { >>> err = PTR_ERR(nfolio[i]); > > I think the code has the same meaning. > The version you wrote looks more readable, so would it be okay if I change the patch with your code? Sure, please go ahead. > > Also, I did not change the logic for mode = LOOKUP_NODE_RA; I only added a condition for when readahead is performed. Oh, I see, I missed the parenthesis, sorry. Thanks, > > Thanks. > _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] f2fs: readahead node block in F2FS_GET_BLOCK_PRECACHE mode @ 2025-09-18 7:02 ` Chao Yu 0 siblings, 0 replies; 8+ messages in thread From: Chao Yu @ 2025-09-18 7:02 UTC (permalink / raw) To: Yunji Kang, jaegeuk Cc: chao, linux-f2fs-devel, linux-kernel, 'Sungjong Seo', 'Sunmin Jeong' On 9/18/25 12:55, Yunji Kang wrote: >>> In f2fs_precache_extents(), For large files, It requires reading many >>> node blocks. Instead of reading each node block with synchronous I/O, >>> this patch applies readahead so that node blocks can be fetched in >>> advance. >>> >>> It reduces the overhead of repeated sync reads and improves efficiency >>> when precaching extents of large files. >>> >>> I created a file with the same largest extent and executed the test. >>> For this experiment, I set the file's largest extent with an offset of >>> 0 and a size of 1GB. I configured the remaining area with 100MB extents. >>> >>> 5GB test file: >>> dd if=/dev/urandom of=test1 bs=1m count=5120 cp test1 test2 fsync >>> test1 dd if=test1 of=test2 bs=1m skip=1024 seek=1024 count=100 >>> conv=notrunc dd if=test1 of=test2 bs=1m skip=1224 seek=1224 count=100 >>> conv=notrunc ... >>> dd if=test1 of=test2 bs=1m skip=5024 seek=5024 count=100 conv=notrunc >>> reboot >>> >>> I also created 10GB and 20GB files with large extents using the same >>> method. >>> >>> ioctl(F2FS_IOC_PRECACHE_EXTENTS) test results are as follows: >>> +-----------+---------+---------+-----------+ >>> | File size | Before | After | Reduction | >>> +-----------+---------+---------+-----------+ >>> | 5GB | 101.8ms | 72.1ms | 29.2% | >>> | 10GB | 222.9ms | 149.5ms | 32.9% | >>> | 20GB | 446.2ms | 276.3ms | 38.1% | >>> +-----------+---------+---------+-----------+ >>> Tested on a 256GB mobile device with an SM8750 chipset. >>> >>> Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> >>> Reviewed-by: Sunmin Jeong <s_min.jeong@samsung.com> >>> Signed-off-by: Yunji Kang <yunji0.kang@samsung.com> >>> --- >>> fs/f2fs/data.c | 3 +++ >>> fs/f2fs/f2fs.h | 1 + >>> fs/f2fs/node.c | 4 +++- >>> 3 files changed, 7 insertions(+), 1 deletion(-) >>> >>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index >>> 7961e0ddfca3..ab3117e3b24a 100644 >>> --- a/fs/f2fs/data.c >>> +++ b/fs/f2fs/data.c >>> @@ -1572,6 +1572,9 @@ int f2fs_map_blocks(struct inode *inode, struct >> f2fs_map_blocks *map, int flag) >>> pgofs = (pgoff_t)map->m_lblk; >>> end = pgofs + maxblocks; >>> >>> + if (flag == F2FS_GET_BLOCK_PRECACHE) >>> + mode = LOOKUP_NODE_PRECACHE; >>> + >>> next_dnode: >>> if (map->m_may_create) { >>> if (f2fs_lfs_mode(sbi)) >>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index >>> 9d3bc9633c1d..3ce41528d48e 100644 >>> --- a/fs/f2fs/f2fs.h >>> +++ b/fs/f2fs/f2fs.h >>> @@ -651,6 +651,7 @@ enum { >>> * look up a node with readahead called >>> * by get_data_block. >>> */ >>> + LOOKUP_NODE_PRECACHE, /* look up a node for >> F2FS_GET_BLOCK_PRECACHE */ >>> }; >>> >>> #define DEFAULT_RETRY_IO_COUNT 8 /* maximum retry read IO or flush >> count */ >>> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index >>> 4254db453b2d..50be167e5c59 100644 >>> --- a/fs/f2fs/node.c >>> +++ b/fs/f2fs/node.c >>> @@ -860,7 +860,9 @@ int f2fs_get_dnode_of_data(struct dnode_of_data *dn, >> pgoff_t index, int mode) >>> set_nid(parent, offset[i - 1], nids[i], i == 1); >>> f2fs_alloc_nid_done(sbi, nids[i]); >>> done = true; >>> - } else if (mode == LOOKUP_NODE_RA && i == level && level > 1) >> { >>> + } else if ((mode == LOOKUP_NODE_RA || >> >> Does this change the logic for mode = LOOKUP_NODE_RA? >> >> Not sure, do you mean this? >> >> if ((i == level && level > 1) && >> (mode == LOOKUP_NODE_RA || >> (mode == LOOKUP_NODE_PRECACHE && >> offset[i - 1] % MAX_RA_NODE == 0))) >> >> Thanks, >> >>> + (mode == LOOKUP_NODE_PRECACHE && offset[i - 1] % >> MAX_RA_NODE == 0)) >>> + && i == level && level > 1) { >>> nfolio[i] = f2fs_get_node_folio_ra(parent, offset[i - >> 1]); >>> if (IS_ERR(nfolio[i])) { >>> err = PTR_ERR(nfolio[i]); > > I think the code has the same meaning. > The version you wrote looks more readable, so would it be okay if I change the patch with your code? Sure, please go ahead. > > Also, I did not change the logic for mode = LOOKUP_NODE_RA; I only added a condition for when readahead is performed. Oh, I see, I missed the parenthesis, sorry. Thanks, > > Thanks. > ^ permalink raw reply [flat|nested] 8+ messages in thread
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2025-09-17 5:52 ` [f2fs-dev] [PATCH] f2fs: readahead node block in F2FS_GET_BLOCK_PRECACHE mode Yunji Kang
2025-09-17 5:52 ` Yunji Kang
2025-09-18 2:09 ` [f2fs-dev] " Chao Yu via Linux-f2fs-devel
2025-09-18 2:09 ` Chao Yu
2025-09-18 4:55 ` [f2fs-dev] " Yunji Kang
2025-09-18 4:55 ` Yunji Kang
2025-09-18 7:02 ` [f2fs-dev] " Chao Yu via Linux-f2fs-devel
2025-09-18 7:02 ` Chao Yu
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