| Message ID | 20230801172201.1923299-6-hch@lst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/6] fs: remove emergency_thaw_bdev | expand |
On Tue, Aug 01, 2023 at 07:22:00PM +0200, Christoph Hellwig wrote: > Use iomap in buffer_head compat mode to write to block devices. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> > Reviewed-by: Pankaj Raghav <p.raghav@samsung.com> > Reviewed-by: Hannes Reinecke <hare@suse.de> > --- Reviewed-by: Christian Brauner <brauner@kernel.org>
Looks good,
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Hi Christoph, On Tue, Aug 01, 2023 at 07:22:00PM +0200, Christoph Hellwig wrote: > Use iomap in buffer_head compat mode to write to block devices. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> > Reviewed-by: Pankaj Raghav <p.raghav@samsung.com> > Reviewed-by: Hannes Reinecke <hare@suse.de> > --- > block/Kconfig | 1 + > block/fops.c | 31 +++++++++++++++++++++++++++++-- > 2 files changed, 30 insertions(+), 2 deletions(-) > > diff --git a/block/Kconfig b/block/Kconfig > index 86122e459fe046..1a13ef0b1ca10c 100644 > --- a/block/Kconfig > +++ b/block/Kconfig > @@ -5,6 +5,7 @@ > menuconfig BLOCK > bool "Enable the block layer" if EXPERT > default y > + select FS_IOMAP > select SBITMAP > help > Provide block layer support for the kernel. > diff --git a/block/fops.c b/block/fops.c > index f0b822c28ddfe2..063ece37d44e44 100644 > --- a/block/fops.c > +++ b/block/fops.c > @@ -15,6 +15,7 @@ > #include <linux/falloc.h> > #include <linux/suspend.h> > #include <linux/fs.h> > +#include <linux/iomap.h> > #include <linux/module.h> > #include "blk.h" > > @@ -386,6 +387,27 @@ static ssize_t blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter) > return __blkdev_direct_IO(iocb, iter, bio_max_segs(nr_pages)); > } > > +static int blkdev_iomap_begin(struct inode *inode, loff_t offset, loff_t length, > + unsigned int flags, struct iomap *iomap, struct iomap *srcmap) > +{ > + struct block_device *bdev = I_BDEV(inode); > + loff_t isize = i_size_read(inode); > + > + iomap->bdev = bdev; > + iomap->offset = ALIGN_DOWN(offset, bdev_logical_block_size(bdev)); > + if (iomap->offset >= isize) > + return -EIO; > + iomap->type = IOMAP_MAPPED; > + iomap->addr = iomap->offset; > + iomap->length = isize - iomap->offset; > + iomap->flags |= IOMAP_F_BUFFER_HEAD; > + return 0; > +} > + > +static const struct iomap_ops blkdev_iomap_ops = { > + .iomap_begin = blkdev_iomap_begin, > +}; > + > static int blkdev_writepage(struct page *page, struct writeback_control *wbc) > { > return block_write_full_page(page, blkdev_get_block, wbc); > @@ -556,6 +578,11 @@ blkdev_direct_write(struct kiocb *iocb, struct iov_iter *from) > return written; > } > > +static ssize_t blkdev_buffered_write(struct kiocb *iocb, struct iov_iter *from) > +{ > + return iomap_file_buffered_write(iocb, from, &blkdev_iomap_ops); > +} > + > /* > * Write data to the block device. Only intended for the block device itself > * and the raw driver which basically is a fake block device. > @@ -605,9 +632,9 @@ static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) > ret = blkdev_direct_write(iocb, from); > if (ret >= 0 && iov_iter_count(from)) > ret = direct_write_fallback(iocb, from, ret, > - generic_perform_write(iocb, from)); > + blkdev_buffered_write(iocb, from)); > } else { > - ret = generic_perform_write(iocb, from); > + ret = blkdev_buffered_write(iocb, from); > } > > if (ret > 0) I'm testing SSD block device write performance recently. I found the write speed descrased greatly on my board (330MB/s -> 130MB/s). Then I spent some time to find cause, finally find that it's caused by this patch and if I revert this patch, write speed can recover to 330MB/s. I'm using below command to test write performance: dd if=/dev/zero of=/dev/sda bs=4M count=1024 And I also do more tests to get more findings. In short, I found write speed changes with the "bs=" parameter. I totally write 4GB data to sda for each test, the results as below: - dd if=/dev/zero of=/dev/sda bs=400K count=10485 (334 MB/s) - dd if=/dev/zero of=/dev/sda bs=800K count=5242 (278 MB/s) - dd if=/dev/zero of=/dev/sda bs=1600K count=2621 (204 MB/s) - dd if=/dev/zero of=/dev/sda bs=2200K count=1906 (170 MB/s) - dd if=/dev/zero of=/dev/sda bs=3000K count=1398 (150 MB/s) - dd if=/dev/zero of=/dev/sda bs=4500K count=932 (139 MB/s) When this patch reverted, I got below results: - dd if=/dev/zero of=/dev/sda bs=400K count=10485 (339 MB/s) - dd if=/dev/zero of=/dev/sda bs=800K count=5242 (330 MB/s) - dd if=/dev/zero of=/dev/sda bs=1600K count=2621 (332 MB/s) - dd if=/dev/zero of=/dev/sda bs=2200K count=1906 (333 MB/s) - dd if=/dev/zero of=/dev/sda bs=3000K count=1398 (333 MB/s) - dd if=/dev/zero of=/dev/sda bs=4500K count=932 (333 MB/s) I just want to know if this results is expected when uses iomap, or it's a real issue? Many thanks in advance! Best Regards, Xu Yang > -- > 2.39.2 >
On Fri, Apr 26, 2024 at 06:37:27PM +0800, Xu Yang wrote: > Hi Christoph, > > On Tue, Aug 01, 2023 at 07:22:00PM +0200, Christoph Hellwig wrote: > > Use iomap in buffer_head compat mode to write to block devices. > > > > Signed-off-by: Christoph Hellwig <hch@lst.de> > > Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> > > Reviewed-by: Pankaj Raghav <p.raghav@samsung.com> > > Reviewed-by: Hannes Reinecke <hare@suse.de> > > --- > > block/Kconfig | 1 + > > block/fops.c | 31 +++++++++++++++++++++++++++++-- > > 2 files changed, 30 insertions(+), 2 deletions(-) > > > > diff --git a/block/Kconfig b/block/Kconfig > > index 86122e459fe046..1a13ef0b1ca10c 100644 > > --- a/block/Kconfig > > +++ b/block/Kconfig > > @@ -5,6 +5,7 @@ > > menuconfig BLOCK > > bool "Enable the block layer" if EXPERT > > default y > > + select FS_IOMAP > > select SBITMAP > > help > > Provide block layer support for the kernel. > > diff --git a/block/fops.c b/block/fops.c > > index f0b822c28ddfe2..063ece37d44e44 100644 > > --- a/block/fops.c > > +++ b/block/fops.c > > @@ -15,6 +15,7 @@ > > #include <linux/falloc.h> > > #include <linux/suspend.h> > > #include <linux/fs.h> > > +#include <linux/iomap.h> > > #include <linux/module.h> > > #include "blk.h" > > > > @@ -386,6 +387,27 @@ static ssize_t blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter) > > return __blkdev_direct_IO(iocb, iter, bio_max_segs(nr_pages)); > > } > > > > +static int blkdev_iomap_begin(struct inode *inode, loff_t offset, loff_t length, > > + unsigned int flags, struct iomap *iomap, struct iomap *srcmap) > > +{ > > + struct block_device *bdev = I_BDEV(inode); > > + loff_t isize = i_size_read(inode); > > + > > + iomap->bdev = bdev; > > + iomap->offset = ALIGN_DOWN(offset, bdev_logical_block_size(bdev)); > > + if (iomap->offset >= isize) > > + return -EIO; > > + iomap->type = IOMAP_MAPPED; > > + iomap->addr = iomap->offset; > > + iomap->length = isize - iomap->offset; > > + iomap->flags |= IOMAP_F_BUFFER_HEAD; > > + return 0; > > +} > > + > > +static const struct iomap_ops blkdev_iomap_ops = { > > + .iomap_begin = blkdev_iomap_begin, > > +}; > > + > > static int blkdev_writepage(struct page *page, struct writeback_control *wbc) > > { > > return block_write_full_page(page, blkdev_get_block, wbc); > > @@ -556,6 +578,11 @@ blkdev_direct_write(struct kiocb *iocb, struct iov_iter *from) > > return written; > > } > > > > +static ssize_t blkdev_buffered_write(struct kiocb *iocb, struct iov_iter *from) > > +{ > > + return iomap_file_buffered_write(iocb, from, &blkdev_iomap_ops); > > +} > > + > > /* > > * Write data to the block device. Only intended for the block device itself > > * and the raw driver which basically is a fake block device. > > @@ -605,9 +632,9 @@ static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) > > ret = blkdev_direct_write(iocb, from); > > if (ret >= 0 && iov_iter_count(from)) > > ret = direct_write_fallback(iocb, from, ret, > > - generic_perform_write(iocb, from)); > > + blkdev_buffered_write(iocb, from)); > > } else { > > - ret = generic_perform_write(iocb, from); > > + ret = blkdev_buffered_write(iocb, from); > > } > > > > if (ret > 0) > > I'm testing SSD block device write performance recently. I found the write > speed descrased greatly on my board (330MB/s -> 130MB/s). Then I spent some > time to find cause, finally find that it's caused by this patch and if I > revert this patch, write speed can recover to 330MB/s. > > I'm using below command to test write performance: > dd if=/dev/zero of=/dev/sda bs=4M count=1024 > > And I also do more tests to get more findings. In short, I found write > speed changes with the "bs=" parameter. > > I totally write 4GB data to sda for each test, the results as below: > > - dd if=/dev/zero of=/dev/sda bs=400K count=10485 (334 MB/s) > - dd if=/dev/zero of=/dev/sda bs=800K count=5242 (278 MB/s) > - dd if=/dev/zero of=/dev/sda bs=1600K count=2621 (204 MB/s) > - dd if=/dev/zero of=/dev/sda bs=2200K count=1906 (170 MB/s) > - dd if=/dev/zero of=/dev/sda bs=3000K count=1398 (150 MB/s) > - dd if=/dev/zero of=/dev/sda bs=4500K count=932 (139 MB/s) > > When this patch reverted, I got below results: > > - dd if=/dev/zero of=/dev/sda bs=400K count=10485 (339 MB/s) > - dd if=/dev/zero of=/dev/sda bs=800K count=5242 (330 MB/s) > - dd if=/dev/zero of=/dev/sda bs=1600K count=2621 (332 MB/s) > - dd if=/dev/zero of=/dev/sda bs=2200K count=1906 (333 MB/s) > - dd if=/dev/zero of=/dev/sda bs=3000K count=1398 (333 MB/s) > - dd if=/dev/zero of=/dev/sda bs=4500K count=932 (333 MB/s) > > I just want to know if this results is expected when uses iomap, or it's > a real issue? > > Many thanks in advance! A gentle ping. > > Best Regards, > Xu Yang > > > -- > > 2.39.2 > >
diff --git a/block/Kconfig b/block/Kconfig index 86122e459fe046..1a13ef0b1ca10c 100644 --- a/block/Kconfig +++ b/block/Kconfig @@ -5,6 +5,7 @@ menuconfig BLOCK bool "Enable the block layer" if EXPERT default y + select FS_IOMAP select SBITMAP help Provide block layer support for the kernel. diff --git a/block/fops.c b/block/fops.c index f0b822c28ddfe2..063ece37d44e44 100644 --- a/block/fops.c +++ b/block/fops.c @@ -15,6 +15,7 @@ #include <linux/falloc.h> #include <linux/suspend.h> #include <linux/fs.h> +#include <linux/iomap.h> #include <linux/module.h> #include "blk.h" @@ -386,6 +387,27 @@ static ssize_t blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter) return __blkdev_direct_IO(iocb, iter, bio_max_segs(nr_pages)); } +static int blkdev_iomap_begin(struct inode *inode, loff_t offset, loff_t length, + unsigned int flags, struct iomap *iomap, struct iomap *srcmap) +{ + struct block_device *bdev = I_BDEV(inode); + loff_t isize = i_size_read(inode); + + iomap->bdev = bdev; + iomap->offset = ALIGN_DOWN(offset, bdev_logical_block_size(bdev)); + if (iomap->offset >= isize) + return -EIO; + iomap->type = IOMAP_MAPPED; + iomap->addr = iomap->offset; + iomap->length = isize - iomap->offset; + iomap->flags |= IOMAP_F_BUFFER_HEAD; + return 0; +} + +static const struct iomap_ops blkdev_iomap_ops = { + .iomap_begin = blkdev_iomap_begin, +}; + static int blkdev_writepage(struct page *page, struct writeback_control *wbc) { return block_write_full_page(page, blkdev_get_block, wbc); @@ -556,6 +578,11 @@ blkdev_direct_write(struct kiocb *iocb, struct iov_iter *from) return written; } +static ssize_t blkdev_buffered_write(struct kiocb *iocb, struct iov_iter *from) +{ + return iomap_file_buffered_write(iocb, from, &blkdev_iomap_ops); +} + /* * Write data to the block device. Only intended for the block device itself * and the raw driver which basically is a fake block device. @@ -605,9 +632,9 @@ static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) ret = blkdev_direct_write(iocb, from); if (ret >= 0 && iov_iter_count(from)) ret = direct_write_fallback(iocb, from, ret, - generic_perform_write(iocb, from)); + blkdev_buffered_write(iocb, from)); } else { - ret = generic_perform_write(iocb, from); + ret = blkdev_buffered_write(iocb, from); } if (ret > 0)