Re: [PATCH v3 00/22] loop: Issue O_DIRECT aio using bio_vec
On Mon, Oct 22, 2012 at 10:15:00AM -0500, Dave Kleikamp wrote: > This is the current version of the patchset I presented at the LSF-MM > Summit in San Francisco in April. I apologize for letting it go so > long before re-submitting. > > This patchset was begun by Zach Brown and was originally submitted for > review in October, 2009. Feedback was positive, and I have picked up > where he left off, porting his patches to the latest mainline kernel > and adding support more file systems. > > This patch series adds a kernel interface to fs/aio.c so that kernel code can > issue concurrent asynchronous IO to file systems. It adds an aio command and > file system methods which specify io memory with pages instead of userspace > addresses. > > This series was written to reduce the current overhead loop imposes by > performing synchronus buffered file system IO from a kernel thread. These > patches turn loop into a light weight layer that translates bios into iocbs. > > The downside of this is that in its current implementation, performance takes > a big hit for non-synchonous I/O, since the underlying page cache is bypassed. > The tradeoff is that all writes to the loop device make it to the underlying > media, making loop-mounted file systems recoverable. It also seems to still not fully kill thr old aio_read/write codepath. At least XFS isn't touched yet. It also doesn't seem to kill the nasty hack for in-kernel direct I/O introduced with the swap over nfs code (grep for REQ_KERNEL / KERNEL_READ / KERNEL_WRITE) -- 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 00/22] loop: Issue O_DIRECT aio using bio_vec
On Mon, Oct 22, 2012 at 10:15:00AM -0500, Dave Kleikamp wrote: This is the current version of the patchset I presented at the LSF-MM Summit in San Francisco in April. I apologize for letting it go so long before re-submitting. This patchset was begun by Zach Brown and was originally submitted for review in October, 2009. Feedback was positive, and I have picked up where he left off, porting his patches to the latest mainline kernel and adding support more file systems. This patch series adds a kernel interface to fs/aio.c so that kernel code can issue concurrent asynchronous IO to file systems. It adds an aio command and file system methods which specify io memory with pages instead of userspace addresses. This series was written to reduce the current overhead loop imposes by performing synchronus buffered file system IO from a kernel thread. These patches turn loop into a light weight layer that translates bios into iocbs. The downside of this is that in its current implementation, performance takes a big hit for non-synchonous I/O, since the underlying page cache is bypassed. The tradeoff is that all writes to the loop device make it to the underlying media, making loop-mounted file systems recoverable. It also seems to still not fully kill thr old aio_read/write codepath. At least XFS isn't touched yet. It also doesn't seem to kill the nasty hack for in-kernel direct I/O introduced with the swap over nfs code (grep for REQ_KERNEL / KERNEL_READ / KERNEL_WRITE) -- 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 00/22] loop: Issue O_DIRECT aio using bio_vec
On Mon, Oct 22, 2012 at 07:53:40PM -0500, Dave Kleikamp wrote: > On 10/22/2012 07:07 PM, Dave Chinner wrote: > > On Mon, Oct 22, 2012 at 10:15:00AM -0500, Dave Kleikamp wrote: > >> This is the current version of the patchset I presented at the LSF-MM > >> Summit in San Francisco in April. I apologize for letting it go so > >> long before re-submitting. > >> > >> This patchset was begun by Zach Brown and was originally submitted for > >> review in October, 2009. Feedback was positive, and I have picked up > >> where he left off, porting his patches to the latest mainline kernel > >> and adding support more file systems. > >> > >> This patch series adds a kernel interface to fs/aio.c so that kernel code > >> can > >> issue concurrent asynchronous IO to file systems. It adds an aio command > >> and > >> file system methods which specify io memory with pages instead of userspace > >> addresses. > >> > >> This series was written to reduce the current overhead loop imposes by > >> performing synchronus buffered file system IO from a kernel thread. These > >> patches turn loop into a light weight layer that translates bios into > >> iocbs. > > > > I note that there is no support for XFS in this patch set. Is there > > a particular problem that prevents XFS from being converted, or it > > just hasn't been done? > > It just hasn't been done. It wasn't one of the trivial ones so I put it > off at first, and after that, it's an oversight. I'll follow up with an > xfs patch for your review. Thanks Shaggy, that's all I wanted to know. No extra work for me (apart from review and testing) is fine by me. ;) Cheers, Dave. -- Dave Chinner da...@fromorbit.com -- 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 00/22] loop: Issue O_DIRECT aio using bio_vec
On 10/22/2012 07:07 PM, Dave Chinner wrote: > On Mon, Oct 22, 2012 at 10:15:00AM -0500, Dave Kleikamp wrote: >> This is the current version of the patchset I presented at the LSF-MM >> Summit in San Francisco in April. I apologize for letting it go so >> long before re-submitting. >> >> This patchset was begun by Zach Brown and was originally submitted for >> review in October, 2009. Feedback was positive, and I have picked up >> where he left off, porting his patches to the latest mainline kernel >> and adding support more file systems. >> >> This patch series adds a kernel interface to fs/aio.c so that kernel code can >> issue concurrent asynchronous IO to file systems. It adds an aio command and >> file system methods which specify io memory with pages instead of userspace >> addresses. >> >> This series was written to reduce the current overhead loop imposes by >> performing synchronus buffered file system IO from a kernel thread. These >> patches turn loop into a light weight layer that translates bios into iocbs. > > I note that there is no support for XFS in this patch set. Is there > a particular problem that prevents XFS from being converted, or it > just hasn't been done? It just hasn't been done. It wasn't one of the trivial ones so I put it off at first, and after that, it's an oversight. I'll follow up with an xfs patch for your review. Thanks, Shaggy > > Cheers, > > Dave. > -- 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 00/22] loop: Issue O_DIRECT aio using bio_vec
On Mon, Oct 22, 2012 at 10:15:00AM -0500, Dave Kleikamp wrote: > This is the current version of the patchset I presented at the LSF-MM > Summit in San Francisco in April. I apologize for letting it go so > long before re-submitting. > > This patchset was begun by Zach Brown and was originally submitted for > review in October, 2009. Feedback was positive, and I have picked up > where he left off, porting his patches to the latest mainline kernel > and adding support more file systems. > > This patch series adds a kernel interface to fs/aio.c so that kernel code can > issue concurrent asynchronous IO to file systems. It adds an aio command and > file system methods which specify io memory with pages instead of userspace > addresses. > > This series was written to reduce the current overhead loop imposes by > performing synchronus buffered file system IO from a kernel thread. These > patches turn loop into a light weight layer that translates bios into iocbs. I note that there is no support for XFS in this patch set. Is there a particular problem that prevents XFS from being converted, or it just hasn't been done? Cheers, Dave. -- Dave Chinner da...@fromorbit.com -- 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 00/22] loop: Issue O_DIRECT aio using bio_vec
On Mon, Oct 22, 2012 at 10:15:00AM -0500, Dave Kleikamp wrote: This is the current version of the patchset I presented at the LSF-MM Summit in San Francisco in April. I apologize for letting it go so long before re-submitting. This patchset was begun by Zach Brown and was originally submitted for review in October, 2009. Feedback was positive, and I have picked up where he left off, porting his patches to the latest mainline kernel and adding support more file systems. This patch series adds a kernel interface to fs/aio.c so that kernel code can issue concurrent asynchronous IO to file systems. It adds an aio command and file system methods which specify io memory with pages instead of userspace addresses. This series was written to reduce the current overhead loop imposes by performing synchronus buffered file system IO from a kernel thread. These patches turn loop into a light weight layer that translates bios into iocbs. I note that there is no support for XFS in this patch set. Is there a particular problem that prevents XFS from being converted, or it just hasn't been done? Cheers, Dave. -- Dave Chinner da...@fromorbit.com -- 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 00/22] loop: Issue O_DIRECT aio using bio_vec
On 10/22/2012 07:07 PM, Dave Chinner wrote: On Mon, Oct 22, 2012 at 10:15:00AM -0500, Dave Kleikamp wrote: This is the current version of the patchset I presented at the LSF-MM Summit in San Francisco in April. I apologize for letting it go so long before re-submitting. This patchset was begun by Zach Brown and was originally submitted for review in October, 2009. Feedback was positive, and I have picked up where he left off, porting his patches to the latest mainline kernel and adding support more file systems. This patch series adds a kernel interface to fs/aio.c so that kernel code can issue concurrent asynchronous IO to file systems. It adds an aio command and file system methods which specify io memory with pages instead of userspace addresses. This series was written to reduce the current overhead loop imposes by performing synchronus buffered file system IO from a kernel thread. These patches turn loop into a light weight layer that translates bios into iocbs. I note that there is no support for XFS in this patch set. Is there a particular problem that prevents XFS from being converted, or it just hasn't been done? It just hasn't been done. It wasn't one of the trivial ones so I put it off at first, and after that, it's an oversight. I'll follow up with an xfs patch for your review. Thanks, Shaggy Cheers, Dave. -- 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 00/22] loop: Issue O_DIRECT aio using bio_vec
On Mon, Oct 22, 2012 at 07:53:40PM -0500, Dave Kleikamp wrote: On 10/22/2012 07:07 PM, Dave Chinner wrote: On Mon, Oct 22, 2012 at 10:15:00AM -0500, Dave Kleikamp wrote: This is the current version of the patchset I presented at the LSF-MM Summit in San Francisco in April. I apologize for letting it go so long before re-submitting. This patchset was begun by Zach Brown and was originally submitted for review in October, 2009. Feedback was positive, and I have picked up where he left off, porting his patches to the latest mainline kernel and adding support more file systems. This patch series adds a kernel interface to fs/aio.c so that kernel code can issue concurrent asynchronous IO to file systems. It adds an aio command and file system methods which specify io memory with pages instead of userspace addresses. This series was written to reduce the current overhead loop imposes by performing synchronus buffered file system IO from a kernel thread. These patches turn loop into a light weight layer that translates bios into iocbs. I note that there is no support for XFS in this patch set. Is there a particular problem that prevents XFS from being converted, or it just hasn't been done? It just hasn't been done. It wasn't one of the trivial ones so I put it off at first, and after that, it's an oversight. I'll follow up with an xfs patch for your review. Thanks Shaggy, that's all I wanted to know. No extra work for me (apart from review and testing) is fine by me. ;) Cheers, Dave. -- Dave Chinner da...@fromorbit.com -- 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/
