Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2013-01-08 Thread OGAWA Hirofumi
"Darrick J. Wong" writes: > On Fri, Dec 28, 2012 at 06:48:35AM +0900, OGAWA Hirofumi wrote: >> "Darrick J. Wong" writes: >> >> >> I think this flag should be separated into "FS provide stable page" and >> >> "FS needs bounce buffer for stable page". >> >> >> >> My fs (I guess btrfs also)

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2013-01-08 Thread OGAWA Hirofumi
Darrick J. Wong darrick.w...@oracle.com writes: On Fri, Dec 28, 2012 at 06:48:35AM +0900, OGAWA Hirofumi wrote: Darrick J. Wong darrick.w...@oracle.com writes: I think this flag should be separated into FS provide stable page and FS needs bounce buffer for stable page. My fs (I guess

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2013-01-07 Thread Darrick J. Wong
On Fri, Dec 28, 2012 at 06:48:35AM +0900, OGAWA Hirofumi wrote: > "Darrick J. Wong" writes: > > >> I think this flag should be separated into "FS provide stable page" and > >> "FS needs bounce buffer for stable page". > >> > >> My fs (I guess btrfs also) provides stable page by better way, and

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2013-01-07 Thread Darrick J. Wong
On Fri, Dec 28, 2012 at 06:48:35AM +0900, OGAWA Hirofumi wrote: Darrick J. Wong darrick.w...@oracle.com writes: I think this flag should be separated into FS provide stable page and FS needs bounce buffer for stable page. My fs (I guess btrfs also) provides stable page by better way,

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-27 Thread OGAWA Hirofumi
"Darrick J. Wong" writes: >> I think this flag should be separated into "FS provide stable page" and >> "FS needs bounce buffer for stable page". >> >> My fs (I guess btrfs also) provides stable page by better way, and >> doesn't need to wait writeback flags too. What needs is just to avoid >>

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-27 Thread Darrick J. Wong
On Fri, Dec 28, 2012 at 04:14:49AM +0900, OGAWA Hirofumi wrote: > "Darrick J. Wong" writes: > > > diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h > > index 780d4c6..0144fbb 100644 > > --- a/include/uapi/linux/fs.h > > +++ b/include/uapi/linux/fs.h > > @@ -69,6 +69,7 @@ struct

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-27 Thread OGAWA Hirofumi
"Darrick J. Wong" writes: > diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h > index 780d4c6..0144fbb 100644 > --- a/include/uapi/linux/fs.h > +++ b/include/uapi/linux/fs.h > @@ -69,6 +69,7 @@ struct inodes_stat_t { > #define MS_REMOUNT 32 /* Alter flags of a mounted FS */

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-27 Thread OGAWA Hirofumi
Darrick J. Wong darrick.w...@oracle.com writes: diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h index 780d4c6..0144fbb 100644 --- a/include/uapi/linux/fs.h +++ b/include/uapi/linux/fs.h @@ -69,6 +69,7 @@ struct inodes_stat_t { #define MS_REMOUNT 32 /* Alter flags of a

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-27 Thread Darrick J. Wong
On Fri, Dec 28, 2012 at 04:14:49AM +0900, OGAWA Hirofumi wrote: Darrick J. Wong darrick.w...@oracle.com writes: diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h index 780d4c6..0144fbb 100644 --- a/include/uapi/linux/fs.h +++ b/include/uapi/linux/fs.h @@ -69,6 +69,7 @@

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-27 Thread OGAWA Hirofumi
Darrick J. Wong darrick.w...@oracle.com writes: I think this flag should be separated into FS provide stable page and FS needs bounce buffer for stable page. My fs (I guess btrfs also) provides stable page by better way, and doesn't need to wait writeback flags too. What needs is just to

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-17 Thread Darrick J. Wong
On Mon, Dec 17, 2012 at 11:23:59AM +0100, Jan Kara wrote: > On Thu 13-12-12 00:08:11, Darrick J. Wong wrote: > > Several complaints have been received regarding long file write latencies > > when > > memory pages must be held stable during writeback. Since it might not be > > acceptable to stall

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-17 Thread Darrick J. Wong
On Mon, Dec 17, 2012 at 12:13:36AM +0800, Zheng Liu wrote: > On Thu, Dec 13, 2012 at 12:08:11AM -0800, Darrick J. Wong wrote: > > diff --git a/mm/bounce.c b/mm/bounce.c > > index 0420867..fa11935 100644 > > --- a/mm/bounce.c > > +++ b/mm/bounce.c > > @@ -178,6 +178,38 @@ static void

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-17 Thread Darrick J. Wong
On Fri, Dec 14, 2012 at 06:06:50PM -0800, Andy Lutomirski wrote: > On Fri, Dec 14, 2012 at 6:01 PM, Darrick J. Wong > wrote: > > On Fri, Dec 14, 2012 at 05:12:37PM -0800, Andy Lutomirski wrote: > >> It survived. I hit at least one mm bug, but I really don't think it's > >> a problem with your

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-17 Thread Jan Kara
On Thu 13-12-12 00:08:11, Darrick J. Wong wrote: > Several complaints have been received regarding long file write latencies when > memory pages must be held stable during writeback. Since it might not be > acceptable to stall programs for the entire duration of a page write (which > may > take

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-17 Thread Darrick J. Wong
On Fri, Dec 14, 2012 at 06:06:50PM -0800, Andy Lutomirski wrote: On Fri, Dec 14, 2012 at 6:01 PM, Darrick J. Wong darrick.w...@oracle.com wrote: On Fri, Dec 14, 2012 at 05:12:37PM -0800, Andy Lutomirski wrote: It survived. I hit at least one mm bug, but I really don't think it's a problem

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-17 Thread Darrick J. Wong
On Mon, Dec 17, 2012 at 12:13:36AM +0800, Zheng Liu wrote: On Thu, Dec 13, 2012 at 12:08:11AM -0800, Darrick J. Wong wrote: diff --git a/mm/bounce.c b/mm/bounce.c index 0420867..fa11935 100644 --- a/mm/bounce.c +++ b/mm/bounce.c @@ -178,6 +178,38 @@ static void

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-17 Thread Darrick J. Wong
On Mon, Dec 17, 2012 at 11:23:59AM +0100, Jan Kara wrote: On Thu 13-12-12 00:08:11, Darrick J. Wong wrote: Several complaints have been received regarding long file write latencies when memory pages must be held stable during writeback. Since it might not be acceptable to stall programs

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-17 Thread Jan Kara
On Thu 13-12-12 00:08:11, Darrick J. Wong wrote: Several complaints have been received regarding long file write latencies when memory pages must be held stable during writeback. Since it might not be acceptable to stall programs for the entire duration of a page write (which may take many

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-16 Thread Zheng Liu
On Thu, Dec 13, 2012 at 12:08:11AM -0800, Darrick J. Wong wrote: > diff --git a/mm/bounce.c b/mm/bounce.c > index 0420867..fa11935 100644 > --- a/mm/bounce.c > +++ b/mm/bounce.c > @@ -178,6 +178,38 @@ static void bounce_end_io_read_isa(struct bio *bio, int > err) > __bounce_end_io_read(bio,

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-16 Thread Zheng Liu
On Thu, Dec 13, 2012 at 12:08:11AM -0800, Darrick J. Wong wrote: diff --git a/mm/bounce.c b/mm/bounce.c index 0420867..fa11935 100644 --- a/mm/bounce.c +++ b/mm/bounce.c @@ -178,6 +178,38 @@ static void bounce_end_io_read_isa(struct bio *bio, int err) __bounce_end_io_read(bio,

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-14 Thread Andy Lutomirski
On Fri, Dec 14, 2012 at 6:01 PM, Darrick J. Wong wrote: > On Fri, Dec 14, 2012 at 05:12:37PM -0800, Andy Lutomirski wrote: >> It survived. I hit at least one mm bug, but I really don't think it's >> a problem with your code. (I have not tried this workload on Linux >> 3.7 at all before. It

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-14 Thread Darrick J. Wong
On Fri, Dec 14, 2012 at 05:12:37PM -0800, Andy Lutomirski wrote: > On Thu, Dec 13, 2012 at 6:10 PM, Darrick J. Wong > wrote: > > On Thu, Dec 13, 2012 at 05:48:06PM -0800, Andy Lutomirski wrote: > >> On 12/13/2012 12:08 AM, Darrick J. Wong wrote: > >> > Several complaints have been received

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-14 Thread Andy Lutomirski
On Thu, Dec 13, 2012 at 6:10 PM, Darrick J. Wong wrote: > On Thu, Dec 13, 2012 at 05:48:06PM -0800, Andy Lutomirski wrote: >> On 12/13/2012 12:08 AM, Darrick J. Wong wrote: >> > Several complaints have been received regarding long file write latencies >> > when >> > memory pages must be held

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-14 Thread Darrick J. Wong
On Fri, Dec 14, 2012 at 02:33:34PM +1100, Dave Chinner wrote: > On Thu, Dec 13, 2012 at 06:10:49PM -0800, Darrick J. Wong wrote: > > On Thu, Dec 13, 2012 at 05:48:06PM -0800, Andy Lutomirski wrote: > > > On 12/13/2012 12:08 AM, Darrick J. Wong wrote: > > > > Several complaints have been received

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-14 Thread Darrick J. Wong
On Fri, Dec 14, 2012 at 02:33:34PM +1100, Dave Chinner wrote: On Thu, Dec 13, 2012 at 06:10:49PM -0800, Darrick J. Wong wrote: On Thu, Dec 13, 2012 at 05:48:06PM -0800, Andy Lutomirski wrote: On 12/13/2012 12:08 AM, Darrick J. Wong wrote: Several complaints have been received regarding

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-14 Thread Andy Lutomirski
On Thu, Dec 13, 2012 at 6:10 PM, Darrick J. Wong darrick.w...@oracle.com wrote: On Thu, Dec 13, 2012 at 05:48:06PM -0800, Andy Lutomirski wrote: On 12/13/2012 12:08 AM, Darrick J. Wong wrote: Several complaints have been received regarding long file write latencies when memory pages must

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-14 Thread Darrick J. Wong
On Fri, Dec 14, 2012 at 05:12:37PM -0800, Andy Lutomirski wrote: On Thu, Dec 13, 2012 at 6:10 PM, Darrick J. Wong darrick.w...@oracle.com wrote: On Thu, Dec 13, 2012 at 05:48:06PM -0800, Andy Lutomirski wrote: On 12/13/2012 12:08 AM, Darrick J. Wong wrote: Several complaints have been

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-14 Thread Andy Lutomirski
On Fri, Dec 14, 2012 at 6:01 PM, Darrick J. Wong darrick.w...@oracle.com wrote: On Fri, Dec 14, 2012 at 05:12:37PM -0800, Andy Lutomirski wrote: It survived. I hit at least one mm bug, but I really don't think it's a problem with your code. (I have not tried this workload on Linux 3.7 at all

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-13 Thread Dave Chinner
On Thu, Dec 13, 2012 at 06:10:49PM -0800, Darrick J. Wong wrote: > On Thu, Dec 13, 2012 at 05:48:06PM -0800, Andy Lutomirski wrote: > > On 12/13/2012 12:08 AM, Darrick J. Wong wrote: > > > Several complaints have been received regarding long file write latencies > > > when > > > memory pages must

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-13 Thread Darrick J. Wong
On Thu, Dec 13, 2012 at 05:48:06PM -0800, Andy Lutomirski wrote: > On 12/13/2012 12:08 AM, Darrick J. Wong wrote: > > Several complaints have been received regarding long file write latencies > > when > > memory pages must be held stable during writeback. Since it might not be > > acceptable to

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-13 Thread Andy Lutomirski
On 12/13/2012 12:08 AM, Darrick J. Wong wrote: > Several complaints have been received regarding long file write latencies when > memory pages must be held stable during writeback. Since it might not be > acceptable to stall programs for the entire duration of a page write (which > may > take

[PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-13 Thread Darrick J. Wong
Several complaints have been received regarding long file write latencies when memory pages must be held stable during writeback. Since it might not be acceptable to stall programs for the entire duration of a page write (which may take many milliseconds even on good hardware), enable a second

[PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-13 Thread Darrick J. Wong
Several complaints have been received regarding long file write latencies when memory pages must be held stable during writeback. Since it might not be acceptable to stall programs for the entire duration of a page write (which may take many milliseconds even on good hardware), enable a second

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-13 Thread Andy Lutomirski
On 12/13/2012 12:08 AM, Darrick J. Wong wrote: Several complaints have been received regarding long file write latencies when memory pages must be held stable during writeback. Since it might not be acceptable to stall programs for the entire duration of a page write (which may take many

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-13 Thread Darrick J. Wong
On Thu, Dec 13, 2012 at 05:48:06PM -0800, Andy Lutomirski wrote: On 12/13/2012 12:08 AM, Darrick J. Wong wrote: Several complaints have been received regarding long file write latencies when memory pages must be held stable during writeback. Since it might not be acceptable to stall

Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write

2012-12-13 Thread Dave Chinner
On Thu, Dec 13, 2012 at 06:10:49PM -0800, Darrick J. Wong wrote: On Thu, Dec 13, 2012 at 05:48:06PM -0800, Andy Lutomirski wrote: On 12/13/2012 12:08 AM, Darrick J. Wong wrote: Several complaints have been received regarding long file write latencies when memory pages must be held