Re: [1/1] Block device throttling [Re: Distributed storage.]

2007-09-01 Thread Daniel Phillips
On Friday 31 August 2007 14:41, Alasdair G Kergon wrote: > On Thu, Aug 30, 2007 at 04:20:35PM -0700, Daniel Phillips wrote: > > Resubmitting a bio or submitting a dependent bio from > > inside a block driver does not need to be throttled because all > > resources required to guarantee completion

Re: [1/1] Block device throttling [Re: Distributed storage.]

2007-09-01 Thread Daniel Phillips
On Friday 31 August 2007 14:41, Alasdair G Kergon wrote: On Thu, Aug 30, 2007 at 04:20:35PM -0700, Daniel Phillips wrote: Resubmitting a bio or submitting a dependent bio from inside a block driver does not need to be throttled because all resources required to guarantee completion must

Re: [1/1] Block device throttling [Re: Distributed storage.]

2007-08-31 Thread Alasdair G Kergon
On Thu, Aug 30, 2007 at 04:20:35PM -0700, Daniel Phillips wrote: > Resubmitting a bio or submitting a dependent bio from > inside a block driver does not need to be throttled because all > resources required to guarantee completion must have been obtained > _before_ the bio was allowed to

Re: [1/1] Block device throttling [Re: Distributed storage.]

2007-08-31 Thread Evgeniy Polyakov
Hi Daniel. On Thu, Aug 30, 2007 at 04:20:35PM -0700, Daniel Phillips ([EMAIL PROTECTED]) wrote: > On Wednesday 29 August 2007 01:53, Evgeniy Polyakov wrote: > > Then, if of course you will want, which I doubt, you can reread > > previous mails and find that it was pointed to that race and > >

Re: [1/1] Block device throttling [Re: Distributed storage.]

2007-08-31 Thread Evgeniy Polyakov
Hi Daniel. On Thu, Aug 30, 2007 at 04:20:35PM -0700, Daniel Phillips ([EMAIL PROTECTED]) wrote: On Wednesday 29 August 2007 01:53, Evgeniy Polyakov wrote: Then, if of course you will want, which I doubt, you can reread previous mails and find that it was pointed to that race and

Re: [1/1] Block device throttling [Re: Distributed storage.]

2007-08-31 Thread Alasdair G Kergon
On Thu, Aug 30, 2007 at 04:20:35PM -0700, Daniel Phillips wrote: Resubmitting a bio or submitting a dependent bio from inside a block driver does not need to be throttled because all resources required to guarantee completion must have been obtained _before_ the bio was allowed to proceed

Re: [1/1] Block device throttling [Re: Distributed storage.]

2007-08-30 Thread Daniel Phillips
On Wednesday 29 August 2007 01:53, Evgeniy Polyakov wrote: > Then, if of course you will want, which I doubt, you can reread > previous mails and find that it was pointed to that race and > possibilities to solve it way too long ago. What still bothers me about your response is that, while you

Re: [1/1] Block device throttling [Re: Distributed storage.]

2007-08-30 Thread Daniel Phillips
On Wednesday 29 August 2007 01:53, Evgeniy Polyakov wrote: Then, if of course you will want, which I doubt, you can reread previous mails and find that it was pointed to that race and possibilities to solve it way too long ago. What still bothers me about your response is that, while you know

Re: [1/1] Block device throttling [Re: Distributed storage.]

2007-08-29 Thread Evgeniy Polyakov
On Tue, Aug 28, 2007 at 02:08:04PM -0700, Daniel Phillips ([EMAIL PROTECTED]) wrote: > On Tuesday 28 August 2007 10:54, Evgeniy Polyakov wrote: > > On Tue, Aug 28, 2007 at 10:27:59AM -0700, Daniel Phillips ([EMAIL > > PROTECTED]) wrote: > > > > We do not care about one cpu being able to increase

Re: [1/1] Block device throttling [Re: Distributed storage.]

2007-08-29 Thread Evgeniy Polyakov
On Tue, Aug 28, 2007 at 02:08:04PM -0700, Daniel Phillips ([EMAIL PROTECTED]) wrote: On Tuesday 28 August 2007 10:54, Evgeniy Polyakov wrote: On Tue, Aug 28, 2007 at 10:27:59AM -0700, Daniel Phillips ([EMAIL PROTECTED]) wrote: We do not care about one cpu being able to increase its

Re: [1/1] Block device throttling [Re: Distributed storage.]

2007-08-28 Thread Daniel Phillips
On Tuesday 28 August 2007 10:54, Evgeniy Polyakov wrote: > On Tue, Aug 28, 2007 at 10:27:59AM -0700, Daniel Phillips ([EMAIL PROTECTED]) > wrote: > > > We do not care about one cpu being able to increase its counter > > > higher than the limit, such inaccuracy (maximum bios in flight > > > thus

Re: [1/1] Block device throttling [Re: Distributed storage.]

2007-08-28 Thread Evgeniy Polyakov
On Tue, Aug 28, 2007 at 10:27:59AM -0700, Daniel Phillips ([EMAIL PROTECTED]) wrote: > > We do not care about one cpu being able to increase its counter > > higher than the limit, such inaccuracy (maximum bios in flight thus > > can be more than limit, difference is equal to the number of CPUs -

Re: [1/1] Block device throttling [Re: Distributed storage.]

2007-08-28 Thread Daniel Phillips
On Tuesday 28 August 2007 02:35, Evgeniy Polyakov wrote: > On Mon, Aug 27, 2007 at 02:57:37PM -0700, Daniel Phillips ([EMAIL PROTECTED]) wrote: > > Say Evgeniy, something I was curious about but forgot to ask you > > earlier... > > > > On Wednesday 08 August 2007 03:17, Evgeniy Polyakov wrote: >

Re: [1/1] Block device throttling [Re: Distributed storage.]

2007-08-28 Thread Evgeniy Polyakov
On Mon, Aug 27, 2007 at 02:57:37PM -0700, Daniel Phillips ([EMAIL PROTECTED]) wrote: > Say Evgeniy, something I was curious about but forgot to ask you > earlier... > > On Wednesday 08 August 2007 03:17, Evgeniy Polyakov wrote: > > ...All oerations are not atomic, since we do not care about

Re: [1/1] Block device throttling [Re: Distributed storage.]

2007-08-28 Thread Evgeniy Polyakov
On Mon, Aug 27, 2007 at 02:57:37PM -0700, Daniel Phillips ([EMAIL PROTECTED]) wrote: Say Evgeniy, something I was curious about but forgot to ask you earlier... On Wednesday 08 August 2007 03:17, Evgeniy Polyakov wrote: ...All oerations are not atomic, since we do not care about precise

Re: [1/1] Block device throttling [Re: Distributed storage.]

2007-08-28 Thread Evgeniy Polyakov
On Tue, Aug 28, 2007 at 10:27:59AM -0700, Daniel Phillips ([EMAIL PROTECTED]) wrote: We do not care about one cpu being able to increase its counter higher than the limit, such inaccuracy (maximum bios in flight thus can be more than limit, difference is equal to the number of CPUs - 1)

Re: [1/1] Block device throttling [Re: Distributed storage.]

2007-08-28 Thread Daniel Phillips
On Tuesday 28 August 2007 02:35, Evgeniy Polyakov wrote: On Mon, Aug 27, 2007 at 02:57:37PM -0700, Daniel Phillips ([EMAIL PROTECTED]) wrote: Say Evgeniy, something I was curious about but forgot to ask you earlier... On Wednesday 08 August 2007 03:17, Evgeniy Polyakov wrote: ...All

Re: [1/1] Block device throttling [Re: Distributed storage.]

2007-08-28 Thread Daniel Phillips
On Tuesday 28 August 2007 10:54, Evgeniy Polyakov wrote: On Tue, Aug 28, 2007 at 10:27:59AM -0700, Daniel Phillips ([EMAIL PROTECTED]) wrote: We do not care about one cpu being able to increase its counter higher than the limit, such inaccuracy (maximum bios in flight thus can be more

Re: [1/1] Block device throttling [Re: Distributed storage.]

2007-08-27 Thread Daniel Phillips
Say Evgeniy, something I was curious about but forgot to ask you earlier... On Wednesday 08 August 2007 03:17, Evgeniy Polyakov wrote: > ...All oerations are not atomic, since we do not care about precise > number of bios, but a fact, that we are close or close enough to the > limit. > ... in

Re: [1/1] Block device throttling [Re: Distributed storage.]

2007-08-27 Thread Daniel Phillips
Say Evgeniy, something I was curious about but forgot to ask you earlier... On Wednesday 08 August 2007 03:17, Evgeniy Polyakov wrote: ...All oerations are not atomic, since we do not care about precise number of bios, but a fact, that we are close or close enough to the limit. ... in

Re: [1/1] Block device throttling [Re: Distributed storage.]

2007-08-13 Thread Evgeniy Polyakov
Hi Daniel. On Sun, Aug 12, 2007 at 04:16:10PM -0700, Daniel Phillips ([EMAIL PROTECTED]) wrote: > Your patch is close to the truth, but it needs to throttle at the top > (virtual) end of each block device stack instead of the bottom > (physical) end. It does head in the direction of

Re: [1/1] Block device throttling [Re: Distributed storage.]

2007-08-13 Thread Evgeniy Polyakov
Hi Daniel. On Sun, Aug 12, 2007 at 04:16:10PM -0700, Daniel Phillips ([EMAIL PROTECTED]) wrote: Your patch is close to the truth, but it needs to throttle at the top (virtual) end of each block device stack instead of the bottom (physical) end. It does head in the direction of eliminating

Re: [1/1] Block device throttling [Re: Distributed storage.]

2007-08-12 Thread Daniel Phillips
Hi Evgeniy, Sorry for not getting back to you right away, I was on the road with limited email access. Incidentally, the reason my mails to you keep bouncing is, your MTA is picky about my mailer's IP reversing to a real hostname. I will take care of that pretty soon, but for now my direct

Re: [1/1] Block device throttling [Re: Distributed storage.]

2007-08-12 Thread Daniel Phillips
Hi Evgeniy, Sorry for not getting back to you right away, I was on the road with limited email access. Incidentally, the reason my mails to you keep bouncing is, your MTA is picky about my mailer's IP reversing to a real hostname. I will take care of that pretty soon, but for now my direct

Re: [1/1] Block device throttling [Re: Distributed storage.]

2007-08-08 Thread Evgeniy Polyakov
On Wed, Aug 08, 2007 at 02:17:09PM +0400, Evgeniy Polyakov ([EMAIL PROTECTED]) wrote: > This throttling mechanism allows to limit maximum amount of queued bios > per physical device. By default it is turned off and old block layer > behaviour with unlimited number of bios is used. When turned

[1/1] Block device throttling [Re: Distributed storage.]

2007-08-08 Thread Evgeniy Polyakov
This throttling mechanism allows to limit maximum amount of queued bios per physical device. By default it is turned off and old block layer behaviour with unlimited number of bios is used. When turned on (queue limit is set to something different than -1U via blk_set_queue_limit()),

[1/1] Block device throttling [Re: Distributed storage.]

2007-08-08 Thread Evgeniy Polyakov
This throttling mechanism allows to limit maximum amount of queued bios per physical device. By default it is turned off and old block layer behaviour with unlimited number of bios is used. When turned on (queue limit is set to something different than -1U via blk_set_queue_limit()),

Re: [1/1] Block device throttling [Re: Distributed storage.]

2007-08-08 Thread Evgeniy Polyakov
On Wed, Aug 08, 2007 at 02:17:09PM +0400, Evgeniy Polyakov ([EMAIL PROTECTED]) wrote: This throttling mechanism allows to limit maximum amount of queued bios per physical device. By default it is turned off and old block layer behaviour with unlimited number of bios is used. When turned on