Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-31 Thread Srivatsa Vaddagiri
On Thu, May 31, 2007 at 02:15:34AM -0700, William Lee Irwin III wrote: > Yes, the larger number of schedulable entities and hence slower > convergence to groupwise weightings is a disadvantage of the flattening. > A hybrid scheme seems reasonable enough. Cool! This puts me back on track to

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-31 Thread William Lee Irwin III
On Thu, May 31, 2007 at 02:03:53PM +0530, Srivatsa Vaddagiri wrote: >> Its ->wait_runtime will drop less significantly, which lets it be >> inserted in rb-tree much to the left of those 1000 tasks (and which >> indirectly lets it gain back its fair share during subsequent >> schedule cycles). >>

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-31 Thread Srivatsa Vaddagiri
On Thu, May 31, 2007 at 02:03:53PM +0530, Srivatsa Vaddagiri wrote: > Its ->wait_runtime will drop less significantly, which lets it be > inserted in rb-tree much to the left of those 1000 tasks (and which indirectly > lets it gain back its fair share during subsequent schedule cycles). > > Hmm

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-31 Thread William Lee Irwin III
On Wed, May 30, 2007 at 11:36:47PM -0700, William Lee Irwin III wrote: >> Temporarily, yes. All this only works when averaged out. On Thu, May 31, 2007 at 02:03:53PM +0530, Srivatsa Vaddagiri wrote: > So essentially when we calculate delta_mine component for each of those > 1000 tasks, we will

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-31 Thread Srivatsa Vaddagiri
On Wed, May 30, 2007 at 11:36:47PM -0700, William Lee Irwin III wrote: > On Thu, May 31, 2007 at 11:18:28AM +0530, Srivatsa Vaddagiri wrote: > > Hmm ..the fact that each task runs for a minimum of 1 tick seems to > > complicate the matters to me (when doing group fairness given a single > > level

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-31 Thread William Lee Irwin III
On Wed, May 30, 2007 at 09:09:26PM -0700, William Lee Irwin III wrote: >> It's not all that tricky. On Thu, May 31, 2007 at 11:18:28AM +0530, Srivatsa Vaddagiri wrote: > Hmm ..the fact that each task runs for a minimum of 1 tick seems to > complicate the matters to me (when doing group fairness

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-31 Thread William Lee Irwin III
On Wed, May 30, 2007 at 09:09:26PM -0700, William Lee Irwin III wrote: It's not all that tricky. On Thu, May 31, 2007 at 11:18:28AM +0530, Srivatsa Vaddagiri wrote: Hmm ..the fact that each task runs for a minimum of 1 tick seems to complicate the matters to me (when doing group fairness

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-31 Thread Srivatsa Vaddagiri
On Wed, May 30, 2007 at 11:36:47PM -0700, William Lee Irwin III wrote: On Thu, May 31, 2007 at 11:18:28AM +0530, Srivatsa Vaddagiri wrote: Hmm ..the fact that each task runs for a minimum of 1 tick seems to complicate the matters to me (when doing group fairness given a single level

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-31 Thread William Lee Irwin III
On Wed, May 30, 2007 at 11:36:47PM -0700, William Lee Irwin III wrote: Temporarily, yes. All this only works when averaged out. On Thu, May 31, 2007 at 02:03:53PM +0530, Srivatsa Vaddagiri wrote: So essentially when we calculate delta_mine component for each of those 1000 tasks, we will find

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-31 Thread Srivatsa Vaddagiri
On Thu, May 31, 2007 at 02:03:53PM +0530, Srivatsa Vaddagiri wrote: Its -wait_runtime will drop less significantly, which lets it be inserted in rb-tree much to the left of those 1000 tasks (and which indirectly lets it gain back its fair share during subsequent schedule cycles). Hmm ..is

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-31 Thread William Lee Irwin III
On Thu, May 31, 2007 at 02:03:53PM +0530, Srivatsa Vaddagiri wrote: Its -wait_runtime will drop less significantly, which lets it be inserted in rb-tree much to the left of those 1000 tasks (and which indirectly lets it gain back its fair share during subsequent schedule cycles). Hmm ..is

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-31 Thread Srivatsa Vaddagiri
On Thu, May 31, 2007 at 02:15:34AM -0700, William Lee Irwin III wrote: Yes, the larger number of schedulable entities and hence slower convergence to groupwise weightings is a disadvantage of the flattening. A hybrid scheme seems reasonable enough. Cool! This puts me back on track to

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-30 Thread Srivatsa Vaddagiri
On Wed, May 30, 2007 at 09:09:26PM -0700, William Lee Irwin III wrote: > It's not all that tricky. Hmm ..the fact that each task runs for a minimum of 1 tick seems to complicate the matters to me (when doing group fairness given a single level hierarchy). A user with 1000 (or more) tasks can be

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-30 Thread William Lee Irwin III
On Wed, May 30, 2007 at 01:13:59PM -0700, William Lee Irwin III wrote: >> The step beyond was to show how nice numbers can be done with all that >> hierarchical task grouping so they have global effects instead of >> effects limited to the scope of the narrowest grouping hierarchy >> containing

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-30 Thread Srivatsa Vaddagiri
On Wed, May 30, 2007 at 01:13:59PM -0700, William Lee Irwin III wrote: > On Wed, May 30, 2007 at 10:44:05PM +0530, Srivatsa Vaddagiri wrote: > > Hmm ..so do you think this weight decomposition can be used to flatten > > the tree all the way to a single level in case of cfs? That would mean we > >

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-30 Thread William Lee Irwin III
On Sat, May 26, 2007 at 08:41:12AM -0700, William Lee Irwin III wrote: >> The smpnice affair is better phrased in terms of task weighting. It's >> simple to honor nice in such an arrangement. First unravel the >> grouping hierarchy, then weight by nice. This looks like [...] >> conveniently

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-30 Thread Srivatsa Vaddagiri
On Sat, May 26, 2007 at 08:41:12AM -0700, William Lee Irwin III wrote: > The smpnice affair is better phrased in terms of task weighting. It's > simple to honor nice in such an arrangement. First unravel the > grouping hierarchy, then weight by nice. This looks like > > tasknicehier1

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-30 Thread William Lee Irwin III
On Sat, May 26, 2007 at 08:41:12AM -0700, William Lee Irwin III wrote: The smpnice affair is better phrased in terms of task weighting. It's simple to honor nice in such an arrangement. First unravel the grouping hierarchy, then weight by nice. This looks like [...] conveniently collapse to

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-30 Thread Srivatsa Vaddagiri
On Wed, May 30, 2007 at 01:13:59PM -0700, William Lee Irwin III wrote: On Wed, May 30, 2007 at 10:44:05PM +0530, Srivatsa Vaddagiri wrote: Hmm ..so do you think this weight decomposition can be used to flatten the tree all the way to a single level in case of cfs? That would mean we can

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-30 Thread William Lee Irwin III
On Wed, May 30, 2007 at 01:13:59PM -0700, William Lee Irwin III wrote: The step beyond was to show how nice numbers can be done with all that hierarchical task grouping so they have global effects instead of effects limited to the scope of the narrowest grouping hierarchy containing the task.

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-30 Thread Srivatsa Vaddagiri
On Wed, May 30, 2007 at 09:09:26PM -0700, William Lee Irwin III wrote: It's not all that tricky. Hmm ..the fact that each task runs for a minimum of 1 tick seems to complicate the matters to me (when doing group fairness given a single level hierarchy). A user with 1000 (or more) tasks can be

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-30 Thread Srivatsa Vaddagiri
On Sat, May 26, 2007 at 08:41:12AM -0700, William Lee Irwin III wrote: The smpnice affair is better phrased in terms of task weighting. It's simple to honor nice in such an arrangement. First unravel the grouping hierarchy, then weight by nice. This looks like tasknicehier1 hier2

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-29 Thread Peter Williams
William Lee Irwin III wrote: On Wed, May 30, 2007 at 10:09:28AM +1000, Peter Williams wrote: So what you're saying is that you think dynamic priority (or its equivalent) should be used for load balancing instead of static priority? It doesn't do much in other schemes, but when fairness is

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-29 Thread William Lee Irwin III
On Mon, May 28, 2007 at 10:09:19PM +0530, Srivatsa Vaddagiri wrote: > What do these task weights control? Timeslice primarily? If so, I am not > sure how well it can co-exist with cfs then (unless you are planning to > replace cfs with a equally good interactive/fair scheduler :) > I would be very

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-29 Thread William Lee Irwin III
William Lee Irwin III wrote: >> Lag is the deviation of a task's allocated CPU time from the CPU time >> it would be granted by the ideal fair scheduling algorithm (generalized >> processor sharing; take the limit of RR with per-task timeslices >> proportional to load weight as the scale factor

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-29 Thread hui
On Mon, May 28, 2007 at 10:09:19PM +0530, Srivatsa Vaddagiri wrote: > On Fri, May 25, 2007 at 10:14:58AM -0700, Li, Tong N wrote: > > is represented by a weight of 10. Inside the group, let's say the two > > tasks, P1 and P2, have weights 1 and 2. Then the system-wide weight for > > P1 is 10/3 and

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-29 Thread Peter Williams
William Lee Irwin III wrote: William Lee Irwin III wrote: Lag should be considered in lieu of load because lag On Sun, May 27, 2007 at 11:29:51AM +1000, Peter Williams wrote: What's the definition of lag here? Lag is the deviation of a task's allocated CPU time from the CPU time it would

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-29 Thread William Lee Irwin III
William Lee Irwin III wrote: >> Lag should be considered in lieu of load because lag On Sun, May 27, 2007 at 11:29:51AM +1000, Peter Williams wrote: > What's the definition of lag here? Lag is the deviation of a task's allocated CPU time from the CPU time it would be granted by the ideal fair

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-29 Thread William Lee Irwin III
William Lee Irwin III wrote: Lag should be considered in lieu of load because lag On Sun, May 27, 2007 at 11:29:51AM +1000, Peter Williams wrote: What's the definition of lag here? Lag is the deviation of a task's allocated CPU time from the CPU time it would be granted by the ideal fair

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-29 Thread Peter Williams
William Lee Irwin III wrote: William Lee Irwin III wrote: Lag should be considered in lieu of load because lag On Sun, May 27, 2007 at 11:29:51AM +1000, Peter Williams wrote: What's the definition of lag here? Lag is the deviation of a task's allocated CPU time from the CPU time it would

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-29 Thread hui
On Mon, May 28, 2007 at 10:09:19PM +0530, Srivatsa Vaddagiri wrote: On Fri, May 25, 2007 at 10:14:58AM -0700, Li, Tong N wrote: is represented by a weight of 10. Inside the group, let's say the two tasks, P1 and P2, have weights 1 and 2. Then the system-wide weight for P1 is 10/3 and the

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-29 Thread William Lee Irwin III
William Lee Irwin III wrote: Lag is the deviation of a task's allocated CPU time from the CPU time it would be granted by the ideal fair scheduling algorithm (generalized processor sharing; take the limit of RR with per-task timeslices proportional to load weight as the scale factor approaches

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-29 Thread William Lee Irwin III
On Mon, May 28, 2007 at 10:09:19PM +0530, Srivatsa Vaddagiri wrote: What do these task weights control? Timeslice primarily? If so, I am not sure how well it can co-exist with cfs then (unless you are planning to replace cfs with a equally good interactive/fair scheduler :) I would be very

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-29 Thread Peter Williams
William Lee Irwin III wrote: On Wed, May 30, 2007 at 10:09:28AM +1000, Peter Williams wrote: So what you're saying is that you think dynamic priority (or its equivalent) should be used for load balancing instead of static priority? It doesn't do much in other schemes, but when fairness is

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-28 Thread Peter Williams
Peter Williams wrote: Srivatsa Vaddagiri wrote: On Sat, May 26, 2007 at 10:17:42AM +1000, Peter Williams wrote: I don't think that ignoring cpu affinity is an option. Setting the cpu affinity of tasks is a deliberate policy action on the part of the system administrator and has to be

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-28 Thread Paul Menage
On 5/28/07, Peter Williams <[EMAIL PROTECTED]> wrote: In any case, there's no point having cpu affinity if it's going to be ignored. Maybe you could have two levels of affinity: 1. if set by a root it must be obeyed; and 2. if set by an ordinary user it can be overridden if the best interests

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-28 Thread Peter Williams
Srivatsa Vaddagiri wrote: On Sat, May 26, 2007 at 10:17:42AM +1000, Peter Williams wrote: I don't think that ignoring cpu affinity is an option. Setting the cpu affinity of tasks is a deliberate policy action on the part of the system administrator and has to be honoured. mmm ..but users

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-28 Thread Srivatsa Vaddagiri
On Sat, May 26, 2007 at 10:17:42AM +1000, Peter Williams wrote: > I don't think that ignoring cpu affinity is an option. Setting the cpu > affinity of tasks is a deliberate policy action on the part of the > system administrator and has to be honoured. mmm ..but users can set cpu affinity

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-28 Thread Srivatsa Vaddagiri
On Fri, May 25, 2007 at 10:14:58AM -0700, Li, Tong N wrote: > Nice work, Vatsa. When I wrote the DWRR algorithm, I flattened the > hierarchies into one level, so maybe that approach can be applied to > your code as well. What I did is to maintain task and task group weights > and reservations

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-28 Thread Srivatsa Vaddagiri
On Fri, May 25, 2007 at 10:14:58AM -0700, Li, Tong N wrote: Nice work, Vatsa. When I wrote the DWRR algorithm, I flattened the hierarchies into one level, so maybe that approach can be applied to your code as well. What I did is to maintain task and task group weights and reservations

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-28 Thread Srivatsa Vaddagiri
On Sat, May 26, 2007 at 10:17:42AM +1000, Peter Williams wrote: I don't think that ignoring cpu affinity is an option. Setting the cpu affinity of tasks is a deliberate policy action on the part of the system administrator and has to be honoured. mmm ..but users can set cpu affinity w/o

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-28 Thread Peter Williams
Srivatsa Vaddagiri wrote: On Sat, May 26, 2007 at 10:17:42AM +1000, Peter Williams wrote: I don't think that ignoring cpu affinity is an option. Setting the cpu affinity of tasks is a deliberate policy action on the part of the system administrator and has to be honoured. mmm ..but users

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-28 Thread Paul Menage
On 5/28/07, Peter Williams [EMAIL PROTECTED] wrote: In any case, there's no point having cpu affinity if it's going to be ignored. Maybe you could have two levels of affinity: 1. if set by a root it must be obeyed; and 2. if set by an ordinary user it can be overridden if the best interests of

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-28 Thread Peter Williams
Peter Williams wrote: Srivatsa Vaddagiri wrote: On Sat, May 26, 2007 at 10:17:42AM +1000, Peter Williams wrote: I don't think that ignoring cpu affinity is an option. Setting the cpu affinity of tasks is a deliberate policy action on the part of the system administrator and has to be

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-26 Thread Peter Williams
William Lee Irwin III wrote: Srivatsa Vaddagiri wrote: Ingo/Peter, any thoughts here? CFS and smpnice probably is "broken" with respect to such example as above albeit for nice-based tasks. On Sat, May 26, 2007 at 10:17:42AM +1000, Peter Williams wrote: See above. I think that faced with

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-26 Thread William Lee Irwin III
Srivatsa Vaddagiri wrote: >> Ingo/Peter, any thoughts here? CFS and smpnice probably is "broken" >> with respect to such example as above albeit for nice-based tasks. On Sat, May 26, 2007 at 10:17:42AM +1000, Peter Williams wrote: > See above. I think that faced with cpu affinity use by the

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-26 Thread William Lee Irwin III
Srivatsa Vaddagiri wrote: Ingo/Peter, any thoughts here? CFS and smpnice probably is broken with respect to such example as above albeit for nice-based tasks. On Sat, May 26, 2007 at 10:17:42AM +1000, Peter Williams wrote: See above. I think that faced with cpu affinity use by the system

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-26 Thread Peter Williams
William Lee Irwin III wrote: Srivatsa Vaddagiri wrote: Ingo/Peter, any thoughts here? CFS and smpnice probably is broken with respect to such example as above albeit for nice-based tasks. On Sat, May 26, 2007 at 10:17:42AM +1000, Peter Williams wrote: See above. I think that faced with cpu

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Peter Williams
Srivatsa Vaddagiri wrote: Good example :) USER2's single task will have to share its CPU with USER1's 50 tasks (unless we modify the smpnice load balancer to disregard cpu affinity that is - which I would not prefer to do). I don't think that ignoring cpu affinity is an option. Setting the

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Srivatsa Vaddagiri
On Fri, May 25, 2007 at 08:18:56PM +0400, Kirill Korotaev wrote: > 2 physical CPUs can't select the same VCPU at the same time. > i.e. VCPU can be running on 1 PCPU only at the moment. > and vice versa: PCPU can run only 1 VCPU at the given moment. > > So serialization is done when we need to

Re: [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Li, Tong N
On Fri, 2007-05-25 at 21:44 +0530, Srivatsa Vaddagiri wrote: > > > > That assumes per-user scheduling groups; other configurations would > > make it one step for each level of hierarchy. It may be possible to > > reduce those steps to only state transitions that change weightings > > and

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Kirill Korotaev
Srivatsa Vaddagiri wrote: > On Fri, May 25, 2007 at 05:05:16PM +0400, Kirill Korotaev wrote: > >>>That way the scheduler would first pick a "virtual CPU" to schedule, and >>>then pick a user from that virtual CPU, and then a task from the user. >> >>don't you mean the vice versa: >>first use to

Re: [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Srivatsa Vaddagiri
On Wed, May 23, 2007 at 11:03:16AM -0700, William Lee Irwin III wrote: > Well, SMP load balancing is what makes all this hard. Agreed. I am optimistic that we can achieve good degree of SMP fairness using similar mechanism as smpnice .. > On Wed, May 23, 2007 at 10:18:59PM +0530, Srivatsa

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Srivatsa Vaddagiri
On Fri, May 25, 2007 at 05:05:16PM +0400, Kirill Korotaev wrote: > > That way the scheduler would first pick a "virtual CPU" to schedule, and > > then pick a user from that virtual CPU, and then a task from the user. > > don't you mean the vice versa: > first use to scheduler, then VCPU (which

Re: [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Kirill Korotaev
Ingo Molnar wrote: > * Srivatsa Vaddagiri <[EMAIL PROTECTED]> wrote: > > >>Can you repeat your tests with this patch pls? With the patch applied, >>I am now getting the same split between nice 0 and nice 10 task as >>CFS-v13 provides (90:10 as reported by top ) >> >> 5418 guest 20 0

Re: [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Srivatsa Vaddagiri
On Fri, May 25, 2007 at 02:05:36PM +0200, Ingo Molnar wrote: > great. Btw., could you please keep the "up to this point there should be > no behavioral change in CFS" fundamental splitup of your patches - sure ..basically the changes required in CFS core is the introduction of two structures -

Re: [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Ingo Molnar
* Srivatsa Vaddagiri <[EMAIL PROTECTED]> wrote: > On Fri, May 25, 2007 at 01:11:40PM +0200, Ingo Molnar wrote: > > > I was planning on reusing smpnice concepts here, with the difference > > > that we balance group weights across CPU in addition to total weight > > > of CPUs. > > > > ok, that

Re: [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Srivatsa Vaddagiri
On Fri, May 25, 2007 at 01:11:40PM +0200, Ingo Molnar wrote: > > I was planning on reusing smpnice concepts here, with the difference > > that we balance group weights across CPU in addition to total weight > > of CPUs. > > ok, that would be (much) simpler that any explicit vcpu approach. Do

Re: [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Ingo Molnar
* Srivatsa Vaddagiri <[EMAIL PROTECTED]> wrote: > On Fri, May 25, 2007 at 10:29:51AM +0200, Ingo Molnar wrote: > > btw., what are you thoughts about SMP? > > I was planning on reusing smpnice concepts here, with the difference > that we balance group weights across CPU in addition to total

Re: [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Srivatsa Vaddagiri
On Fri, May 25, 2007 at 10:29:51AM +0200, Ingo Molnar wrote: > btw., what are you thoughts about SMP? I was planning on reusing smpnice concepts here, with the difference that we balance group weights across CPU in addition to total weight of CPUs. For ex, assuming weight of each task is 10

Re: [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Guillaume Chazarain
Srivatsa Vaddagiri a écrit : Can you repeat your tests with this patch pls? With the patch applied, I am now getting the same split between nice 0 and nice 10 task as CFS-v13 provides (90:10 as reported by top ) Yep, this fixes the problem for me too. Thanks. -- Guillaume - To unsubscribe

Re: [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Ingo Molnar
* Srivatsa Vaddagiri <[EMAIL PROTECTED]> wrote: > Can you repeat your tests with this patch pls? With the patch applied, > I am now getting the same split between nice 0 and nice 10 task as > CFS-v13 provides (90:10 as reported by top ) > > 5418 guest 20 0 2464 304 236 R 90 0.0

Re: [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Srivatsa Vaddagiri
On Wed, May 23, 2007 at 08:32:52PM +0200, Ingo Molnar wrote: > > Here's an attempt to extend CFS (v13) to be fair at a group level, > > rather than just at task level. The patch is in a very premature state > > (passes simple tests, smp load balance not supported yet) at this > > point. I am

Re: [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Srivatsa Vaddagiri
On Thu, May 24, 2007 at 12:26:16AM +0200, Guillaume Chazarain wrote: > As a sidenote, while in CFS-v13 a nice=0 tasks seems to get 10x more CPU > than a nice=10 one, with the group fairness patch, the ratio drops to > less than 2x (for tasks with the same UID). gah ..silly me. Can you repeat

Re: [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Srivatsa Vaddagiri
On Thu, May 24, 2007 at 12:26:16AM +0200, Guillaume Chazarain wrote: As a sidenote, while in CFS-v13 a nice=0 tasks seems to get 10x more CPU than a nice=10 one, with the group fairness patch, the ratio drops to less than 2x (for tasks with the same UID). gah ..silly me. Can you repeat your

Re: [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Srivatsa Vaddagiri
On Wed, May 23, 2007 at 08:32:52PM +0200, Ingo Molnar wrote: Here's an attempt to extend CFS (v13) to be fair at a group level, rather than just at task level. The patch is in a very premature state (passes simple tests, smp load balance not supported yet) at this point. I am sending it

Re: [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Ingo Molnar
* Srivatsa Vaddagiri [EMAIL PROTECTED] wrote: Can you repeat your tests with this patch pls? With the patch applied, I am now getting the same split between nice 0 and nice 10 task as CFS-v13 provides (90:10 as reported by top ) 5418 guest 20 0 2464 304 236 R 90 0.0

Re: [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Guillaume Chazarain
Srivatsa Vaddagiri a écrit : Can you repeat your tests with this patch pls? With the patch applied, I am now getting the same split between nice 0 and nice 10 task as CFS-v13 provides (90:10 as reported by top ) Yep, this fixes the problem for me too. Thanks. -- Guillaume - To unsubscribe

Re: [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Srivatsa Vaddagiri
On Fri, May 25, 2007 at 01:11:40PM +0200, Ingo Molnar wrote: I was planning on reusing smpnice concepts here, with the difference that we balance group weights across CPU in addition to total weight of CPUs. ok, that would be (much) simpler that any explicit vcpu approach. Do you plan

Re: [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Srivatsa Vaddagiri
On Fri, May 25, 2007 at 10:29:51AM +0200, Ingo Molnar wrote: btw., what are you thoughts about SMP? I was planning on reusing smpnice concepts here, with the difference that we balance group weights across CPU in addition to total weight of CPUs. For ex, assuming weight of each task is 10

Re: [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Ingo Molnar
* Srivatsa Vaddagiri [EMAIL PROTECTED] wrote: On Fri, May 25, 2007 at 10:29:51AM +0200, Ingo Molnar wrote: btw., what are you thoughts about SMP? I was planning on reusing smpnice concepts here, with the difference that we balance group weights across CPU in addition to total weight of

Re: [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Ingo Molnar
* Srivatsa Vaddagiri [EMAIL PROTECTED] wrote: On Fri, May 25, 2007 at 01:11:40PM +0200, Ingo Molnar wrote: I was planning on reusing smpnice concepts here, with the difference that we balance group weights across CPU in addition to total weight of CPUs. ok, that would be (much)

Re: [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Srivatsa Vaddagiri
On Fri, May 25, 2007 at 02:05:36PM +0200, Ingo Molnar wrote: great. Btw., could you please keep the up to this point there should be no behavioral change in CFS fundamental splitup of your patches - sure ..basically the changes required in CFS core is the introduction of two structures -

Re: [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Kirill Korotaev
Ingo Molnar wrote: * Srivatsa Vaddagiri [EMAIL PROTECTED] wrote: Can you repeat your tests with this patch pls? With the patch applied, I am now getting the same split between nice 0 and nice 10 task as CFS-v13 provides (90:10 as reported by top ) 5418 guest 20 0 2464 304 236 R

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Srivatsa Vaddagiri
On Fri, May 25, 2007 at 05:05:16PM +0400, Kirill Korotaev wrote: That way the scheduler would first pick a virtual CPU to schedule, and then pick a user from that virtual CPU, and then a task from the user. don't you mean the vice versa: first use to scheduler, then VCPU (which is

Re: [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Srivatsa Vaddagiri
On Wed, May 23, 2007 at 11:03:16AM -0700, William Lee Irwin III wrote: Well, SMP load balancing is what makes all this hard. Agreed. I am optimistic that we can achieve good degree of SMP fairness using similar mechanism as smpnice .. On Wed, May 23, 2007 at 10:18:59PM +0530, Srivatsa

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Kirill Korotaev
Srivatsa Vaddagiri wrote: On Fri, May 25, 2007 at 05:05:16PM +0400, Kirill Korotaev wrote: That way the scheduler would first pick a virtual CPU to schedule, and then pick a user from that virtual CPU, and then a task from the user. don't you mean the vice versa: first use to scheduler, then

Re: [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Li, Tong N
On Fri, 2007-05-25 at 21:44 +0530, Srivatsa Vaddagiri wrote: That assumes per-user scheduling groups; other configurations would make it one step for each level of hierarchy. It may be possible to reduce those steps to only state transitions that change weightings and incremental

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Srivatsa Vaddagiri
On Fri, May 25, 2007 at 08:18:56PM +0400, Kirill Korotaev wrote: 2 physical CPUs can't select the same VCPU at the same time. i.e. VCPU can be running on 1 PCPU only at the moment. and vice versa: PCPU can run only 1 VCPU at the given moment. So serialization is done when we need to assign

Re: [ckrm-tech] [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-25 Thread Peter Williams
Srivatsa Vaddagiri wrote: Good example :) USER2's single task will have to share its CPU with USER1's 50 tasks (unless we modify the smpnice load balancer to disregard cpu affinity that is - which I would not prefer to do). I don't think that ignoring cpu affinity is an option. Setting the

Re: [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-23 Thread Ingo Molnar
* Srivatsa Vaddagiri <[EMAIL PROTECTED]> wrote: > Here's an attempt to extend CFS (v13) to be fair at a group level, > rather than just at task level. The patch is in a very premature state > (passes simple tests, smp load balance not supported yet) at this > point. I am sending it out early

[RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-23 Thread Srivatsa Vaddagiri
Here's an attempt to extend CFS (v13) to be fair at a group level, rather than just at task level. The patch is in a very premature state (passes simple tests, smp load balance not supported yet) at this point. I am sending it out early to know if this is a good direction to proceed. Salient

[RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-23 Thread Srivatsa Vaddagiri
Here's an attempt to extend CFS (v13) to be fair at a group level, rather than just at task level. The patch is in a very premature state (passes simple tests, smp load balance not supported yet) at this point. I am sending it out early to know if this is a good direction to proceed. Salient

Re: [RFC] [PATCH 0/3] Add group fairness to CFS

2007-05-23 Thread Ingo Molnar
* Srivatsa Vaddagiri [EMAIL PROTECTED] wrote: Here's an attempt to extend CFS (v13) to be fair at a group level, rather than just at task level. The patch is in a very premature state (passes simple tests, smp load balance not supported yet) at this point. I am sending it out early to