* [PATCH] xen:rtds: Update last_start whenever cur_budget is updated @ 2016-10-26 19:06 Meng Xu 2016-10-27 9:14 ` Dario Faggioli 0 siblings, 1 reply; 6+ messages in thread From: Meng Xu @ 2016-10-26 19:06 UTC (permalink / raw) To: xen-devel Cc: Wei Liu, Dagaen Golomb, George Dunlap, Haoran Li, Dario Faggioli, Linh Thi Xuan Phan, Meng Xu, Meng Xu, Tianyang Chen We keep last_start updated whenever cur_budget is updated. This avoids subtle bugs in case burn_budget() will be called in other places in the future. Signed-off-by: Meng Xu <mengxu@cis.upenn.edu> --- Cc: Dario Faggioli <dario.faggioli@citrix.com> Cc: George Dunlap <George.Dunlap@eu.citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: Linh Thi Xuan Phan <linhphan@cis.upenn.edu> Cc: Haoran Li <lihaoran@wustl.edu> Cc: Meng Xu <xumengpanda@gmail.com> Cc: Dagaen Golomb <dgolomb@cis.upenn.edu> Cc: Tianyang Chen <tiche@cis.upenn.edu> --- xen/common/sched_rt.c | 1 + 1 file changed, 1 insertion(+) diff --git a/xen/common/sched_rt.c b/xen/common/sched_rt.c index 4b4f232..434b773 100644 --- a/xen/common/sched_rt.c +++ b/xen/common/sched_rt.c @@ -953,6 +953,7 @@ burn_budget(const struct scheduler *ops, struct rt_vcpu *svc, s_time_t now) } svc->cur_budget -= delta; + svc->last_start = now; if ( svc->cur_budget <= 0 ) { -- 1.9.1 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] xen:rtds: Update last_start whenever cur_budget is updated 2016-10-26 19:06 [PATCH] xen:rtds: Update last_start whenever cur_budget is updated Meng Xu @ 2016-10-27 9:14 ` Dario Faggioli 2016-10-27 10:03 ` Wei Liu 0 siblings, 1 reply; 6+ messages in thread From: Dario Faggioli @ 2016-10-27 9:14 UTC (permalink / raw) To: Meng Xu, xen-devel Cc: Wei Liu, Dagaen Golomb, George Dunlap, Haoran Li, Linh Thi Xuan Phan, Meng Xu, Tianyang Chen [-- Attachment #1.1: Type: text/plain, Size: 1146 bytes --] On Wed, 2016-10-26 at 15:06 -0400, Meng Xu wrote: > We keep last_start updated whenever cur_budget is updated. > This avoids subtle bugs in case burn_budget() will be called > in other places in the future. > I'd change this into something like: "Make budget accounting code more consistent by making sure the values used to compute how much budget has been consumed are updated together. This makes code resilient to calling burn_budget() from more than just one place --in case we will need to do that-- without risking subtle bugs." Also, when that is the case, like here, you need to explicitly state that no functional changes are intended. With all this done to the changelog: > Signed-off-by: Meng Xu <mengxu@cis.upenn.edu> > Acked-by: Dario Faggioli <dario.faggioli@citrix.com> This can go in 4.8, but can also well wait for 4.9. Regards, Dario -- <<This happens because I choose it to happen!>> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) [-- Attachment #1.2: This is a digitally signed message part --] [-- Type: application/pgp-signature, Size: 819 bytes --] [-- Attachment #2: Type: text/plain, Size: 127 bytes --] _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] xen:rtds: Update last_start whenever cur_budget is updated 2016-10-27 9:14 ` Dario Faggioli @ 2016-10-27 10:03 ` Wei Liu 2016-10-27 13:40 ` Meng Xu 2016-10-27 13:42 ` Meng Xu 0 siblings, 2 replies; 6+ messages in thread From: Wei Liu @ 2016-10-27 10:03 UTC (permalink / raw) To: Dario Faggioli Cc: Wei Liu, Dagaen Golomb, George Dunlap, Haoran Li, Linh Thi Xuan Phan, Meng Xu, Meng Xu, xen-devel, Tianyang Chen On Thu, Oct 27, 2016 at 11:14:36AM +0200, Dario Faggioli wrote: > On Wed, 2016-10-26 at 15:06 -0400, Meng Xu wrote: > > We keep last_start updated whenever cur_budget is updated. > > This avoids subtle bugs in case burn_budget() will be called > > in other places in the future. > > > I'd change this into something like: > > "Make budget accounting code more consistent by making sure the values > used to compute how much budget has been consumed are updated together. > > This makes code resilient to calling burn_budget() from more than just > one place --in case we will need to do that-- without risking subtle > bugs." > > Also, when that is the case, like here, you need to explicitly state > that no functional changes are intended. > > With all this done to the changelog: > > > Signed-off-by: Meng Xu <mengxu@cis.upenn.edu> > > > Acked-by: Dario Faggioli <dario.faggioli@citrix.com> > > This can go in 4.8, but can also well wait for 4.9. > Meng, let me know if you're OK with Dario's suggestion. Wei. > Regards, > Dario > -- > <<This happens because I choose it to happen!>> (Raistlin Majere) > ----------------------------------------------------------------- > Dario Faggioli, Ph.D, http://about.me/dario.faggioli > Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] xen:rtds: Update last_start whenever cur_budget is updated 2016-10-27 10:03 ` Wei Liu @ 2016-10-27 13:40 ` Meng Xu 2016-10-27 13:42 ` Meng Xu 1 sibling, 0 replies; 6+ messages in thread From: Meng Xu @ 2016-10-27 13:40 UTC (permalink / raw) To: Wei Liu Cc: Dagaen Golomb, George Dunlap, Haoran Li, Dario Faggioli, Linh Thi Xuan Phan, xen-devel@lists.xenproject.org, Tianyang Chen Hi Wei and Dario, On Thu, Oct 27, 2016 at 6:03 AM, Wei Liu <wei.liu2@citrix.com> wrote: > On Thu, Oct 27, 2016 at 11:14:36AM +0200, Dario Faggioli wrote: >> On Wed, 2016-10-26 at 15:06 -0400, Meng Xu wrote: >> > We keep last_start updated whenever cur_budget is updated. >> > This avoids subtle bugs in case burn_budget() will be called >> > in other places in the future. >> > >> I'd change this into something like: >> >> "Make budget accounting code more consistent by making sure the values >> used to compute how much budget has been consumed are updated together. >> >> This makes code resilient to calling burn_budget() from more than just >> one place --in case we will need to do that-- without risking subtle >> bugs." I agree. >> >> Also, when that is the case, like here, you need to explicitly state >> that no functional changes are intended. >> >> With all this done to the changelog: >> >> > Signed-off-by: Meng Xu <mengxu@cis.upenn.edu> >> > >> Acked-by: Dario Faggioli <dario.faggioli@citrix.com> >> >> This can go in 4.8, but can also well wait for 4.9. >> > > Meng, let me know if you're OK with Dario's suggestion. > > Wei. > >> Regards, >> Dario >> -- >> <<This happens because I choose it to happen!>> (Raistlin Majere) >> ----------------------------------------------------------------- >> Dario Faggioli, Ph.D, http://about.me/dario.faggioli >> Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) > > -- ----------- Meng Xu PhD Student in Computer and Information Science University of Pennsylvania http://www.cis.upenn.edu/~mengxu/ _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] xen:rtds: Update last_start whenever cur_budget is updated 2016-10-27 10:03 ` Wei Liu 2016-10-27 13:40 ` Meng Xu @ 2016-10-27 13:42 ` Meng Xu 2016-10-27 13:43 ` Wei Liu 1 sibling, 1 reply; 6+ messages in thread From: Meng Xu @ 2016-10-27 13:42 UTC (permalink / raw) To: Wei Liu Cc: Dagaen Golomb, George Dunlap, Haoran Li, Dario Faggioli, Linh Thi Xuan Phan, xen-devel@lists.xenproject.org, Tianyang Chen Sorry, I accidentally sent out the previous email... On Thu, Oct 27, 2016 at 6:03 AM, Wei Liu <wei.liu2@citrix.com> wrote: > On Thu, Oct 27, 2016 at 11:14:36AM +0200, Dario Faggioli wrote: >> On Wed, 2016-10-26 at 15:06 -0400, Meng Xu wrote: >> > We keep last_start updated whenever cur_budget is updated. >> > This avoids subtle bugs in case burn_budget() will be called >> > in other places in the future. >> > >> I'd change this into something like: >> >> "Make budget accounting code more consistent by making sure the values >> used to compute how much budget has been consumed are updated together. >> >> This makes code resilient to calling burn_budget() from more than just >> one place --in case we will need to do that-- without risking subtle >> bugs." >> Agree. >> Also, when that is the case, like here, you need to explicitly state >> that no functional changes are intended. As Dario suggested, it's better to add one more line in the change log "No functional changes are intended." >> >> With all this done to the changelog: >> >> > Signed-off-by: Meng Xu <mengxu@cis.upenn.edu> >> > >> Acked-by: Dario Faggioli <dario.faggioli@citrix.com> >> >> This can go in 4.8, but can also well wait for 4.9. Agree.. >> > > Meng, let me know if you're OK with Dario's suggestion. I'm OK with his suggestion. I can send out a new patch with the new commit change log, if needed. Thanks, Meng -- ------------ Meng Xu PhD Student in Computer and Information Science University of Pennsylvania http://www.cis.upenn.edu/~mengxu/ _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] xen:rtds: Update last_start whenever cur_budget is updated 2016-10-27 13:42 ` Meng Xu @ 2016-10-27 13:43 ` Wei Liu 0 siblings, 0 replies; 6+ messages in thread From: Wei Liu @ 2016-10-27 13:43 UTC (permalink / raw) To: Meng Xu Cc: Wei Liu, Dagaen Golomb, George Dunlap, Haoran Li, Dario Faggioli, Linh Thi Xuan Phan, xen-devel@lists.xenproject.org, Tianyang Chen On Thu, Oct 27, 2016 at 09:42:56AM -0400, Meng Xu wrote: > Sorry, I accidentally sent out the previous email... > > On Thu, Oct 27, 2016 at 6:03 AM, Wei Liu <wei.liu2@citrix.com> wrote: > > On Thu, Oct 27, 2016 at 11:14:36AM +0200, Dario Faggioli wrote: > >> On Wed, 2016-10-26 at 15:06 -0400, Meng Xu wrote: > >> > We keep last_start updated whenever cur_budget is updated. > >> > This avoids subtle bugs in case burn_budget() will be called > >> > in other places in the future. > >> > > >> I'd change this into something like: > >> > >> "Make budget accounting code more consistent by making sure the values > >> used to compute how much budget has been consumed are updated together. > >> > >> This makes code resilient to calling burn_budget() from more than just > >> one place --in case we will need to do that-- without risking subtle > >> bugs." > >> > > Agree. > > >> Also, when that is the case, like here, you need to explicitly state > >> that no functional changes are intended. > > As Dario suggested, it's better to add one more line in the change log > "No functional changes are intended." > > >> > >> With all this done to the changelog: > >> > >> > Signed-off-by: Meng Xu <mengxu@cis.upenn.edu> > >> > > >> Acked-by: Dario Faggioli <dario.faggioli@citrix.com> > >> > >> This can go in 4.8, but can also well wait for 4.9. > > Agree.. > > >> > > > > Meng, let me know if you're OK with Dario's suggestion. > > I'm OK with his suggestion. > I can send out a new patch with the new commit change log, if needed. > No need. I will fix it up. Wei. > Thanks, > > Meng > > -- > ------------ > Meng Xu > PhD Student in Computer and Information Science > University of Pennsylvania > http://www.cis.upenn.edu/~mengxu/ _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2016-10-27 13:45 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2016-10-26 19:06 [PATCH] xen:rtds: Update last_start whenever cur_budget is updated Meng Xu 2016-10-27 9:14 ` Dario Faggioli 2016-10-27 10:03 ` Wei Liu 2016-10-27 13:40 ` Meng Xu 2016-10-27 13:42 ` Meng Xu 2016-10-27 13:43 ` Wei Liu
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