From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ryan Harper Subject: Re: Possible bugs and doubts about readjusting weights/slice-lengths from command prompt Date: Wed, 3 May 2006 10:26:49 -0500 Message-ID: <20060503152649.GE16776@us.ibm.com> References: <5f74ce410605022248m31c5de98j95c2dbffd6b5878a@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <5f74ce410605022248m31c5de98j95c2dbffd6b5878a@mail.gmail.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Amitayu Das Cc: xen-devel , rhim@cc.gatech.edu List-Id: xen-devel@lists.xenproject.org * Amitayu Das [2006-05-03 00:49]: > 2. Say, I'm readjusting the slice lengths of running domains. While doing > that, I make a mistake by having sum of the slice-lengths higher than > period-length. In such cases, what does Xen actually do? I did not find > sanity-checking code for such cases in xen/common/sched_sedf.c. Please let > me know in case it's not there, why so or it's there, only I did not find > it. For time-driven domains, versus weighted domains in sched_sedf.c:1407 /* * Sanity checking: note that disabling extra weight requires * that we set a non-zero slice. */ if ( (cmd->u.sedf.period > PERIOD_MAX) || (cmd->u.sedf.period < PERIOD_MIN) || (cmd->u.sedf.slice > cmd->u.sedf.period) || (cmd->u.sedf.slice < SLICE_MIN) ) return -EINVAL; period has bounds, slice cannot be greater than period, and slice cannot be smaller than SLICE_MIN. For any of these cases, the command will not succeed. You also might be interested in looking at tools/xm-test/tests/sedf which has some simple sedf scheduler tests. > > 3. I tried to modify/readjust the slice/period length (or weights) for > domains from command prompt. However, I found out that changes are > immaterial after first attempt. That is, no matter what changes I made at > second or third or fourth time, they are not actually taking place. Only, > the changes made during the first attempt actually took place. Please let me > know if this is a bug in the existing code or I should have done the things > in a different manner. Could you supply the xm sched-sedf commands and values you used? -- Ryan Harper Software Engineer; Linux Technology Center IBM Corp., Austin, Tx (512) 838-9253 T/L: 678-9253 ryanh@us.ibm.com