From mboxrd@z Thu Jan 1 00:00:00 1970 From: Boris Ostrovsky Subject: Re: [PATCH v2] xen/balloon: Don't continue ballooning when BP_ECANCELED is encountered Date: Thu, 09 Oct 2014 13:42:29 -0400 Message-ID: <5436C905.2090603@oracle.com> References: <1412715607-16751-1-git-send-email-boris.ostrovsky@oracle.com> <5436C343.2080102@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5436C343.2080102@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: David Vrabel , konrad.wilk@oracle.com Cc: daniel.kiper@oracle.com, xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On 10/09/2014 01:17 PM, David Vrabel wrote: > On 07/10/14 22:00, Boris Ostrovsky wrote: >> Commit 3dcf63677d4e ("xen/balloon: cancel ballooning if adding new >> memory failed") makes reserve_additional_memory() return BP_ECANCELED >> when an error is encountered. This error, however, is ignored by the >> caller (balloon_process()) since it is overwritten by subsequent call >> to update_schedule(). This results in continuous attempts to add more >> memory, all of which are likely to fail again. >> >> We should stop trying to schedule next iteration of ballooning when >> the current one has failed. > What triggers this bug? I could never work out what it was. I don't know, I haven't been able to reproduce it neither. It's clearly something in AWS. But once you hit it (which you can do by simulating add_memory() return an error) you will keep retrying, getting the same error back and flooding the log. -boris > > Applied to stable/for-linus-3.18 > > David