From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH] xen/arm: Fix rtds scheduler for arm Date: Fri, 30 Jan 2015 16:10:45 +0000 Message-ID: <54CBAD05.10800@linaro.org> References: <54CB8958020000780005B464@mail.emea.novell.com> <1422632449-23130-1-git-send-email-denys.drozdov@globallogic.com> <54CBA76E.4010808@linaro.org> <54CBA9C4.4070305@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <54CBA9C4.4070305@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: Andrew Cooper , Denis Drozdov , JBeulich@suse.com, xen-devel@lists.xen.org, george.dunlap@eu.citrix.com List-Id: xen-devel@lists.xenproject.org On 30/01/15 15:56, Andrew Cooper wrote: > On 30/01/15 15:46, Julien Grall wrote: >> Hello Denys, >> >> On 30/01/15 15:40, Denis Drozdov wrote: >>> From: denys drozdov >>> >>> Update RT scheduler to run on arm platform >> You need to give more background of the problem (i.e why you have to >> disable the IRQ on ARM). >> >> As the scheduler is common with x86, I would expect the problem is also >> happening on this architecture. > > Changing a spinlock_irq into an irqsave is safe, functionally speaking, > but it is concerning that the scheduler appears to be called in > different interrupt states between architectures. For instance credit2 is also using vcpu_schedule_lock_irq... Although, IIRC, it's not used by default. So it has to be fixed too on ARM. In any case, the commit message needs more background such as stack trace and/or explaining why we have to take spinlock_irq. This may also need to document context_saved to explain the IRQs may not be enabled when this function is called. Regards, -- Julien Grall