From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH v3 18/18] xen/arm: IRQ: Handle multiple action per IRQ Date: Thu, 17 Apr 2014 13:35:56 +0100 Message-ID: <534FCAAC.4070807@linaro.org> References: <1396968247-8768-1-git-send-email-julien.grall@linaro.org> <1396968247-8768-19-git-send-email-julien.grall@linaro.org> <1397663693.24638.226.camel@kazak.uk.xensource.com> <534EAA6C.9070601@linaro.org> <1397665048.24638.237.camel@kazak.uk.xensource.com> <534EAE7C.7090609@linaro.org> <534F99C90200007800009DAE@nat28.tlf.novell.com> <534FAEC6.9070303@linaro.org> <534FD3FB0200007800009F41@nat28.tlf.novell.com> <534FB985.7010606@linaro.org> <1397734580.24638.297.camel@kazak.uk.xensource.com> <534FC67E.3010602@linaro.org> <1397737620.24638.298.camel@kazak.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta4.messagelabs.com ([85.158.143.247]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1WalXs-0006j6-37 for xen-devel@lists.xenproject.org; Thu, 17 Apr 2014 12:36:00 +0000 Received: by mail-ee0-f41.google.com with SMTP id t10so629279eei.28 for ; Thu, 17 Apr 2014 05:35:58 -0700 (PDT) In-Reply-To: <1397737620.24638.298.camel@kazak.uk.xensource.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: Ian Campbell Cc: xen-devel@lists.xenproject.org, Keir Fraser , stefano.stabellini@citrix.com, Jan Beulich , tim@xen.org List-Id: xen-devel@lists.xenproject.org On 04/17/2014 01:27 PM, Ian Campbell wrote: > On Thu, 2014-04-17 at 13:18 +0100, Julien Grall wrote: >> On 04/17/2014 12:36 PM, Ian Campbell wrote: >>> On Thu, 2014-04-17 at 12:22 +0100, Julien Grall wrote: >>>> On 04/17/2014 12:15 PM, Jan Beulich wrote: >>>>>>>> On 17.04.14 at 12:36, wrote: >>>>>> In Linux case, they are safe because they are using a single linked list. >>>>> >>>>> And is there a strong reason for us to use a doubly linked one? >>>> >>>> My first version was single-linked list... Ian asked me to use generic >>>> list on V1 to avoid open code. >>> >>> I also suggested that you could import a single linked list >>> implementation if you thought it would be better. >>> >>>> I was looking to port llist.h from Linux but it seems a bit overkill for >>>> action list. >>> >>> I don't see why. I'm sure there are other potential uses of singly >>> linked lists which people just used a double list because it was simpler >>> at the time. >> >> >> They are using xchg and AFAIU it's not possible to delete an element >> anywhere in the list. See: >> >> http://lxr.free-electrons.com/source/include/linux/llist.h > > Hrm, I thought Linux had a standard singly link list available too, oh > well. > > Another option would be to delete things using the rcu mechanisms > perhaps. Ok. Unless if you strongly disagree, I will stick into the "next" field. Using rcu... doesn't seems the right things for an IRQ management code. -- Julien Grall