From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oren Laadan Subject: Re: [RFC PATCH 11/17] define function to print error messages to user log Date: Thu, 29 Oct 2009 12:02:40 -0400 Message-ID: <4AE9BCA0.6090209@librato.com> References: <1256683587-23961-1-git-send-email-serge@us.ibm.com> <1256683587-23961-12-git-send-email-serge@us.ibm.com> <20091028181415.GB14023@count0.beaverton.ibm.com> <20091028205424.GA27394@us.ibm.com> <4AE8BCB5.4030406@librato.com> <20091028221208.GA30227@us.ibm.com> <4AE8C639.6090105@librato.com> <20091029001223.GA1463@us.ibm.com> <4AE8E578.4030300@librato.com> <20091029042304.GA9005@hallyn.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20091029042304.GA9005-A9i7LUbDfNHQT0dZR+AlfA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: "Serge E. Hallyn" Cc: containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org List-Id: containers.vger.kernel.org Serge E. Hallyn wrote: > Quoting Oren Laadan (orenl-RdfvBDnrOixBDgjK7y7TUQ@public.gmane.org): >> >> Serge E. Hallyn wrote: >>> Quoting Oren Laadan (orenl-RdfvBDnrOixBDgjK7y7TUQ@public.gmane.org): >>>> Serge E. Hallyn wrote: >>>>> Quoting Oren Laadan (orenl-RdfvBDnrOixBDgjK7y7TUQ@public.gmane.org): >>>>>> Serge E. Hallyn wrote: >>>>>>> Quoting Matt Helsley (matthltc-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org): >>>>>>>>> @@ -401,6 +409,9 @@ char *ckpt_generate_fmt(struct ckpt_ctx *ctx, char *fmt) >>>>>>>>> case 'E': >>>>>>>>> len += sprintf(format+len, "[%s]", "err %d"); >>>>>>>>> break; >>>>>>>>> + case 'C': /* count of bytes read/written to checkpoint image */ >>>>>>>>> + len += sprintf(format+len, "[%s]", "pos %d"); >>>>>>>>> + break; >>>>>>>> Instead we could always output ckpt->total and then we wouldn't need %(C). I >>>>>>>> suspect it's such a useful piece of information that it'll be repeated >>>>>>>> in many/all format strings eventually. >>>>>>> Yes, likewise %(T). If that's what we want to do. >>>>>> I agree. For the cases when there is not task, can put "none" >>>>>> >>>>>>> Should we discuss here what we want an entry to look like? For both >>>>>>> ckpt_write_err (to the checkpoint image) and ckpt_error()? >>>>>>> >>>>>> Yes please ! >>>>> Actually %T isn't the current task, right, so it shouldn't always be prepended? >>>>> It actually is only meaningful during checkpoint_task(), collect_objs(), and >>>>> __tree_count_tasks? >>>>> >>>>> Ok, so how about: >>>>> >>>>> 1. ckpt_write_err() always also calls ckpt_error() (which in turn calls >>>>> ckpt_debug). Avoid duplication which exists in several places >>>>> right now. >>>>> 2. We always prepend: >>>>> >>>>> [current->pid]:[ctx->root_pid]:[ctx->active_pid]:[ctx->errno][ctx->total] >>>>> >>>>> The %(X) expansions if specified come whereever they are in the fmt >>>>> string (which is what's happening now with my patchset). >>>> So somewhere should set ctx->errno during a checkpoint. >>>> >>>> I suppose active_pid is for restart, but it's redundant isn't it ? >>>> (it's always active_pid) - is it the different between top-level pid-ns >>>> and "current" pid-ns ? >>> No, I figured it would be meaningful for instance in places like >>> wait_task_active(). >> Perhaps then leave it out of the default printing, and have the >> specific debug messages there write it explicitly. > > Ok, so then current suggested format looks like: > > [current->pid]:[ctx->errno]:[ctx->total] > > Though is ctx->errno helpful even in restart? Or should we assume we'll > figure that out through the msg in restore_notify_error()? > > Maybe do: > [current->pid]=[task_pid_vnr(current)]:[ctx->total] I think errno is only helpful if an error occured. So it should definitely be a part of the default msg given by ckpt_error(), but not otherwise. Oren.