Re: [PATCH] xenconsole: Ensure exclusive access to console using locks

From: Martin Lucina <martin@lucina.net>
To: Ian Campbell <ian.campbell@citrix.com>
Cc: xen-devel@lists.xenproject.org,
	Ian Jackson <ian.jackson@eu.citrix.com>,
	Wei Liu <wei.liu2@citrix.com>,
	Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Subject: Re: [PATCH] xenconsole: Ensure exclusive access to console using locks
Date: Fri, 24 Jul 2015 15:40:27 +0200	[thread overview]
Message-ID: <20150724134027.GE25338@nodbug.lucina.net> (raw)
In-Reply-To: <1437743460.24746.88.camel@citrix.com>

On Friday, 24.07.2015 at 14:11, Ian Campbell wrote:
> I'm afraid this (delving into another components private headers) isn't
> allowed. Instead you should add the two lines to tools/console/Makefile
> to generate a local _paths.h:
> 
> genpath-target = $(call buildmakevars2header,_paths.h)
> $(eval $(genpath-target))
> 
> Plus a dependency on it in the xenconsole rule and a .gitignore entry.
> 
> You might want to generate client/_paths.h instead to avoid needing to
> muck around with CFLAGS.

The above works, but causes genpath-target to be re-run each time "make" is
called in tools/console, i.e. no longer says "Nothing to be done for all".
I presume that's ok?

> I think you can use string concatenation here, e.g.
>     XEN_LOCK_DIR "/xenconsole.%d"
> 
> 
> Given the known limits on the size of domid it would probably be
> possible to figure out a tighter limit than PATH_MAX.

Ok, I can just make it the usual 255 ...

Martin