Do I remember that there was a patch for the spinlock code to allow measuring lock contention? Maybe from Jan? If so, where might I find it? Thanks, Dan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
I don''t remember such a patch. Depending on what stats you want, it probably wouldn''t be hard to knock something up? -- Keir On 07/04/2009 16:56, "Dan Magenheimer" <dan.magenheimer@oracle.com> wrote:> Do I remember that there was a patch for the spinlock > code to allow measuring lock contention? Maybe from > Jan? If so, where might I find it? > > Thanks, > Dan > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
> I don''t remember such a patch.Hmmm... maybe it was a patch in xenlinux?> probably wouldn''t be hard to knock something up?Maybe if I were an x86 assembly guru ;-)> Depending on what stats you wantMaybe incrementing a (64-bit) counter, some debug key to print out all counters, and some way to register a lock to put it in the debug-key list? Maybe enable this code by default whenever debug is enabled (but it might be useful data in the wild too).> -----Original Message----- > From: Keir Fraser [mailto:keir.fraser@eu.citrix.com] > Sent: Tuesday, April 07, 2009 11:11 AM > To: Dan Magenheimer; Xen-Devel (E-mail) > Subject: Re: [Xen-devel] lock contention measuring code? > > > I don''t remember such a patch. Depending on what stats you > want, it probably > wouldn''t be hard to knock something up? > > -- Keir > > On 07/04/2009 16:56, "Dan Magenheimer" > <dan.magenheimer@oracle.com> wrote: > > > Do I remember that there was a patch for the spinlock > > code to allow measuring lock contention? Maybe from > > Jan? If so, where might I find it? > > > > Thanks, > > Dan > > > > _______________________________________________ > > Xen-devel mailing list > > Xen-devel@lists.xensource.com > > http://lists.xensource.com/xen-devel > > >_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On 07/04/2009 19:41, "Dan Magenheimer" <dan.magenheimer@oracle.com> wrote:>> I don''t remember such a patch. > > Hmmm... maybe it was a patch in xenlinux? > >> probably wouldn''t be hard to knock something up? > > Maybe if I were an x86 assembly guru ;-)It doesn''t need to be done in assembly code. The spinlock C functions are all in C file common/spinlock.c and all the try-and-spin logic is implemented in C now. Only try-to-take-lock and unlock are in asm. -- Keir _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Dan Magenheimer wrote:>> I don''t remember such a patch. >> > > Hmmm... maybe it was a patch in xenlinux? >Aside from all the normal tools in mainline (which are extensive), the Xen PV spinlock code is also well instrumented. J _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel