On Tue, May 19, 2015 at 09:42:07AM +0100, Jan Beulich wrote: > >>> On 19.05.15 at 09:40, <chao.p.p...@linux.intel.com> wrote: > > On Mon, May 18, 2015 at 02:33:51PM +0100, Jan Beulich wrote: > >> >>> On 08.05.15 at 10:56, <chao.p.p...@linux.intel.com> wrote: > >> > +static unsigned long *__read_mostly cat_socket_init_bitmap; > >> > +static unsigned long *__read_mostly cat_socket_enable_bitmap; > >> > >> Didn't we agree to fold these two into one? Apart from that the > >> _bitmap name tag doesn't seem very useful... > > > > Looks like this? > > > > static unsigned long *__read_mostly cat_socket_init, > > *__read_mostly cat_socket_enable; > > Yes, except that you will want to drop one (or make clear why you > need both).
As said in the previous version, cat_socket_enable is the actual CAT enabled status. And cat_socket_init is used for performance optimization purpose only. It indicate if the socket has been initialized, so that initialization happens only once for each socket, but not __cpus_in_socket__ times. There are three possibilities: 1) Not initialized; 2) Initialized, CAT disabled; 3) Initialized, CAT enabled; So it's not possible to use only one bit to represent three values. > > >> > static int cpu_callback( > >> > struct notifier_block *nfb, unsigned long action, void *hcpu) > >> > { > >> > if ( action == CPU_STARTING ) > >> > psr_cpu_init(); > >> > + else if ( action == CPU_DYING ) > >> > + psr_cpu_fini(); > >> > >> Are these the right notifiers for doing things involving memory > >> allocation / freeing? > > > > psr_cpu_fini() does not really have memory allocation/freeing but > > psr_cpu_init() does have. > > Hmm, wait - where did I see this allocation? Looking again, I don't see > it now. But if there was one, then surely it would be wrong for _fini > to not free it. > > > While one thing to clarify is: psr_cpu_init() will not propagate > > the error even when the memory allocation fails(instead it disables > > the CAT on the socket). > > > > If there is still problem then perhaps I need change CPU_STARTING back > > to CPU_ONLINE and make on_selected_cpus() call on target cpu. > > No, if there was any allocation needed, you should do the allocation > in CPU_UP_PREPARE and the initialization in CPU_STARTING. But it > looks like this is moot now anyway. As I will add allocation in patch 4, so I will move psr_cpu_init() to CPU_UP_PREPARE(As the allocation length is based on the cpuid result, so the initialization will also be done here), but still need to move psr_cpu_fini(which will add the freeing code) to CPU_DOWN_PREPARE? Chao _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel