Tony, I tried your latest branch: devel-smp-on-unicore, kernel boots up but got lots of WARN_ON fired: --- ------------[ cut here ]------------ [ 1.149719] WARNING: at mm/percpu-vm.c:320 pcpu_alloc+0x2fc/0x888() [ 1.149780] Modules linked in: [ 1.149841] [<c01b34c8>] (unwind_backtrace+0x0/0xe4) from [<c01e939c>] (warn_slowpath_common+0x4c/0x64) [ 1.149902] [<c01e939c>] (warn_slowpath_common+0x4c/0x64) from [<c01e93cc>] (warn_slowpath_null+0x18/0x1c) [ 1.149993] [<c01e93cc>] (warn_slowpath_null+0x18/0x1c) from [<c0274730>] (pcpu_alloc+0x2fc/0x888) [ 1.150085] [<c0274730>] (pcpu_alloc+0x2fc/0x888) from [<c0279578>] (sget+0x198/0x43c) [ 1.150146] [<c0279578>] (sget+0x198/0x43c) from [<c0279adc>] (get_sb_ns+0x20/0x90) [ 1.150238] [<c0279adc>] (get_sb_ns+0x20/0x90) from [<c02791a4>] (vfs_kern_mount+0x9c/0x18c) [ 1.150299] [<c02791a4>] (vfs_kern_mount+0x9c/0x18c) from [<c0022280>] (init_mqueue_fs+0x68/0xc8) [ 1.150390] [<c0022280>] (init_mqueue_fs+0x68/0xc8) from [<c01ac5d0>] (do_one_initcall+0xcc/0x1a4) [ 1.150451] [<c01ac5d0>] (do_one_initcall+0xcc/0x1a4) from [<c0008760>] (kernel_init+0x148/0x210) [ 1.150543] [<c0008760>] (kernel_init+0x148/0x210) from [<c01adcf8>] (kernel_thread_exit+0x0/0x8) [ 1.150604] ---[ end trace 1b75b31a2719ed74 ]--- --- It looks like we still missed to set some flag for chuck. -Bryan On Fri, Sep 3, 2010 at 8:09 PM, Shilimkar, Santosh <santosh.shilimkar@xxxxxx> wrote: > > >> -----Original Message----- >> From: linux-omap-owner@xxxxxxxxxxxxxxx [mailto:linux-omap- >> owner@xxxxxxxxxxxxxxx] On Behalf Of Tony Lindgren >> Sent: Thursday, September 02, 2010 11:13 PM >> To: Russell King - ARM Linux >> Cc: linux-omap@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; >> Bryan Wu; Will Deacon >> Subject: Re: [PATCH 1/6] ARM: Add inline function smp_on_up() for early >> init testing >> >> * Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx> [100902 10:00]: >> > On Thu, Sep 02, 2010 at 09:18:47AM -0700, Tony Lindgren wrote: >> > >> > > --- a/arch/arm/include/asm/smp_plat.h >> > > +++ b/arch/arm/include/asm/smp_plat.h >> > > @@ -39,4 +39,20 @@ static inline int cache_ops_need_broadcast(void) >> > > #define UP(instr...) _str(instr) >> > > #endif >> > > >> > > +static inline int smp_on_up(void) >> > > +{ >> > > +#ifdef CONFIG_SMP_ON_UP >> > > + int smp_on_up; >> > > + >> > > + asm( \ >> > > + SMP(mov %0, #0) \ >> > > + UP(mov %0, #1) \ >> > > + : "=r" (smp_on_up)); >> > > + >> > > + return smp_on_up; >> > > +#else >> > > + return 0; >> > > +#endif >> > >> > I think this is the wrong approach - rather than a function which tells >> us >> > just if we are a SMP kernel running on UP, why not something which >> returns >> > whether we're running on SMP and use that to eliminate some of these >> ifdefs? >> >> Sure. Will has something like this in his patches: >> >> static inline int cpu_is_part_of_mp_system(void) >> { >> u32 mpidr; >> asm volatile("mrc p15, 0, %0, c0, c0, 5" : "=r" (mpidr)); >> return (mpidr >> 31) ? !(mpidr >> 30) : 0; >> } > > I guess this register is only available on MP Core extensions. > > Regards, > Santosh > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
