On Fri, 2009-03-13 at 12:46 -0700, Yinghai Lu wrote: > Jaswinder Singh Rajput wrote: > > On Fri, 2009-03-13 at 21:03 +0530, Jaswinder Singh Rajput wrote: > >> On Fri, 2009-03-13 at 02:34 +0000, Yinghai Lu wrote: > >>> Commit-ID: 8ad9790588ee2e69118b2b294ddab6f3f0379ad9 > >>> Gitweb: http://git.kernel.org/tip/8ad9790588ee2e69118b2b294ddab6f3f0379ad9 > >>> Author: Yinghai Lu <yinghai@xxxxxxxxxx> > >>> AuthorDate: Thu, 12 Mar 2009 18:43:54 -0700 > >>> Commit: Ingo Molnar <mingo@xxxxxxx> > >>> CommitDate: Fri, 13 Mar 2009 02:52:18 +0100 > >>> > >>> x86: more MTRR debug printouts > >>> > >>> Impact: improve MTRR debugging messages > >>> > >>> There's still inefficiencies suspected with the MTRR sanitizing > >>> code, so make sure we get all the info we need from a dmesg. > >>> > >>> - Remove unneeded mtrr_show > >>> > >>> (It will only printout one time by first cpu, so it is no big deal.) > >>> > >>> - Also print out directly from get_mtrr, because it doesn't update mtrr_state. > >>> > >>> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx> > >>> LKML-Reference: <49B9BA5A.40108@xxxxxxxxxx> > >>> Signed-off-by: Ingo Molnar <mingo@xxxxxxx> > >>> > >>> > >>> *base = 0; > >>> @@ -407,6 +410,10 @@ static void generic_get_mtrr(unsigned int reg, unsigned long *base, > >>> *size = -mask_lo; > >>> *base = base_hi << (32 - PAGE_SHIFT) | base_lo >> PAGE_SHIFT; > >>> *type = base_lo & 0xff; > >>> + > >>> + printk(KERN_DEBUG " get_mtrr: cpu%d reg%02d base=%010lx size=%010lx %s\n", > >>> + smp_processor_id(), reg, *base, *size, > >>> + mtrr_attrib_to_str(*type & 0xff)); > >>> } > >>> > >> This leads to: > >> > >> Kernel failure message 1: > >> BUG: using smp_processor_id() in preemptible [00000000] code: Xorg/1983 > >> caller is generic_get_mtrr+0x12a/0x146 > >> Pid: 1983, comm: Xorg Not tainted 2.6.29-rc8-tip #81 SMP PREEMPT Fri Mar > >> 13 20:43:36 IST 2009 > >> Call Trace: > >> [<c0412cc3>] ? printk+0x14/0x16 > >> [<c02357e3>] debug_smp_processor_id+0xbb/0xd4 > >> [<c010f0c3>] generic_get_mtrr+0x12a/0x146 > >> [<c010e351>] mtrr_add_page+0x154/0x332 > >> [<c010e7b1>] mtrr_file_add+0x72/0x86 > >> [<c010e9e0>] mtrr_ioctl+0x21b/0x309 > >> [<c01bc07d>] proc_reg_unlocked_ioctl+0x67/0xb2 > >> [<c010e7c5>] ? mtrr_ioctl+0x0/0x309 > >> [<c01bc016>] ? proc_reg_unlocked_ioctl+0x0/0xb2 > >> [<c0194101>] vfs_ioctl+0x27/0x6e > >> [<c0194680>] do_vfs_ioctl+0x46f/0x4a9 > >> [<c017bfa5>] ? do_mmap_pgoff+0x1e3/0x22e > >> [<c01898b0>] ? fget_light+0x40/0x130 > >> [<c01946ee>] sys_ioctl+0x34/0x61 > >> [<c0102c73>] sysenter_do_call+0x12/0x25 > >> > > please check > > [PATCH] x86: fix get_mtrr warning about smp_processor_id with preempt > > Impact: fix warning > > Jaswinder noticed that there is warning about smp_processor_id() in get_mtrr > > try to fix it by use disable/enable to wrap it. > > Reported-by: Jaswinder Singh Rajput <jaswinder@xxxxxxxxxx> > Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx> Thanks, this fix the bug. But I am still not happy with ruining dmesg, It looks weird on 2 cpu box, what will be the case for 16 or more cpus. We are supporting these output in /sys/kernel/x86/cpu/cpu*/mtrr/mtrr through cpu_debug.c, why do not you use it and only flush this information on panic: [ 0.000000] last_pfn = 0x3ff2f max_arch_pfn = 0x100000 [ 0.000000] MTRR default type: uncachable [ 0.000000] MTRR fixed ranges enabled: [ 0.000000] 00000-0FFFF write-back [ 0.000000] 10000-1FFFF write-back [ 0.000000] 20000-2FFFF write-back [ 0.000000] 30000-3FFFF write-back [ 0.000000] 40000-4FFFF write-back [ 0.000000] 50000-5FFFF write-back [ 0.000000] 60000-6FFFF write-back [ 0.000000] 70000-7FFFF write-back [ 0.000000] 80000-83FFF write-back [ 0.000000] 84000-87FFF write-back [ 0.000000] 88000-8BFFF write-back [ 0.000000] 8C000-8FFFF write-back [ 0.000000] 90000-93FFF write-back [ 0.000000] 94000-97FFF write-back [ 0.000000] 98000-9BFFF write-back [ 0.000000] 9C000-9FFFF write-back [ 0.000000] A0000-A3FFF uncachable [ 0.000000] A4000-A7FFF uncachable [ 0.000000] A8000-ABFFF uncachable [ 0.000000] AC000-AFFFF uncachable [ 0.000000] B0000-B3FFF uncachable [ 0.000000] B4000-B7FFF uncachable [ 0.000000] B8000-BBFFF uncachable [ 0.000000] BC000-BFFFF uncachable [ 0.000000] C0000-C0FFF uncachable [ 0.000000] C1000-C1FFF uncachable [ 0.000000] C2000-C2FFF uncachable [ 0.000000] C3000-C3FFF uncachable [ 0.000000] C4000-C4FFF uncachable [ 0.000000] C5000-C5FFF uncachable [ 0.000000] C6000-C6FFF uncachable [ 0.000000] C7000-C7FFF uncachable [ 0.000000] C8000-C8FFF uncachable [ 0.000000] C9000-C9FFF uncachable [ 0.000000] CA000-CAFFF uncachable [ 0.000000] CB000-CBFFF uncachable [ 0.000000] CC000-CCFFF uncachable [ 0.000000] CD000-CDFFF uncachable [ 0.000000] CE000-CEFFF uncachable [ 0.000000] CF000-CFFFF uncachable [ 0.000000] D0000-D0FFF uncachable [ 0.000000] D1000-D1FFF uncachable [ 0.000000] D2000-D2FFF uncachable [ 0.000000] D3000-D3FFF uncachable [ 0.000000] D4000-D4FFF uncachable [ 0.000000] D5000-D5FFF uncachable [ 0.000000] D6000-D6FFF uncachable [ 0.000000] D7000-D7FFF uncachable [ 0.000000] D8000-D8FFF uncachable [ 0.000000] D9000-D9FFF uncachable [ 0.000000] DA000-DAFFF uncachable [ 0.000000] DB000-DBFFF uncachable [ 0.000000] DC000-DCFFF uncachable [ 0.000000] DD000-DDFFF uncachable [ 0.000000] DE000-DEFFF uncachable [ 0.000000] DF000-DFFFF uncachable [ 0.000000] E0000-E0FFF uncachable [ 0.000000] E1000-E1FFF uncachable [ 0.000000] E2000-E2FFF uncachable [ 0.000000] E3000-E3FFF uncachable [ 0.000000] E4000-E4FFF uncachable [ 0.000000] E5000-E5FFF uncachable [ 0.000000] E6000-E6FFF uncachable [ 0.000000] E7000-E7FFF uncachable [ 0.000000] E8000-E8FFF uncachable [ 0.000000] E9000-E9FFF uncachable [ 0.000000] EA000-EAFFF uncachable [ 0.000000] EB000-EBFFF uncachable [ 0.000000] EC000-ECFFF uncachable [ 0.000000] ED000-EDFFF uncachable [ 0.000000] EE000-EEFFF uncachable [ 0.000000] EF000-EFFFF uncachable [ 0.000000] F0000-F0FFF write-protect [ 0.000000] F1000-F1FFF write-protect [ 0.000000] F2000-F2FFF write-protect [ 0.000000] F3000-F3FFF write-protect [ 0.000000] F4000-F4FFF write-protect [ 0.000000] F5000-F5FFF write-protect [ 0.000000] F6000-F6FFF write-protect [ 0.000000] F7000-F7FFF write-protect [ 0.000000] F8000-F8FFF write-protect [ 0.000000] F9000-F9FFF write-protect [ 0.000000] FA000-FAFFF write-protect [ 0.000000] FB000-FBFFF write-protect [ 0.000000] FC000-FCFFF write-protect [ 0.000000] FD000-FDFFF write-protect [ 0.000000] FE000-FEFFF write-protect [ 0.000000] FF000-FFFFF write-protect [ 0.000000] MTRR variable ranges enabled: [ 0.000000] 0 base 000000000 mask FC0000000 write-back [ 0.000000] 1 disabled [ 0.000000] 2 disabled [ 0.000000] 3 disabled [ 0.000000] 4 disabled [ 0.000000] 5 disabled [ 0.000000] 6 disabled [ 0.000000] 7 disabled [ 0.000000] x86 PAT enabled: cpu 0, old 0x7040600070406, new 0x7010600070106 [ 0.000000] get_mtrr: cpu0 reg00 base=0000000000 size=0000040000 write-back .. [ 32.112812] get_mtrr: cpu1 reg00 base=0000000000 size=0000040000 write-back [ 32.112822] get_mtrr: cpu1 reg01 base=00000f8000 size=0000004000 write-combining [ 32.112874] get_mtrr: cpu1 reg00 base=0000000000 size=0000040000 write-back [ 32.112881] get_mtrr: cpu1 reg01 base=00000f8000 size=0000004000 write-combining [ 32.121742] get_mtrr: cpu1 reg00 base=0000000000 size=0000040000 write-back [ 32.121749] get_mtrr: cpu1 reg01 base=00000f8000 size=0000004000 write-combining [ 32.138014] get_mtrr: cpu1 reg00 base=0000000000 size=0000040000 write-back [ 32.138021] get_mtrr: cpu1 reg01 base=00000f8000 size=0000004000 write-combining [ 32.138028] get_mtrr: cpu1 reg00 base=0000000000 size=0000040000 write-back [ 32.138033] get_mtrr: cpu1 reg01 base=00000f8000 size=0000004000 write-combining [ 32.138660] get_mtrr: cpu1 reg02 base=00000e0000 size=0000010000 write-combining [ 32.139246] get_mtrr: cpu1 reg00 base=0000000000 size=0000040000 write-back [ 32.139284] get_mtrr: cpu1 reg01 base=00000f8000 size=0000004000 write-combining [ 32.139297] get_mtrr: cpu1 reg00 base=0000000000 size=0000040000 write-back [ 32.139307] get_mtrr: cpu1 reg01 base=00000f8000 size=0000004000 write-combining [ 32.139996] get_mtrr: cpu1 reg02 base=00000e0000 size=0000010000 write-combining [ 32.306889] get_mtrr: cpu1 reg00 base=0000000000 size=0000040000 write-back [ 32.306899] get_mtrr: cpu1 reg01 base=00000f8000 size=0000004000 write-combining [ 32.313545] get_mtrr: cpu1 reg00 base=0000000000 size=0000040000 write-back [ 32.313551] get_mtrr: cpu1 reg01 base=00000f8000 size=0000004000 write-combining [ 32.313558] get_mtrr: cpu1 reg00 base=0000000000 size=0000040000 write-back [ 32.313563] get_mtrr: cpu1 reg01 base=00000f8000 size=0000004000 write-combining [ 32.317551] get_mtrr: cpu1 reg00 base=0000000000 size=0000040000 write-back [ 32.317559] get_mtrr: cpu1 reg01 base=00000f8000 size=0000004000 write-combining [ 32.317565] get_mtrr: cpu1 reg02 base=00000e0000 size=0000008000 write-combining [ 32.389848] get_mtrr: cpu1 reg00 base=0000000000 size=0000040000 write-back [ 32.389856] get_mtrr: cpu1 reg01 base=00000f8000 size=0000004000 write-combining [ 32.389860] get_mtrr: cpu1 reg02 base=00000e0000 size=0000008000 write-combining [ 32.390449] get_mtrr: cpu1 reg02 base=00000e0000 size=0000010000 write-combining [ 32.390591] get_mtrr: cpu1 reg00 base=0000000000 size=0000040000 write-back [ 32.390601] get_mtrr: cpu1 reg01 base=00000f8000 size=0000004000 write-combining [ 32.390610] get_mtrr: cpu1 reg02 base=00000e0000 size=0000010000 write-combining [ 32.390648] get_mtrr: cpu1 reg02 base=00000e0000 size=0000010000 write-combining [ 32.390710] get_mtrr: cpu1 reg00 base=0000000000 size=0000040000 write-back [ 32.390715] get_mtrr: cpu1 reg01 base=00000f8000 size=0000004000 write-combining [ 32.390720] get_mtrr: cpu1 reg02 base=00000e0000 size=0000010000 write-combining -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html