| Message ID | 1526278438-10519-1-git-send-email-kernelfans@gmail.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | powerpc/cpu: nr_cpu_ids should be aligned on threads_per_core | expand |
Hi Pingfan,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on powerpc/next]
[also build test ERROR on v4.17-rc5 next-20180511]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Pingfan-Liu/powerpc-cpu-nr_cpu_ids-should-be-aligned-on-threads_per_core/20180514-141629
base: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
config: powerpc-allnoconfig (attached as .config)
compiler: powerpc-linux-gnu-gcc (Debian 7.2.0-11) 7.2.0
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=powerpc
All errors (new ones prefixed by >>):
arch/powerpc/kernel/prom.c: In function 'early_init_dt_scan_cpus':
>> arch/powerpc/kernel/prom.c:370:14: error: lvalue required as left operand of assignment
nr_cpu_ids = nr_cpus_aligned;
^
vim +370 arch/powerpc/kernel/prom.c
306
307 static int __init early_init_dt_scan_cpus(unsigned long node,
308 const char *uname, int depth,
309 void *data)
310 {
311 const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
312 const __be32 *prop;
313 const __be32 *intserv;
314 int i, nthreads;
315 int len;
316 int found = -1;
317 int found_thread = 0;
318 unsigned int nr_cpus_aligned;
319
320 /* We are scanning "cpu" nodes only */
321 if (type == NULL || strcmp(type, "cpu") != 0)
322 return 0;
323
324 /* Get physical cpuid */
325 intserv = of_get_flat_dt_prop(node, "ibm,ppc-interrupt-server#s", &len);
326 if (!intserv)
327 intserv = of_get_flat_dt_prop(node, "reg", &len);
328
329 nthreads = len / sizeof(int);
330
331 /*
332 * Now see if any of these threads match our boot cpu.
333 * NOTE: This must match the parsing done in smp_setup_cpu_maps.
334 */
335 for (i = 0; i < nthreads; i++) {
336 /*
337 * version 2 of the kexec param format adds the phys cpuid of
338 * booted proc.
339 */
340 if (fdt_version(initial_boot_params) >= 2) {
341 if (be32_to_cpu(intserv[i]) ==
342 fdt_boot_cpuid_phys(initial_boot_params)) {
343 found = boot_cpu_count;
344 found_thread = i;
345 }
346 } else {
347 /*
348 * Check if it's the boot-cpu, set it's hw index now,
349 * unfortunately this format did not support booting
350 * off secondary threads.
351 */
352 if (of_get_flat_dt_prop(node,
353 "linux,boot-cpu", NULL) != NULL)
354 found = boot_cpu_count;
355 }
356 #ifdef CONFIG_SMP
357 /* logical cpu id is always 0 on UP kernels */
358 boot_cpu_count++;
359 #endif
360 }
361
362 /* Not the boot CPU */
363 if (found < 0)
364 return 0;
365 /* to work around p8 subcore mode */
366 nr_cpus_aligned = _ALIGN_UP(nr_cpu_ids, nthreads);
367 if (nr_cpus_aligned != nr_cpu_ids) {
368 pr_info("nr_cpus is forced to align up on threads_per_core,"
369 "from %u to %u\n", nr_cpu_ids, nr_cpus_aligned);
> 370 nr_cpu_ids = nr_cpus_aligned;
371 }
372 DBG("boot cpu: logical %d physical %d\n", found,
373 be32_to_cpu(intserv[found_thread]));
374 boot_cpuid = found;
375
376 /*
377 * PAPR defines "logical" PVR values for cpus that
378 * meet various levels of the architecture:
379 * 0x0f000001 Architecture version 2.04
380 * 0x0f000002 Architecture version 2.05
381 * If the cpu-version property in the cpu node contains
382 * such a value, we call identify_cpu again with the
383 * logical PVR value in order to use the cpu feature
384 * bits appropriate for the architecture level.
385 *
386 * A POWER6 partition in "POWER6 architected" mode
387 * uses the 0x0f000002 PVR value; in POWER5+ mode
388 * it uses 0x0f000001.
389 *
390 * If we're using device tree CPU feature discovery then we don't
391 * support the cpu-version property, and it's the responsibility of the
392 * firmware/hypervisor to provide the correct feature set for the
393 * architecture level via the ibm,powerpc-cpu-features binding.
394 */
395 if (!dt_cpu_ftrs_in_use()) {
396 prop = of_get_flat_dt_prop(node, "cpu-version", NULL);
397 if (prop && (be32_to_cpup(prop) & 0xff000000) == 0x0f000000)
398 identify_cpu(0, be32_to_cpup(prop));
399
400 check_cpu_feature_properties(node);
401 check_cpu_pa_features(node);
402 }
403
404 identical_pvr_fixup(node);
405 init_mmu_slb_size(node);
406
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c index 9dbed48..358adb4 100644 --- a/arch/powerpc/kernel/prom.c +++ b/arch/powerpc/kernel/prom.c @@ -315,6 +315,7 @@ static int __init early_init_dt_scan_cpus(unsigned long node, int len; int found = -1; int found_thread = 0; + unsigned int nr_cpus_aligned; /* We are scanning "cpu" nodes only */ if (type == NULL || strcmp(type, "cpu") != 0) @@ -361,7 +362,13 @@ static int __init early_init_dt_scan_cpus(unsigned long node, /* Not the boot CPU */ if (found < 0) return 0; - + /* to work around p8 subcore mode */ + nr_cpus_aligned = _ALIGN_UP(nr_cpu_ids, nthreads); + if (nr_cpus_aligned != nr_cpu_ids) { + pr_info("nr_cpus is forced to align up on threads_per_core," + "from %u to %u\n", nr_cpu_ids, nr_cpus_aligned); + nr_cpu_ids = nr_cpus_aligned; + } DBG("boot cpu: logical %d physical %d\n", found, be32_to_cpu(intserv[found_thread])); boot_cpuid = found;
With p8 subcore mode, if nr_cpus is not aligned on threads_per_core, then we will hit the following panic: [ 0.310006] Unpacking initramfs... [ 1.105015] Freeing initrd memory: 35968K [ 1.105466] rtas_flash: no firmware flash support [ 1.105688] Unable to handle kernel paging request for data at address 0x00001035 [ 1.105768] Faulting instruction address: 0xc000000000099bb8 [ 1.105837] Oops: Kernel access of bad area, sig: 11 [#1] [ 1.105890] LE SMP NR_CPUS=2048 NUMA PowerNV [ 1.105947] Modules linked in: [ 1.105992] CPU: 8 PID: 11 Comm: migration/8 Not tainted 4.17.0-rc4+ #26 [ 1.106059] NIP: c000000000099bb8 LR: c0000000000ac554 CTR: c000000000099b70 [ 1.106139] REGS: c000000ff649f860 TRAP: 0380 Not tainted (4.17.0-rc4+) [ 1.106205] MSR: 9000000000001033 <SF,HV,ME,IR,DR,RI,LE> CR: 28004022 XER: 00000000 [ 1.106293] CFAR: c0000000000ac550 SOFTE: 3 [ 1.106293] GPR00: c0000000000ac554 c000000ff649fae0 c0000000012e6d00 0000000000000060 [ 1.106293] GPR04: 0000000000000001 c0000000000ac914 9000000000001033 c000003fffffff80 [ 1.106293] GPR08: 0000000000000000 0000000000000001 0000000000000000 9000000000001003 [ 1.106293] GPR12: c000000000099b70 c000000001700000 c000000000141c28 c000000ffa201180 [ 1.106293] GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 1.106293] GPR20: 0000000000000000 0000000000000000 0000000000000001 c000000fffd13840 [ 1.106293] GPR24: c000000fffd13838 0000000000000000 0000000000000001 0000000000000010 [ 1.106293] GPR28: 0000000000000008 0000000000000001 c000000001370548 000000000000000c [ 1.106984] NIP [c000000000099bb8] icp_native_cause_ipi+0x48/0x70 [ 1.107053] LR [c0000000000ac554] pnv_cause_ipi+0x54/0x80 [ 1.107106] Call Trace: [ 1.107137] [c000000ff649fae0] [c0000000000478b4] doorbell_try_core_ipi+0x74/0x90 (unreliable) [ 1.107232] [c000000ff649fb10] [c0000000000ac554] pnv_cause_ipi+0x54/0x80 [ 1.107301] [c000000ff649fb40] [c00000000004ccfc] smp_muxed_ipi_message_pass+0x6c/0x90 [ 1.107384] [c000000ff649fb80] [c0000000000acbe8] cpu_do_split+0x2b8/0x2f0 [ 1.107453] [c000000ff649fbf0] [c0000000000acdb8] cpu_update_split_mode+0x68/0x204 [ 1.107536] [c000000ff649fc40] [c000000000204ab8] multi_cpu_stop+0x1c8/0x200 [ 1.107617] [c000000ff649fca0] [c000000000204eb4] cpu_stopper_thread+0x114/0x1f0 [ 1.107699] [c000000ff649fd60] [c000000000148650] smpboot_thread_fn+0x290/0x2a0 [ 1.107780] [c000000ff649fdc0] [c000000000141d84] kthread+0x164/0x1b0 [ 1.107850] [c000000ff649fe30] [c00000000000b628] ret_from_kernel_thread+0x5c/0xb4 [ 1.107929] Instruction dump: [ 1.107971] 7c7f1b78 60000000 60000000 3d420004 394ab070 7be31f24 39200001 e90a0000 [ 1.108058] 3d42001b 394a2650 7d08182a 7d4a182a <99281035> 39000004 7c0004ac 990a000c [ 1.108150] ---[ end trace 83dad19c162dc306 ]--- [ 1.110137] [ 2.110227] Kernel panic - not syncing: Fatal exception This is caused by that during subcore_init, it IPIs all cpu inside the core, but due to the limitation imposed by nr_cpus, there are no mem allocated for percpu cpu_sibling_map. To avoid a complicated fix, this patch just forces the nr_cpu_ids to be aligned on thread_per_code at the cost of a bit more memory. Signed-off-by: Pingfan Liu <kernelfans@gmail.com> --- arch/powerpc/kernel/prom.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)