/* -*- linux-c -*- ------------------------------------------------------- * * * Copyright 2002 H. Peter Anvin - All Rights Reserved * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, Inc., 53 Temple Place Ste 330, * Boston MA 02111-1307, USA; either version 2 of the License, or * (at your option) any later version; incorporated herein by reference. * * ----------------------------------------------------------------------- */ /* * raid6/algos.c * * Algorithm list and algorithm selection for RAID-6 */ #include #ifndef __KERNEL__ #include #include #else #include #include #if !RAID6_USE_EMPTY_ZERO_PAGE /* In .bss so it's zeroed */ const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256))); EXPORT_SYMBOL(raid6_empty_zero_page); #endif #endif struct raid6_calls raid6_call; EXPORT_SYMBOL_GPL(raid6_call); const struct raid6_calls * const raid6_algos[] = { #if defined(__ia64__) &raid6_intx16, &raid6_intx32, #endif #if defined(__i386__) && !defined(__arch_um__) &raid6_mmxx1, &raid6_mmxx2, &raid6_sse1x1, &raid6_sse1x2, &raid6_sse2x1, &raid6_sse2x2, #ifdef CONFIG_AS_AVX2 &raid6_avx2x1, &raid6_avx2x2, #endif #ifdef CONFIG_AS_AVX512 &raid6_avx512x1, &raid6_avx512x2, #endif #endif #if defined(__x86_64__) && !defined(__arch_um__) &raid6_sse2x1, &raid6_sse2x2, &raid6_sse2x4, #ifdef CONFIG_AS_AVX2 &raid6_avx2x1, &raid6_avx2x2, &raid6_avx2x4, #endif #ifdef CONFIG_AS_AVX512 &raid6_avx512x1, &raid6_avx512x2, &raid6_avx512x4, #endif #endif #ifdef CONFIG_ALTIVEC &raid6_altivec1, &raid6_altivec2, &raid6_altivec4, &raid6_altivec8, #endif #if defined(CONFIG_TILEGX) &raid6_tilegx8, #endif #if defined(CONFIG_S390) &raid6_s390vx8, #endif &raid6_intx1, &raid6_intx2, &raid6_intx4, &raid6_intx8, #ifdef CONFIG_KERNEL_MODE_NEON &raid6_neonx1, &raid6_neonx2, &raid6_neonx4, &raid6_neonx8, #endif NULL }; void (*raid6_2data_recov)(int, size_t, int, int, void **); EXPORT_SYMBOL_GPL(raid6_2data_recov); void (*raid6_datap_recov)(int, size_t, int, void **); EXPORT_SYMBOL_GPL(raid6_datap_recov); const struct raid6_recov_calls *const raid6_recov_algos[] = { #ifdef CONFIG_AS_AVX512 &raid6_recov_avx512, #endif #ifdef CONFIG_AS_AVX2 &raid6_recov_avx2, #endif #ifdef CONFIG_AS_SSSE3 &raid6_recov_ssse3, #endif #ifdef CONFIG_S390 &raid6_recov_s390xc, #endif &raid6_recov_intx1, NULL }; #ifdef __KERNEL__ #define RAID6_TIME_JIFFIES_LG2 4 #else /* Need more time to be stable in userspace */ #define RAID6_TIME_JIFFIES_LG2 9 #define time_before(x, y) ((x) < (y)) #endif static inline const struct raid6_recov_calls *raid6_choose_recov(void) { const struct raid6_recov_calls *const *algo; const struct raid6_recov_calls *best; for (best = NULL, algo = raid6_recov_algos; *algo; algo++) if (!best || (*algo)->priority > best->priority) if (!(*algo)->valid || (*algo)->valid()) best = *algo; if (best) { raid6_2data_recov = best->data2; raid6_datap_recov = best->datap; pr_info("raid6: using %s recovery algorithm\n", best->name); } else pr_err("raid6: Yikes! No recovery algorithm found!\n"); return best; } static inline const struct raid6_calls *raid6_choose_gen( void *(*const dptrs)[(65536/PAGE_SIZE)+2], const int disks) { unsigned long perf, bestgenperf, bestxorperf, j0, j1; int start = (disks>>1)-1, stop = disks-3; /* work on the second half of the disks */ const struct raid6_calls *const *algo; const struct raid6_calls *best; for (bestgenperf = 0, bestxorperf = 0, best = NULL, algo = raid6_algos; *algo; algo++) { if (!best || (*algo)->prefer >= best->prefer) { if ((*algo)->valid && !(*algo)->valid()) continue; perf = 0; preempt_disable(); j0 = jiffies; while ((j1 = jiffies) == j0) cpu_relax(); while (time_before(jiffies, j1 + (1<gen_syndrome(disks, PAGE_SIZE, *dptrs); perf++; } preempt_enable(); if (perf > bestgenperf) { bestgenperf = perf; best = *algo; } pr_info("raid6: %-8s gen() %5ld MB/s\n", (*algo)->name, (perf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2)); if (!(*algo)->xor_syndrome) continue; perf = 0; preempt_disable(); j0 = jiffies; while ((j1 = jiffies) == j0) cpu_relax(); while (time_before(jiffies, j1 + (1<xor_syndrome(disks, start, stop, PAGE_SIZE, *dptrs); perf++; } preempt_enable(); if (best == *algo) bestxorperf = perf; pr_info("raid6: %-8s xor() %5ld MB/s\n", (*algo)->name, (perf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2+1)); } } if (best) { pr_info("raid6: using algorithm %s gen() %ld MB/s\n", best->name, (bestgenperf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2)); if (best->xor_syndrome) pr_info("raid6: .... xor() %ld MB/s, rmw enabled\n", (bestxorperf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2+1)); raid6_call = *best; } else pr_err("raid6: Yikes! No algorithm found!\n"); return best; } /* Try to pick the best algorithm */ /* This code uses the gfmul table as convenient data set to abuse */ int __init raid6_select_algo(void) { const int disks = (65536/PAGE_SIZE)+2; const struct raid6_calls *gen_best; const struct raid6_recov_calls *rec_best; char *syndromes; void *dptrs[(65536/PAGE_SIZE)+2]; int i; for (i = 0; i < disks-2; i++) dptrs[i] = ((char *)raid6_gfmul) + PAGE_SIZE*i; /* Normal code - use a 2-page allocation to avoid D$ conflict */ syndromes = (void *) __get_free_pages(GFP_KERNEL, 1); if (!syndromes) { pr_err("raid6: Yikes! No memory available.\n"); return -ENOMEM; } dptrs[disks-2] = syndromes; dptrs[disks-1] = syndromes + PAGE_SIZE; /* select raid gen_syndrome function */ gen_best = raid6_choose_gen(&dptrs, disks); /* select raid recover functions */ rec_best = raid6_choose_recov(); free_pages((unsigned long)syndromes, 1); return gen_best && rec_best ? 0 : -EINVAL; } static void raid6_exit(void) { do { } while (0); } subsys_initcall(raid6_select_algo); module_exit(raid6_exit); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("RAID6 Q-syndrome calculations"); gy efficiency optimization
Some Kabylake desktop processors may not reach max turbo when running in HWP mode, even if running under sustained 100% utilization. This occurs when the HWP.EPP (Energy Performance Preference) is set to "balance_power" (0x80) -- the default on most systems. It occurs because the platform BIOS may erroneously enable an energy-efficiency setting -- MSR_IA32_POWER_CTL BIT-EE, which is not recommended to be enabled on this SKU. On the failing systems, this BIOS issue was not discovered when the desktop motherboard was tested with Windows, because the BIOS also neglects to provide the ACPI/CPPC table, that Windows requires to enable HWP, and so Windows runs in legacy P-state mode, where this setting has no effect. Linux' intel_pstate driver does not require ACPI/CPPC to enable HWP, and so it runs in HWP mode, exposing this incorrect BIOS configuration. There are several ways to address this problem. First, Linux can also run in legacy P-state mode on this system. As intel_pstate is how Linux enables HWP, booting with "intel_pstate=disable" will run in acpi-cpufreq/ondemand legacy p-state mode. Or second, the "performance" governor can be used with intel_pstate, which will modify HWP.EPP to 0. Or third, starting in 4.10, the /sys/devices/system/cpu/cpufreq/policy*/energy_performance_preference attribute in can be updated from "balance_power" to "performance". Or fourth, apply this patch, which fixes the erroneous setting of MSR_IA32_POWER_CTL BIT_EE on this model, allowing the default configuration to function as designed. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Reviewed-by: Len Brown <len.brown@intel.com> Cc: 4.6+ <stable@vger.kernel.org> # 4.6+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'net/can/proc.c')