From e4f6937222dbb61b8b8e62caca3d32e648b3b14b Mon Sep 17 00:00:00 2001 From: Venkatesh Pallipadi Date: Mon, 6 Apr 2009 11:26:07 -0700 Subject: ACPI x86: Cleanup acpi_cpufreq structures related to aperf/mperf Change structure name to make the code cleaner and simpler. No functionality change in this patch. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Len Brown --- arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 42 ++++++++++++++---------------- 1 file changed, 20 insertions(+), 22 deletions(-) (limited to 'arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c') diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c index 19f6b9d27e8..340bdbebba0 100644 --- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c +++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c @@ -241,23 +241,23 @@ static u32 get_cur_val(const struct cpumask *mask) return cmd.val; } -struct perf_cur { +struct perf_pair { union { struct { u32 lo; u32 hi; } split; u64 whole; - } aperf_cur, mperf_cur; + } aperf, mperf; }; static long read_measured_perf_ctrs(void *_cur) { - struct perf_cur *cur = _cur; + struct perf_pair *cur = _cur; - rdmsr(MSR_IA32_APERF, cur->aperf_cur.split.lo, cur->aperf_cur.split.hi); - rdmsr(MSR_IA32_MPERF, cur->mperf_cur.split.lo, cur->mperf_cur.split.hi); + rdmsr(MSR_IA32_APERF, cur->aperf.split.lo, cur->aperf.split.hi); + rdmsr(MSR_IA32_MPERF, cur->mperf.split.lo, cur->mperf.split.hi); wrmsr(MSR_IA32_APERF, 0, 0); wrmsr(MSR_IA32_MPERF, 0, 0); @@ -281,7 +281,7 @@ static long read_measured_perf_ctrs(void *_cur) static unsigned int get_measured_perf(struct cpufreq_policy *policy, unsigned int cpu) { - struct perf_cur cur; + struct perf_pair cur; unsigned int perf_percent; unsigned int retval; @@ -294,39 +294,37 @@ static unsigned int get_measured_perf(struct cpufreq_policy *policy, * Get an approximate value. Return failure in case we cannot get * an approximate value. */ - if (unlikely(cur.aperf_cur.split.hi || cur.mperf_cur.split.hi)) { + if (unlikely(cur.aperf.split.hi || cur.mperf.split.hi)) { int shift_count; u32 h; - h = max_t(u32, cur.aperf_cur.split.hi, cur.mperf_cur.split.hi); + h = max_t(u32, cur.aperf.split.hi, cur.mperf.split.hi); shift_count = fls(h); - cur.aperf_cur.whole >>= shift_count; - cur.mperf_cur.whole >>= shift_count; + cur.aperf.whole >>= shift_count; + cur.mperf.whole >>= shift_count; } - if (((unsigned long)(-1) / 100) < cur.aperf_cur.split.lo) { + if (((unsigned long)(-1) / 100) < cur.aperf.split.lo) { int shift_count = 7; - cur.aperf_cur.split.lo >>= shift_count; - cur.mperf_cur.split.lo >>= shift_count; + cur.aperf.split.lo >>= shift_count; + cur.mperf.split.lo >>= shift_count; } - if (cur.aperf_cur.split.lo && cur.mperf_cur.split.lo) - perf_percent = (cur.aperf_cur.split.lo * 100) / - cur.mperf_cur.split.lo; + if (cur.aperf.split.lo && cur.mperf.split.lo) + perf_percent = (cur.aperf.split.lo * 100) / cur.mperf.split.lo; else perf_percent = 0; #else - if (unlikely(((unsigned long)(-1) / 100) < cur.aperf_cur.whole)) { + if (unlikely(((unsigned long)(-1) / 100) < cur.aperf.whole)) { int shift_count = 7; - cur.aperf_cur.whole >>= shift_count; - cur.mperf_cur.whole >>= shift_count; + cur.aperf.whole >>= shift_count; + cur.mperf.whole >>= shift_count; } - if (cur.aperf_cur.whole && cur.mperf_cur.whole) - perf_percent = (cur.aperf_cur.whole * 100) / - cur.mperf_cur.whole; + if (cur.aperf.whole && cur.mperf.whole) + perf_percent = (cur.aperf.whole * 100) / cur.mperf.whole; else perf_percent = 0; -- cgit v1.2.3-70-g09d2 From 18b2646fe3babeb40b34a0c1751e0bf5adfdc64c Mon Sep 17 00:00:00 2001 From: Venkatesh Pallipadi Date: Mon, 6 Apr 2009 11:26:08 -0700 Subject: ACPI x86: Make aperf/mperf MSR access in acpi_cpufreq read_only Do not write zeroes to APERF and MPERF by ondemand governor. With this change, other users can share these MSRs for reads. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Len Brown --- arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) (limited to 'arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c') diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c index 340bdbebba0..9d3af380c6b 100644 --- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c +++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c @@ -68,6 +68,7 @@ struct acpi_cpufreq_data { unsigned int max_freq; unsigned int resume; unsigned int cpu_feature; + u64 saved_aperf, saved_mperf; }; static DEFINE_PER_CPU(struct acpi_cpufreq_data *, drv_data); @@ -259,9 +260,6 @@ static long read_measured_perf_ctrs(void *_cur) rdmsr(MSR_IA32_APERF, cur->aperf.split.lo, cur->aperf.split.hi); rdmsr(MSR_IA32_MPERF, cur->mperf.split.lo, cur->mperf.split.hi); - wrmsr(MSR_IA32_APERF, 0, 0); - wrmsr(MSR_IA32_MPERF, 0, 0); - return 0; } @@ -281,13 +279,20 @@ static long read_measured_perf_ctrs(void *_cur) static unsigned int get_measured_perf(struct cpufreq_policy *policy, unsigned int cpu) { - struct perf_pair cur; + struct perf_pair readin, cur; unsigned int perf_percent; unsigned int retval; - if (!work_on_cpu(cpu, read_measured_perf_ctrs, &cur)) + if (!work_on_cpu(cpu, read_measured_perf_ctrs, &readin)) return 0; + cur.aperf.whole = readin.aperf.whole - + per_cpu(drv_data, cpu)->saved_aperf; + cur.mperf.whole = readin.mperf.whole - + per_cpu(drv_data, cpu)->saved_mperf; + per_cpu(drv_data, cpu)->saved_aperf = readin.aperf.whole; + per_cpu(drv_data, cpu)->saved_mperf = readin.mperf.whole; + #ifdef __i386__ /* * We dont want to do 64 bit divide with 32 bit kernel -- cgit v1.2.3-70-g09d2 From 01599fca6758d2cd133e78f87426fc851c9ea725 Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Mon, 13 Apr 2009 10:27:49 -0700 Subject: cpufreq: use smp_call_function_[single|many]() in acpi-cpufreq.c Atttempting to rid us of the problematic work_on_cpu(). Just use smp_call_fuction_single() here. This repairs a 10% sysbench(oltp)+mysql regression which Mike reported, due to commit 6b44003e5ca66a3fffeb5bc90f40ada2c4340896 Author: Andrew Morton Date: Thu Apr 9 09:50:37 2009 -0600 work_on_cpu(): rewrite it to create a kernel thread on demand It seems that the kernel calls these acpi-cpufreq functions at a quite high frequency. Valdis Kletnieks also reports that this causes 70-90 forks per second on his hardware. Cc: Valdis.Kletnieks@vt.edu Cc: Rusty Russell Cc: Venkatesh Pallipadi Cc: Len Brown Cc: Zhao Yakui Acked-by: Dave Jones Cc: Thomas Gleixner Tested-by: Mike Galbraith Cc: "Zhang, Yanmin" Signed-off-by: Andrew Morton Acked-by: Ingo Molnar [ Made it use smp_call_function_many() instead of looping over cpu's with smp_call_function_single() - Linus ] Signed-off-by: Linus Torvalds --- arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 24 +++++++++--------------- 1 file changed, 9 insertions(+), 15 deletions(-) (limited to 'arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c') diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c index 9d3af380c6b..3e3cd3db7a0 100644 --- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c +++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c @@ -153,7 +153,8 @@ struct drv_cmd { u32 val; }; -static long do_drv_read(void *_cmd) +/* Called via smp_call_function_single(), on the target CPU */ +static void do_drv_read(void *_cmd) { struct drv_cmd *cmd = _cmd; u32 h; @@ -170,10 +171,10 @@ static long do_drv_read(void *_cmd) default: break; } - return 0; } -static long do_drv_write(void *_cmd) +/* Called via smp_call_function_many(), on the target CPUs */ +static void do_drv_write(void *_cmd) { struct drv_cmd *cmd = _cmd; u32 lo, hi; @@ -192,23 +193,18 @@ static long do_drv_write(void *_cmd) default: break; } - return 0; } static void drv_read(struct drv_cmd *cmd) { cmd->val = 0; - work_on_cpu(cpumask_any(cmd->mask), do_drv_read, cmd); + smp_call_function_single(cpumask_any(cmd->mask), do_drv_read, cmd, 1); } static void drv_write(struct drv_cmd *cmd) { - unsigned int i; - - for_each_cpu(i, cmd->mask) { - work_on_cpu(i, do_drv_write, cmd); - } + smp_call_function_many(cmd->mask, do_drv_write, cmd, 1); } static u32 get_cur_val(const struct cpumask *mask) @@ -252,15 +248,13 @@ struct perf_pair { } aperf, mperf; }; - -static long read_measured_perf_ctrs(void *_cur) +/* Called via smp_call_function_single(), on the target CPU */ +static void read_measured_perf_ctrs(void *_cur) { struct perf_pair *cur = _cur; rdmsr(MSR_IA32_APERF, cur->aperf.split.lo, cur->aperf.split.hi); rdmsr(MSR_IA32_MPERF, cur->mperf.split.lo, cur->mperf.split.hi); - - return 0; } /* @@ -283,7 +277,7 @@ static unsigned int get_measured_perf(struct cpufreq_policy *policy, unsigned int perf_percent; unsigned int retval; - if (!work_on_cpu(cpu, read_measured_perf_ctrs, &readin)) + if (smp_call_function_single(cpu, read_measured_perf_ctrs, &cur, 1)) return 0; cur.aperf.whole = readin.aperf.whole - -- cgit v1.2.3-70-g09d2 From 1c98aa7424ff163637d8321674ec58dee28152d4 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Mon, 13 Apr 2009 18:09:20 -0700 Subject: Fix quilt merge error in acpi-cpufreq.c We ended up incorrectly using '&cur' instead of '&readin' in the work_on_cpu() -> smp_call_function_single() transformation in commit 01599fca6758d2cd133e78f87426fc851c9ea725 ("cpufreq: use smp_call_function_[single|many]() in acpi-cpufreq.c"). Andrew explains: "OK, the acpi tree went and had conflicting changes merged into it after I'd written the patch and it appears that I incorrectly reverted part of 18b2646fe3babeb40b34a0c1751e0bf5adfdc64c while fixing the resulting rejects. Switching it to `readin' looks correct." Acked-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c') diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c index 3e3cd3db7a0..837c2c4cc20 100644 --- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c +++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c @@ -277,7 +277,7 @@ static unsigned int get_measured_perf(struct cpufreq_policy *policy, unsigned int perf_percent; unsigned int retval; - if (smp_call_function_single(cpu, read_measured_perf_ctrs, &cur, 1)) + if (smp_call_function_single(cpu, read_measured_perf_ctrs, &readin, 1)) return 0; cur.aperf.whole = readin.aperf.whole - -- cgit v1.2.3-70-g09d2 From ea34f43a074af85823e49b9bf62f47d8d3f0e81a Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Wed, 15 Apr 2009 08:05:13 -0700 Subject: acpi-cpufreq: fix 'smp_call_function_many()' confusion It turns out that 'smp_call_function_many()' doesn't work at all like 'smp_call_function_single()', and my change to Andrew's patch to use it rather than a loop over all CPU's acpi-cpufreq doesn't work. My bad. 'smp_call_function_many()' has two "features" (aka "documented bugs"): (a) it needs to be called with preemption disabled, because it uses smp_processor_id() without guarding the CPU lookup with 'get_cpu()' and 'put_cpu()' like the 'single' variant does. (b) even if the current CPU is part of the CPU mask, it won't do the call on that CPU. Still, we're better off trying to use 'smp_call_function_many()' than looping over CPU's, since it at least in theory allows us to use a broadcast IPI and do it all in parallel. So let's just work around the silly semantic bugs in that function. Reported-and-tested-by: Ali Gholami Rudi Cc: Ingo Molnar Cc: Andrew Morton , Cc: Rusty Russell Cc: Dave Jones Signed-off-by: Linus Torvalds --- arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c') diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c index 837c2c4cc20..ecdb682ab51 100644 --- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c +++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c @@ -204,7 +204,13 @@ static void drv_read(struct drv_cmd *cmd) static void drv_write(struct drv_cmd *cmd) { + int this_cpu; + + this_cpu = get_cpu(); + if (cpumask_test_cpu(this_cpu, cmd->mask)) + do_drv_write(cmd); smp_call_function_many(cmd->mask, do_drv_write, cmd, 1); + put_cpu(); } static u32 get_cur_val(const struct cpumask *mask) -- cgit v1.2.3-70-g09d2 From 093f13e23137b9e5f7629dd5932ceea1419e2b61 Mon Sep 17 00:00:00 2001 From: "Pallipadi, Venkatesh" Date: Wed, 15 Apr 2009 10:37:33 -0700 Subject: x86, acpi_cpufreq: Fix the NULL pointer dereference in get_measured_perf Fix for a regression that was introduced by earlier commit 18b2646fe3babeb40b34a0c1751e0bf5adfdc64c on Mon Apr 6 11:26:08 2009 Regression resulted in the below error happened on systems with software coordination where per_cpu acpi data will not be initiated for secondary CPUs in a P-state domain. On Tue, 2009-04-14 at 23:01 -0700, Zhang, Yanmin wrote: My machine hanged with kernel 2.6.30-rc2 when script read > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor. > > opps happens in get_measured_perf: > > cur.aperf.whole = readin.aperf.whole - > per_cpu(drv_data, cpu)->saved_aperf; > > Because per_cpu(drv_data, cpu)=NULL. > > So function get_measured_perf should check if (per_cpu(drv_data, > cpu)==NULL) > and return 0 if it's NULL. --------------sys log------------------ BUG: unable to handle kernel NULL pointer dereference at 0000000000000020 IP: [] get_measured_perf+0x4a/0xf9 PGD a7dd88067 PUD a7ccf5067 PMD 0 Oops: 0000 [#1] SMP last sysfs file: /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor CPU 0 Modules linked in: video output Pid: 2091, comm: kondemand/0 Not tainted 2.6.30-rc2 #1 MP Server RIP: 0010:[] [] get_measured_perf+0x4a/0xf9 RSP: 0018:ffff880a7d56de20 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 00000046241a42b6 RCX: ffff88004d219000 RDX: 000000000000b660 RSI: 0000000000000020 RDI: 0000000000000001 RBP: ffff880a7f052000 R08: 00000046241a42b6 R09: ffffffff807639f0 R10: 00000000ffffffea R11: ffffffff802207f4 R12: ffff880a7f052000 R13: ffff88004d20e460 R14: 0000000000ddd5a6 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff88004d200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b CR2: 0000000000000020 CR3: 0000000a7f1bf000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process kondemand/0 (pid: 2091, threadinfo ffff880a7d56c000, task ffff880a7d4d18c0) Stack: ffff880a7f052078 ffffffff803efd54 00000046241a42b6 000000462ffa9e95 0000000000000001 0000000000000001 00000000ffffffea ffffffff8064f41a 0000000000000012 0000000000000012 ffff880a7f052000 ffffffff80650547 Call Trace: [] ? kobject_get+0x12/0x17 [] ? __cpufreq_driver_getavg+0x42/0x57 [] ? do_dbs_timer+0x147/0x272 [] ? do_dbs_timer+0x0/0x272 [] ? worker_thread+0x15b/0x1f5 [] ? autoremove_wake_function+0x0/0x2e [] ? worker_thread+0x0/0x1f5 [] ? kthread+0x54/0x83 [] ? child_rip+0xa/0x20 [] ? kthread+0x0/0x83 [] ? child_rip+0x0/0x20 Code: 99 a6 03 00 31 c9 85 c0 0f 85 c3 00 00 00 89 df 4c 8b 44 24 10 48 c7 c2 60 b6 00 00 48 8b 0c fd e0 30 a5 80 4c 89 c3 48 8b 04 0a <48> 2b 58 20 48 8b 44 24 18 48 89 1c 24 48 8b 34 0a 48 2b 46 28 RIP [] get_measured_perf+0x4a/0xf9 RSP CR2: 0000000000000020 ---[ end trace 2b8fac9a49e19ad4 ]--- Tested-by: "Zhang, Yanmin" Signed-off-by: Venkatesh Pallipadi Signed-off-by: Len Brown --- arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) (limited to 'arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c') diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c index ecdb682ab51..dd0bd76d14c 100644 --- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c +++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c @@ -68,11 +68,16 @@ struct acpi_cpufreq_data { unsigned int max_freq; unsigned int resume; unsigned int cpu_feature; - u64 saved_aperf, saved_mperf; }; static DEFINE_PER_CPU(struct acpi_cpufreq_data *, drv_data); +struct acpi_msr_data { + u64 saved_aperf, saved_mperf; +}; + +static DEFINE_PER_CPU(struct acpi_msr_data, msr_data); + DEFINE_TRACE(power_mark); /* acpi_perf_data is a pointer to percpu data. */ @@ -287,11 +292,11 @@ static unsigned int get_measured_perf(struct cpufreq_policy *policy, return 0; cur.aperf.whole = readin.aperf.whole - - per_cpu(drv_data, cpu)->saved_aperf; + per_cpu(msr_data, cpu).saved_aperf; cur.mperf.whole = readin.mperf.whole - - per_cpu(drv_data, cpu)->saved_mperf; - per_cpu(drv_data, cpu)->saved_aperf = readin.aperf.whole; - per_cpu(drv_data, cpu)->saved_mperf = readin.mperf.whole; + per_cpu(msr_data, cpu).saved_mperf; + per_cpu(msr_data, cpu).saved_aperf = readin.aperf.whole; + per_cpu(msr_data, cpu).saved_mperf = readin.mperf.whole; #ifdef __i386__ /* -- cgit v1.2.3-70-g09d2 From e0e8c4e512e92bc25c19bd8d4926de17d2f8fbf2 Mon Sep 17 00:00:00 2001 From: Thomas Renninger Date: Fri, 17 Apr 2009 16:22:06 +0200 Subject: acpi-cpufreq: Cleanup: Use printk_once Signed-off-by: Thomas Renninger Signed-off-by: Len Brown --- arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) (limited to 'arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c') diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c index dd0bd76d14c..4eab747a896 100644 --- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c +++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c @@ -693,13 +693,9 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy) /* Check for high latency (>20uS) from buggy BIOSes, like on T42 */ if (perf->control_register.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE && policy->cpuinfo.transition_latency > 20 * 1000) { - static int print_once; policy->cpuinfo.transition_latency = 20 * 1000; - if (!print_once) { - print_once = 1; - printk(KERN_INFO "Capping off P-state tranision latency" - " at 20 uS\n"); - } + printk_once(KERN_INFO "Capping off P-state tranision" + " latency at 20 uS\n"); } data->max_freq = perf->states[0].core_frequency * 1000; -- cgit v1.2.3-70-g09d2 From d91758f5ddb80e91176fa2cf80c88c1633950b3d Mon Sep 17 00:00:00 2001 From: Thomas Renninger Date: Fri, 17 Apr 2009 16:22:07 +0200 Subject: acpi-cpufreq: style-only: add parens to math expression Signed-off-by: Thomas Renninger Signed-off-by: Len Brown --- arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c') diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c index 4eab747a896..aec3161abed 100644 --- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c +++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c @@ -340,7 +340,7 @@ static unsigned int get_measured_perf(struct cpufreq_policy *policy, #endif - retval = per_cpu(drv_data, policy->cpu)->max_freq * perf_percent / 100; + retval = (per_cpu(drv_data, policy->cpu)->max_freq * perf_percent) / 100; return retval; } -- cgit v1.2.3-70-g09d2 From d876dfbbf5c8728102fb4f683450fa9ae3259cda Mon Sep 17 00:00:00 2001 From: Thomas Renninger Date: Fri, 17 Apr 2009 16:22:08 +0200 Subject: acpi-cpufreq: Do not let get_measured perf depend on internal variable Take already available policy->cpuinfo.max_freq and get rid of acpi-cpufreq specific max_freq variable. This implies that P0 is always the highest frequency which should always be true as ACPI spec says: As a result, the zeroth entry describes the highest performance state Signed-off-by: Thomas Renninger Acked-by: Venkatesh Pallipadi Signed-off-by: Len Brown --- arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c') diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c index aec3161abed..208ecf6643d 100644 --- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c +++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c @@ -65,7 +65,6 @@ enum { struct acpi_cpufreq_data { struct acpi_processor_performance *acpi_data; struct cpufreq_frequency_table *freq_table; - unsigned int max_freq; unsigned int resume; unsigned int cpu_feature; }; @@ -340,7 +339,7 @@ static unsigned int get_measured_perf(struct cpufreq_policy *policy, #endif - retval = (per_cpu(drv_data, policy->cpu)->max_freq * perf_percent) / 100; + retval = (policy->cpuinfo.max_freq * perf_percent) / 100; return retval; } @@ -698,7 +697,6 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy) " latency at 20 uS\n"); } - data->max_freq = perf->states[0].core_frequency * 1000; /* table init */ for (i = 0; i < perf->state_count; i++) { if (i > 0 && perf->states[i].core_frequency >= @@ -717,6 +715,9 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy) if (result) goto err_freqfree; + if (perf->states[0].core_frequency * 1000 != policy->cpuinfo.max_freq) + printk(KERN_WARNING FW_WARN "P-state 0 is not max freq\n"); + switch (perf->control_register.space_id) { case ACPI_ADR_SPACE_SYSTEM_IO: /* Current speed is unknown and not detectable by IO port */ -- cgit v1.2.3-70-g09d2