From b40d8ed4e42c79f8ed1cf345eed0888f4a2f0678 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Tue, 31 Aug 2010 10:28:17 +0200 Subject: topology/sysfs: Provide book id and siblings attributes Create attributes: /sys/devices/system/cpu/cpuX/topology/book_id /sys/devices/system/cpu/cpuX/topology/book_siblings which show the book id and the book siblings of a cpu. Unlike the attributes for SMT and MC these attributes are only present if CONFIG_SCHED_BOOK is set. There is no reason to pollute sysfs for every architecture with unused attributes. Signed-off-by: Heiko Carstens Signed-off-by: Peter Zijlstra LKML-Reference: <20100831082844.435648457@de.ibm.com> Signed-off-by: Ingo Molnar --- Documentation/cputopology.txt | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-) (limited to 'Documentation') diff --git a/Documentation/cputopology.txt b/Documentation/cputopology.txt index f1c5c4bccd3e..902d3151f527 100644 --- a/Documentation/cputopology.txt +++ b/Documentation/cputopology.txt @@ -14,25 +14,39 @@ to /proc/cpuinfo. identifier (rather than the kernel's). The actual value is architecture and platform dependent. -3) /sys/devices/system/cpu/cpuX/topology/thread_siblings: +3) /sys/devices/system/cpu/cpuX/topology/book_id: + + the book ID of cpuX. Typically it is the hardware platform's + identifier (rather than the kernel's). The actual value is + architecture and platform dependent. + +4) /sys/devices/system/cpu/cpuX/topology/thread_siblings: internel kernel map of cpuX's hardware threads within the same core as cpuX -4) /sys/devices/system/cpu/cpuX/topology/core_siblings: +5) /sys/devices/system/cpu/cpuX/topology/core_siblings: internal kernel map of cpuX's hardware threads within the same physical_package_id. +6) /sys/devices/system/cpu/cpuX/topology/book_siblings: + + internal kernel map of cpuX's hardware threads within the same + book_id. + To implement it in an architecture-neutral way, a new source file, -drivers/base/topology.c, is to export the 4 attributes. +drivers/base/topology.c, is to export the 4 or 6 attributes. The two book +related sysfs files will only be created if CONFIG_SCHED_BOOK is selected. For an architecture to support this feature, it must define some of these macros in include/asm-XXX/topology.h: #define topology_physical_package_id(cpu) #define topology_core_id(cpu) +#define topology_book_id(cpu) #define topology_thread_cpumask(cpu) #define topology_core_cpumask(cpu) +#define topology_book_cpumask(cpu) The type of **_id is int. The type of siblings is (const) struct cpumask *. @@ -45,6 +59,9 @@ not defined by include/asm-XXX/topology.h: 3) thread_siblings: just the given CPU 4) core_siblings: just the given CPU +For architectures that don't support books (CONFIG_SCHED_BOOK) there are no +default definitions for topology_book_id() and topology_book_cpumask(). + Additionally, CPU topology information is provided under /sys/devices/system/cpu and includes these files. The internal source for the output is in brackets ("[]"). -- cgit v1.2.3-58-ga151 From e82b8e4ea4f3dffe6e7939f90e78da675fcc450e Mon Sep 17 00:00:00 2001 From: Venkatesh Pallipadi Date: Mon, 4 Oct 2010 17:03:20 -0700 Subject: x86: Add IRQ_TIME_ACCOUNTING This patch adds IRQ_TIME_ACCOUNTING option on x86 and runtime enables it when TSC is enabled. This change just enables fine grained irq time accounting, isn't used yet. Following patches use it for different purposes. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Peter Zijlstra LKML-Reference: <1286237003-12406-6-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar --- Documentation/kernel-parameters.txt | 4 ++++ arch/x86/Kconfig | 11 +++++++++++ arch/x86/kernel/tsc.c | 8 ++++++++ 3 files changed, 23 insertions(+) (limited to 'Documentation') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 8dd7248508a9..ed05a4a0d242 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2435,6 +2435,10 @@ and is between 256 and 4096 characters. It is defined in the file disables clocksource verification at runtime. Used to enable high-resolution timer mode on older hardware, and in virtualized environment. + [x86] noirqtime: Do not use TSC to do irq accounting. + Used to run time disable IRQ_TIME_ACCOUNTING on any + platforms where RDTSC is slow and this accounting + can add overhead. turbografx.map[2|3]= [HW,JOY] TurboGraFX parallel port interface diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index cea0cd9a316f..f4c70c246ffe 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -795,6 +795,17 @@ config SCHED_MC making when dealing with multi-core CPU chips at a cost of slightly increased overhead in some places. If unsure say N here. +config IRQ_TIME_ACCOUNTING + bool "Fine granularity task level IRQ time accounting" + default n + ---help--- + Select this option to enable fine granularity task irq time + accounting. This is done by reading a timestamp on each + transitions between softirq and hardirq state, so there can be a + small performance impact. + + If in doubt, say N here. + source "kernel/Kconfig.preempt" config X86_UP_APIC diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 26a863a9c2a8..a1c2cd768538 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -104,10 +104,14 @@ int __init notsc_setup(char *str) __setup("notsc", notsc_setup); +static int no_sched_irq_time; + static int __init tsc_setup(char *str) { if (!strcmp(str, "reliable")) tsc_clocksource_reliable = 1; + if (!strncmp(str, "noirqtime", 9)) + no_sched_irq_time = 1; return 1; } @@ -801,6 +805,7 @@ void mark_tsc_unstable(char *reason) if (!tsc_unstable) { tsc_unstable = 1; sched_clock_stable = 0; + disable_sched_clock_irqtime(); printk(KERN_INFO "Marking TSC unstable due to %s\n", reason); /* Change only the rating, when not registered */ if (clocksource_tsc.mult) @@ -987,6 +992,9 @@ void __init tsc_init(void) /* now allow native_sched_clock() to use rdtsc */ tsc_disabled = 0; + if (!no_sched_irq_time) + enable_sched_clock_irqtime(); + lpj = ((u64)tsc_khz * 1000); do_div(lpj, HZ); lpj_fine = lpj; -- cgit v1.2.3-58-ga151