diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-event_source-devices-events | 62 | ||||
| -rw-r--r-- | Documentation/ABI/testing/sysfs-platform-ts5500 | 47 | ||||
| -rw-r--r-- | Documentation/PCI/MSI-HOWTO.txt | 37 | ||||
| -rw-r--r-- | Documentation/atomic_ops.txt | 2 | ||||
| -rw-r--r-- | Documentation/cgroups/00-INDEX | 2 | ||||
| -rw-r--r-- | Documentation/cgroups/cgroup_event_listener.c | 110 | ||||
| -rw-r--r-- | Documentation/cgroups/memcg_test.txt | 3 | ||||
| -rw-r--r-- | Documentation/memory-barriers.txt | 1 | ||||
| -rw-r--r-- | Documentation/trace/ftrace.txt | 83 |
9 files changed, 228 insertions, 119 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-event_source-devices-events b/Documentation/ABI/testing/sysfs-bus-event_source-devices-events new file mode 100644 index 00000000000..0adeb524c0d --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-event_source-devices-events @@ -0,0 +1,62 @@ +What: /sys/devices/cpu/events/ + /sys/devices/cpu/events/branch-misses + /sys/devices/cpu/events/cache-references + /sys/devices/cpu/events/cache-misses + /sys/devices/cpu/events/stalled-cycles-frontend + /sys/devices/cpu/events/branch-instructions + /sys/devices/cpu/events/stalled-cycles-backend + /sys/devices/cpu/events/instructions + /sys/devices/cpu/events/cpu-cycles + +Date: 2013/01/08 + +Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> + +Description: Generic performance monitoring events + + A collection of performance monitoring events that may be + supported by many/most CPUs. These events can be monitored + using the 'perf(1)' tool. + + The contents of each file would look like: + + event=0xNNNN + + where 'N' is a hex digit and the number '0xNNNN' shows the + "raw code" for the perf event identified by the file's + "basename". + + +What: /sys/devices/cpu/events/PM_LD_MISS_L1 + /sys/devices/cpu/events/PM_LD_REF_L1 + /sys/devices/cpu/events/PM_CYC + /sys/devices/cpu/events/PM_BRU_FIN + /sys/devices/cpu/events/PM_GCT_NOSLOT_CYC + /sys/devices/cpu/events/PM_BRU_MPRED + /sys/devices/cpu/events/PM_INST_CMPL + /sys/devices/cpu/events/PM_CMPLU_STALL + +Date: 2013/01/08 + +Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> + Linux Powerpc mailing list <linuxppc-dev@ozlabs.org> + +Description: POWER-systems specific performance monitoring events + + A collection of performance monitoring events that may be + supported by the POWER CPU. These events can be monitored + using the 'perf(1)' tool. + + These events may not be supported by other CPUs. + + The contents of each file would look like: + + event=0xNNNN + + where 'N' is a hex digit and the number '0xNNNN' shows the + "raw code" for the perf event identified by the file's + "basename". + + Further, multiple terms like 'event=0xNNNN' can be specified + and separated with comma. All available terms are defined in + the /sys/bus/event_source/devices/<dev>/format file. diff --git a/Documentation/ABI/testing/sysfs-platform-ts5500 b/Documentation/ABI/testing/sysfs-platform-ts5500 new file mode 100644 index 00000000000..c88375a537a --- /dev/null +++ b/Documentation/ABI/testing/sysfs-platform-ts5500 @@ -0,0 +1,47 @@ +What: /sys/devices/platform/ts5500/adc +Date: January 2013 +KernelVersion: 3.7 +Contact: "Savoir-faire Linux Inc." <kernel@savoirfairelinux.com> +Description: + Indicates the presence of an A/D Converter. If it is present, + it will display "1", otherwise "0". + +What: /sys/devices/platform/ts5500/ereset +Date: January 2013 +KernelVersion: 3.7 +Contact: "Savoir-faire Linux Inc." <kernel@savoirfairelinux.com> +Description: + Indicates the presence of an external reset. If it is present, + it will display "1", otherwise "0". + +What: /sys/devices/platform/ts5500/id +Date: January 2013 +KernelVersion: 3.7 +Contact: "Savoir-faire Linux Inc." <kernel@savoirfairelinux.com> +Description: + Product ID of the TS board. TS-5500 ID is 0x60. + +What: /sys/devices/platform/ts5500/jumpers +Date: January 2013 +KernelVersion: 3.7 +Contact: "Savoir-faire Linux Inc." <kernel@savoirfairelinux.com> +Description: + Bitfield showing the jumpers' state. If a jumper is present, + the corresponding bit is set. For instance, 0x0e means jumpers + 2, 3 and 4 are set. + +What: /sys/devices/platform/ts5500/rs485 +Date: January 2013 +KernelVersion: 3.7 +Contact: "Savoir-faire Linux Inc." <kernel@savoirfairelinux.com> +Description: + Indicates the presence of the RS485 option. If it is present, + it will display "1", otherwise "0". + +What: /sys/devices/platform/ts5500/sram +Date: January 2013 +KernelVersion: 3.7 +Contact: "Savoir-faire Linux Inc." <kernel@savoirfairelinux.com> +Description: + Indicates the presence of the SRAM option. If it is present, + it will display "1", otherwise "0". diff --git a/Documentation/PCI/MSI-HOWTO.txt b/Documentation/PCI/MSI-HOWTO.txt index 53e6fca146d..a09178086c3 100644 --- a/Documentation/PCI/MSI-HOWTO.txt +++ b/Documentation/PCI/MSI-HOWTO.txt @@ -127,15 +127,42 @@ on the number of vectors that can be allocated; pci_enable_msi_block() returns as soon as it finds any constraint that doesn't allow the call to succeed. -4.2.3 pci_disable_msi +4.2.3 pci_enable_msi_block_auto + +int pci_enable_msi_block_auto(struct pci_dev *dev, unsigned int *count) + +This variation on pci_enable_msi() call allows a device driver to request +the maximum possible number of MSIs. The MSI specification only allows +interrupts to be allocated in powers of two, up to a maximum of 2^5 (32). + +If this function returns a positive number, it indicates that it has +succeeded and the returned value is the number of allocated interrupts. In +this case, the function enables MSI on this device and updates dev->irq to +be the lowest of the new interrupts assigned to it. The other interrupts +assigned to the device are in the range dev->irq to dev->irq + returned +value - 1. + +If this function returns a negative number, it indicates an error and +the driver should not attempt to request any more MSI interrupts for +this device. + +If the device driver needs to know the number of interrupts the device +supports it can pass the pointer count where that number is stored. The +device driver must decide what action to take if pci_enable_msi_block_auto() +succeeds, but returns a value less than the number of interrupts supported. +If the device driver does not need to know the number of interrupts +supported, it can set the pointer count to NULL. + +4.2.4 pci_disable_msi void pci_disable_msi(struct pci_dev *dev) This function should be used to undo the effect of pci_enable_msi() or -pci_enable_msi_block(). Calling it restores dev->irq to the pin-based -interrupt number and frees the previously allocated message signaled -interrupt(s). The interrupt may subsequently be assigned to another -device, so drivers should not cache the value of dev->irq. +pci_enable_msi_block() or pci_enable_msi_block_auto(). Calling it restores +dev->irq to the pin-based interrupt number and frees the previously +allocated message signaled interrupt(s). The interrupt may subsequently be +assigned to another device, so drivers should not cache the value of +dev->irq. Before calling this function, a device driver must always call free_irq() on any interrupt for which it previously called request_irq(). diff --git a/Documentation/atomic_ops.txt b/Documentation/atomic_ops.txt index 27f2b21a9d5..d9ca5be9b47 100644 --- a/Documentation/atomic_ops.txt +++ b/Documentation/atomic_ops.txt @@ -253,6 +253,8 @@ This performs an atomic exchange operation on the atomic variable v, setting the given new value. It returns the old value that the atomic variable v had just before the operation. +atomic_xchg requires explicit memory barriers around the operation. + int atomic_cmpxchg(atomic_t *v, int old, int new); This performs an atomic compare exchange operation on the atomic value v, diff --git a/Documentation/cgroups/00-INDEX b/Documentation/cgroups/00-INDEX index f78b90a35ad..f5635a09c3f 100644 --- a/Documentation/cgroups/00-INDEX +++ b/Documentation/cgroups/00-INDEX @@ -4,8 +4,6 @@ blkio-controller.txt - Description for Block IO Controller, implementation and usage details. cgroups.txt - Control Groups definition, implementation details, examples and API. -cgroup_event_listener.c - - A user program for cgroup listener. cpuacct.txt - CPU Accounting Controller; account CPU usage for groups of tasks. cpusets.txt diff --git a/Documentation/cgroups/cgroup_event_listener.c b/Documentation/cgroups/cgroup_event_listener.c deleted file mode 100644 index 3e082f96dc1..00000000000 --- a/Documentation/cgroups/cgroup_event_listener.c +++ /dev/null @@ -1,110 +0,0 @@ -/* - * cgroup_event_listener.c - Simple listener of cgroup events - * - * Copyright (C) Kirill A. Shutemov <kirill@shutemov.name> - */ - -#include <assert.h> -#include <errno.h> -#include <fcntl.h> -#include <libgen.h> -#include <limits.h> -#include <stdio.h> -#include <string.h> -#include <unistd.h> - -#include <sys/eventfd.h> - -#define USAGE_STR "Usage: cgroup_event_listener <path-to-control-file> <args>\n" - -int main(int argc, char **argv) -{ - int efd = -1; - int cfd = -1; - int event_control = -1; - char event_control_path[PATH_MAX]; - char line[LINE_MAX]; - int ret; - - if (argc != 3) { - fputs(USAGE_STR, stderr); - return 1; - } - - cfd = open(argv[1], O_RDONLY); - if (cfd == -1) { - fprintf(stderr, "Cannot open %s: %s\n", argv[1], - strerror(errno)); - goto out; - } - - ret = snprintf(event_control_path, PATH_MAX, "%s/cgroup.event_control", - dirname(argv[1])); - if (ret >= PATH_MAX) { - fputs("Path to cgroup.event_control is too long\n", stderr); - goto out; - } - - event_control = open(event_control_path, O_WRONLY); - if (event_control == -1) { - fprintf(stderr, "Cannot open %s: %s\n", event_control_path, - strerror(errno)); - goto out; - } - - efd = eventfd(0, 0); - if (efd == -1) { - perror("eventfd() failed"); - goto out; - } - - ret = snprintf(line, LINE_MAX, "%d %d %s", efd, cfd, argv[2]); - if (ret >= LINE_MAX) { - fputs("Arguments string is too long\n", stderr); - goto out; - } - - ret = write(event_control, line, strlen(line) + 1); - if (ret == -1) { - perror("Cannot write to cgroup.event_control"); - goto out; - } - - while (1) { - uint64_t result; - - ret = read(efd, &result, sizeof(result)); - if (ret == -1) { - if (errno == EINTR) - continue; - perror("Cannot read from eventfd"); - break; - } - assert(ret == sizeof(result)); - - ret = access(event_control_path, W_OK); - if ((ret == -1) && (errno == ENOENT)) { - puts("The cgroup seems to have removed."); - ret = 0; - break; - } - - if (ret == -1) { - perror("cgroup.event_control " - "is not accessible any more"); - break; - } - - printf("%s %s: crossed\n", argv[1], argv[2]); - } - -out: - if (efd >= 0) - close(efd); - if (event_control >= 0) - close(event_control); - if (cfd >= 0) - close(cfd); - - return (ret != 0); -} diff --git a/Documentation/cgroups/memcg_test.txt b/Documentation/cgroups/memcg_test.txt index fc8fa97a09a..ce94a83a7d9 100644 --- a/Documentation/cgroups/memcg_test.txt +++ b/Documentation/cgroups/memcg_test.txt @@ -399,8 +399,7 @@ Under below explanation, we assume CONFIG_MEM_RES_CTRL_SWAP=y. 9.10 Memory thresholds Memory controller implements memory thresholds using cgroups notification - API. You can use Documentation/cgroups/cgroup_event_listener.c to test - it. + API. You can use tools/cgroup/cgroup_event_listener.c to test it. (Shell-A) Create cgroup and run event listener # mkdir /cgroup/A diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt index 3c4e1b3b80a..fa5d8a9ae20 100644 --- a/Documentation/memory-barriers.txt +++ b/Documentation/memory-barriers.txt @@ -1685,6 +1685,7 @@ explicit lock operations, described later). These include: xchg(); cmpxchg(); + atomic_xchg(); atomic_cmpxchg(); atomic_inc_return(); atomic_dec_return(); diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt index 6f51fed45f2..53d6a3c51d8 100644 --- a/Documentation/trace/ftrace.txt +++ b/Documentation/trace/ftrace.txt @@ -1842,6 +1842,89 @@ an error. # cat buffer_size_kb 85 +Snapshot +-------- +CONFIG_TRACER_SNAPSHOT makes a generic snapshot feature +available to all non latency tracers. (Latency tracers which +record max latency, such as "irqsoff" or "wakeup", can't use +this feature, since those are already using the snapshot +mechanism internally.) + +Snapshot preserves a current trace buffer at a particular point +in time without stopping tracing. Ftrace swaps the current +buffer with a spare buffer, and tracing continues in the new +current (=previous spare) buffer. + +The following debugfs files in "tracing" are related to this +feature: + + snapshot: + + This is used to take a snapshot and to read the output + of the snapshot. Echo 1 into this file to allocate a + spare buffer and to take a snapshot (swap), then read + the snapshot from this file in the same format as + "trace" (described above in the section "The File + System"). Both reads snapshot and tracing are executable + in parallel. When the spare buffer is allocated, echoing + 0 frees it, and echoing else (positive) values clear the + snapshot contents. + More details are shown in the table below. + + status\input | 0 | 1 | else | + --------------+------------+------------+------------+ + not allocated |(do nothing)| alloc+swap | EINVAL | + --------------+------------+------------+------------+ + allocated | free | swap | clear | + --------------+------------+------------+------------+ + +Here is an example of using the snapshot feature. + + # echo 1 > events/sched/enable + # echo 1 > snapshot + # cat snapshot +# tracer: nop +# +# entries-in-buffer/entries-written: 71/71 #P:8 +# +# _-----=> irqs-off +# / _----=> need-resched +# | / _---=> hardirq/softirq +# || / _--=> preempt-depth +# ||| / delay +# TASK-PID CPU# |||| TIMESTAMP FUNCTION +# | | | |||| | | + <idle>-0 [005] d... 2440.603828: sched_switch: prev_comm=swapper/5 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=snapshot-test-2 next_pid=2242 next_prio=120 + sleep-2242 [005] d... 2440.603846: sched_switch: prev_comm=snapshot-test-2 prev_pid=2242 prev_prio=120 prev_state=R ==> next_comm=kworker/5:1 next_pid=60 next_prio=120 +[...] + <idle>-0 [002] d... 2440.707230: sched_switch: prev_comm=swapper/2 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=snapshot-test-2 next_pid=2229 next_prio=120 + + # cat trace +# tracer: nop +# +# entries-in-buffer/entries-written: 77/77 #P:8 +# +# _-----=> irqs-off +# / _----=> need-resched +# | / _---=> hardirq/softirq +# || / _--=> preempt-depth +# ||| / delay +# TASK-PID CPU# |||| TIMESTAMP FUNCTION +# | | | |||| | | + <idle>-0 [007] d... 2440.707395: sched_switch: prev_comm=swapper/7 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=snapshot-test-2 next_pid=2243 next_prio=120 + snapshot-test-2-2229 [002] d... 2440.707438: sched_switch: prev_comm=snapshot-test-2 prev_pid=2229 prev_prio=120 prev_state=S ==> next_comm=swapper/2 next_pid=0 next_prio=120 +[...] + + +If you try to use this snapshot feature when current tracer is +one of the latency tracers, you will get the following results. + + # echo wakeup > current_tracer + # echo 1 > snapshot +bash: echo: write error: Device or resource busy + # cat snapshot +cat: snapshot: Device or resource busy + ----------- More details can be found in the source code, in the |