diff options
author | Peter Zijlstra <peterz@infradead.org> | 2020-11-26 13:16:55 +0100 |
---|---|---|
committer | Peter Zijlstra <peterz@infradead.org> | 2020-11-26 13:16:55 +0100 |
commit | 20c7775aecea04d8ca322039969d49dcf568e0e9 (patch) | |
tree | 138c057839197c9021043353e994815c0250e669 /Documentation/ABI/testing/dev-kmsg | |
parent | 306e3e91edf1c6739a55312edd110d298ff498dd (diff) | |
parent | fa02fcd94b0c8dff6cc65714510cf25ad194b90d (diff) |
Merge remote-tracking branch 'origin/master' into perf/core
Further perf/core patches will depend on:
d3f7b1bb2040 ("mm/gup: fix gup_fast with dynamic page table folding")
which is already in Linus' tree.
Diffstat (limited to 'Documentation/ABI/testing/dev-kmsg')
-rw-r--r-- | Documentation/ABI/testing/dev-kmsg | 27 |
1 files changed, 17 insertions, 10 deletions
diff --git a/Documentation/ABI/testing/dev-kmsg b/Documentation/ABI/testing/dev-kmsg index 3c0bb76e3417..a377b6c093c9 100644 --- a/Documentation/ABI/testing/dev-kmsg +++ b/Documentation/ABI/testing/dev-kmsg @@ -6,6 +6,7 @@ Description: The /dev/kmsg character device node provides userspace access to the kernel's printk buffer. Injecting messages: + Every write() to the opened device node places a log entry in the kernel's printk buffer. @@ -21,6 +22,7 @@ Description: The /dev/kmsg character device node provides userspace access the messages can always be reliably determined. Accessing the buffer: + Every read() from the opened device node receives one record of the kernel's printk buffer. @@ -48,6 +50,7 @@ Description: The /dev/kmsg character device node provides userspace access if needed, without limiting the interface to a single reader. The device supports seek with the following parameters: + SEEK_SET, 0 seek to the first entry in the buffer SEEK_END, 0 @@ -87,18 +90,22 @@ Description: The /dev/kmsg character device node provides userspace access readable context of the message, for reliable processing in userspace. - Example: - 7,160,424069,-;pci_root PNP0A03:00: host bridge window [io 0x0000-0x0cf7] (ignored) - SUBSYSTEM=acpi - DEVICE=+acpi:PNP0A03:00 - 6,339,5140900,-;NET: Registered protocol family 10 - 30,340,5690716,-;udevd[80]: starting version 181 + Example:: + + 7,160,424069,-;pci_root PNP0A03:00: host bridge window [io 0x0000-0x0cf7] (ignored) + SUBSYSTEM=acpi + DEVICE=+acpi:PNP0A03:00 + 6,339,5140900,-;NET: Registered protocol family 10 + 30,340,5690716,-;udevd[80]: starting version 181 The DEVICE= key uniquely identifies devices the following way: - b12:8 - block dev_t - c127:3 - char dev_t - n8 - netdev ifindex - +sound:card0 - subsystem:devname + + ============ ================= + b12:8 block dev_t + c127:3 char dev_t + n8 netdev ifindex + +sound:card0 subsystem:devname + ============ ================= The flags field carries '-' by default. A 'c' indicates a fragment of a line. Note, that these hints about continuation |