Go to file
Suren Baghdasaryan 0e94682b73 psi: introduce psi monitor
Psi monitor aims to provide a low-latency short-term pressure detection
mechanism configurable by users.  It allows users to monitor psi metrics
growth and trigger events whenever a metric raises above user-defined
threshold within user-defined time window.

Time window and threshold are both expressed in usecs.  Multiple psi
resources with different thresholds and window sizes can be monitored
concurrently.

Psi monitors activate when system enters stall state for the monitored
psi metric and deactivate upon exit from the stall state.  While system
is in the stall state psi signal growth is monitored at a rate of 10
times per tracking window.  Min window size is 500ms, therefore the min
monitoring interval is 50ms.  Max window size is 10s with monitoring
interval of 1s.

When activated psi monitor stays active for at least the duration of one
tracking window to avoid repeated activations/deactivations when psi
signal is bouncing.

Notifications to the users are rate-limited to one per tracking window.

Link: http://lkml.kernel.org/r/20190319235619.260832-8-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14 19:52:48 -07:00
arch - Fix-ups 2019-05-14 10:45:03 -07:00
block for-5.2/block-20190507 2019-05-07 18:14:36 -07:00
certs
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2019-05-07 22:03:58 -07:00
Documentation psi: introduce psi monitor 2019-05-14 19:52:48 -07:00
drivers include/: refactor headers to allow kthread.h inclusion in psi_types.h 2019-05-14 19:52:48 -07:00
fs Merge branch 'akpm' (patches from Andrew) 2019-05-14 10:10:55 -07:00
include psi: introduce psi monitor 2019-05-14 19:52:48 -07:00
init init: free_initmem: poison freed init memory 2019-05-14 09:47:47 -07:00
ipc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2019-05-07 22:03:58 -07:00
kernel psi: introduce psi monitor 2019-05-14 19:52:48 -07:00
lib mm/gup: change GUP fast to use flags rather than a write 'bool' 2019-05-14 09:47:46 -07:00
LICENSES
mm mm: update references to page _refcount 2019-05-14 19:52:47 -07:00
net Merge branch 'akpm' (patches from Andrew) 2019-05-14 10:10:55 -07:00
samples samples: add .gitignore for pidfd-metadata 2019-05-10 11:50:52 +02:00
scripts gcc-plugin fix: 2019-05-13 16:01:52 -07:00
security Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-05-13 15:15:00 -07:00
sound sound updates for 5.2-rc1 2019-05-09 08:26:55 -07:00
tools pci-v5.2-changes 2019-05-14 10:30:10 -07:00
usr
virt mm/mmu_notifier: convert user range->blockable to helper function 2019-05-14 09:47:49 -07:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore .gitignore: add more all*.config patterns 2019-05-08 09:47:46 +09:00
.mailmap A reasonably busy cycle for docs, including: 2019-05-08 12:42:50 -07:00
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS - Core Frameworks 2019-05-14 10:39:08 -07:00
Makefile Kbuild updates for v5.2 2019-05-08 12:25:12 -07:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.