From 0b227076d509c2facf177d7cdb67cbbb885cb661 Mon Sep 17 00:00:00 2001 From: Stephen Kitt Date: Tue, 23 Jun 2020 13:25:14 +0200 Subject: [PATCH] docs: sysctl/kernel: document random This documents the random directory, based on the behaviour seen in drivers/char/random.c. Signed-off-by: Stephen Kitt Link: https://lore.kernel.org/r/20200623112514.10650-1-steve@sk2.org Signed-off-by: Jonathan Corbet --- Documentation/admin-guide/sysctl/kernel.rst | 32 +++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst index 6d96f17..5f432f5 100644 --- a/Documentation/admin-guide/sysctl/kernel.rst +++ b/Documentation/admin-guide/sysctl/kernel.rst @@ -996,6 +996,38 @@ pty See Documentation/filesystems/devpts.rst. +random +====== + +This is a directory, with the following entries: + +* ``boot_id``: a UUID generated the first time this is retrieved, and + unvarying after that; + +* ``entropy_avail``: the pool's entropy count, in bits; + +* ``poolsize``: the entropy pool size, in bits; + +* ``urandom_min_reseed_secs``: obsolete (used to determine the minimum + number of seconds between urandom pool reseeding). + +* ``uuid``: a UUID generated every time this is retrieved (this can + thus be used to generate UUIDs at will); + +* ``write_wakeup_threshold``: when the entropy count drops below this + (as a number of bits), processes waiting to write to ``/dev/random`` + are woken up. + +If ``drivers/char/random.c`` is built with ``ADD_INTERRUPT_BENCH`` +defined, these additional entries are present: + +* ``add_interrupt_avg_cycles``: the average number of cycles between + interrupts used to feed the pool; + +* ``add_interrupt_avg_deviation``: the standard deviation seen on the + number of cycles between interrupts used to feed the pool. + + randomize_va_space ================== -- 2.7.4