Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 13 Oct 2017 15:28:23 +0000
From:      bugzilla-noreply@freebsd.org
To:        freebsd-bugs@FreeBSD.org
Subject:   [Bug 221356] [patch] Improve swapon_check_swzone() function in swap_pager.c
Message-ID:  <bug-221356-8-znSjPzGyTE@https.bugs.freebsd.org/bugzilla/>
In-Reply-To: <bug-221356-8@https.bugs.freebsd.org/bugzilla/>
References:  <bug-221356-8@https.bugs.freebsd.org/bugzilla/>

next in thread | previous in thread | raw e-mail | index | archive | help
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D221356

--- Comment #12 from Konstantin Belousov <kib@FreeBSD.org> ---
(In reply to ota from comment #11)
NO_SWAPPING and vm_swap_enabled control the swap-out activity, this is the
action almost unrelated to the page swapping.  If the swap pager zones are =
left
NULL, then pageout (not swapout) would trap when pagedaemon tries to page o=
ut
anonymous memory.  For the same reason the vm_swap_enabled variable cannot =
be
used to avoid the issue, the variable control the swapping.

In the modern FreeBSD, the process is considered swapped out when all its
threads kernel stacks are marked as pageable.  In this state, the process'
thread is never allowed to be made runnable.  Idea is that non-running proc=
ess
does not reference its private pages and they are eventually get paged out.

So the two later patches need serious rework.  The first patch is still not
re-merged with the latest HEAD code.  I only found one bit which might be t=
aken
as is from it, see https://reviews.freebsd.org/D12660.

--=20
You are receiving this mail because:
You are the assignee for the bug.=



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?bug-221356-8-znSjPzGyTE>