The arm64 fork-then-swap-out-then-swap-in failures: a program source for exploring them

[Mark Millard]

On 2017-Apr-19, at 10:28 AM, Mark Millard <markmi at dsl-only.net> wrote:

> On 2017-Apr-18, at 11:16 AM, Jia-Shiun Li <jiashiun at gmail.com> wrote:
> 
>> just noticed that rpi3 wiki page still has outdated issue info regarding
>> this (the jemalloc error). Anyone to help update it?
>> 
>> https://wiki.freebsd.org/arm64/rpi3
> 
> stable/11 is still in process for the fork handling fixes.
> 
> One of the 2 fixes to fork behavior has just been MFC'd:
> -r313772 from head is now -r317147 in stable/11 . So
> interrupts will no longer trash the sp_el0 register.
> 
> There is still -r316679 from head to go so that
> Copy-On-Write would work for fork. (The defect
> may be more general than just being for fork.)

stable/11 -r317354 completes the fixes:

Author: kib
Date: Mon Apr 24 07:52:44 2017
New Revision: 317354
URL: 
https://svnweb.freebsd.org/changeset/base/317354


Log:
  MFC r316679:
  Do not lose dirty bits for removing PROT_WRITE on arm64.

Modified:
  stable/11/sys/arm64/arm64/pmap.c
Directory Properties:
  stable/11/   (props changed)

. . .


See:

https://lists.freebsd.org/pipermail/svn-src-stable-11/2017-April/003041.html

So now the old rpi3 wiki page material is only for
masking some of the problems in older contexts for
12 or for older contexts for 11.

[I've not been running 11, just 12.]


===
Mark Millard
markmi at dsl-only.net