Re: arm64 fork/swap data corruptions: A ~110 line C program demonstrating an example (Pine64+ 2GB context) [Corrected subject: arm64!]

2017-03-27 Thread Mark Millard
On 2017-Mar-21, at 7:21 PM, Mark Millard wrote: > On 2017-Mar-18, at 9:10 PM, Mark Millard wrote: > >> >> On 2017-Mar-18, at 5:53 PM, Mark Millard wrote: >> >>> A new, significant discovery follows. . . >>> >>> While checking out use of procstat -v I ran >>> into the following common

Re: arm64 fork/swap data corruptions: A ~110 line C program demonstrating an example (Pine64+ 2GB context) [Corrected subject: arm64!]

2017-03-21 Thread Mark Millard
On 2017-Mar-18, at 9:10 PM, Mark Millard wrote: > > On 2017-Mar-18, at 5:53 PM, Mark Millard wrote: > >> A new, significant discovery follows. . . >> >> While checking out use of procstat -v I ran >> into the following common property for the 3 >>

Re: arm64 fork/swap data corruptions: A ~110 line C program demonstrating an example (Pine64+ 2GB context) [Corrected subject: arm64!]

2017-03-18 Thread Mark Millard
On 2017-Mar-18, at 5:53 PM, Mark Millard wrote: > A new, significant discovery follows. . . > > While checking out use of procstat -v I ran > into the following common property for the 3 > programs that I looked at: > > A) My small test program that fails for > a

Re: arm64 fork/swap data corruptions: A ~110 line C program demonstrating an example (Pine64+ 2GB context) [Corrected subject: arm64!]

2017-03-18 Thread Mark Millard
A new, significant discovery follows. . . While checking out use of procstat -v I ran into the following common property for the 3 programs that I looked at: A) My small test program that fails for a dynamically allocated space. B) sh reporting Failed assertion: "tsd_booted". C) su

Re: arm64 fork/swap data corruptions: A ~110 line C program demonstrating an example (Pine64+ 2GB context) [Corrected subject: arm64!]

2017-03-18 Thread Mark Millard
[Summary: I've now tested on a rpi3 in addition to a pine64+ 2GB. Both contexts show the problem.] On 2017-Mar-16, at 2:07 AM, Mark Millard wrote: > On 2017-Mar-15, at 11:07 PM, Scott Bennett wrote: > >> Mark Millard wrote: >> >>> [Something strange happened to the automatic CC: fill-in for

Re: arm64 fork/swap data corruptions: A ~110 line C program demonstrating an example (Pine64+ 2GB context) [Corrected subject: arm64!]

2017-03-16 Thread Scott Bennett
Mark Millard wrote: > [Something strange happened to the automatic CC: fill-in for my original > reply. Also I should have mentioned that for my test program if a > variant is made that does not fork the swapping works fine.] > > On 2017-Mar-15, at 9:37 AM, Mark Millard wrote: > > > On

Re: arm64 fork/swap data corruptions: A ~110 line C program demonstrating an example (Pine64+ 2GB context) [Corrected subject: arm64!]

2017-03-16 Thread Mark Millard
On 2017-Mar-15, at 11:07 PM, Scott Bennett wrote: > Mark Millard wrote: > >> [Something strange happened to the automatic CC: fill-in for my original >> reply. Also I should have mentioned that for my test program if a >> variant is made that does not fork the swapping works fine.] >> >> On

Re: arm64 fork/swap data corruptions: A ~110 line C program demonstrating an example (Pine64+ 2GB context) [Corrected subject: arm64!]

2017-03-15 Thread Mark Millard
[Something strange happened to the automatic CC: fill-in for my original reply. Also I should have mentioned that for my test program if a variant is made that does not fork the swapping works fine.] On 2017-Mar-15, at 9:37 AM, Mark Millard wrote: > On 2017-Mar-15, at 6:15 AM, Scott Bennett

Re: arm64 fork/swap data corruptions: A ~110 line C program demonstrating an example (Pine64+ 2GB context) [Corrected subject: arm64!]

2017-03-14 Thread Mark Millard
A single Byte access to a 4K Byte aligned region between the fork and wait/sleep/swap-out prevents that specific 4K Byte region from having the (bad) zeros. Sounds like a page sized unit of behavior to me. Details follow. On 2017-Mar-14, at 3:28 PM, Mark Millard wrote: >

Re: arm64 fork/swap data corruptions: A ~110 line C program demonstrating an example (Pine64+ 2GB context) [Corrected subject: arm64!]

2017-03-14 Thread Mark Millard
On 2017-Mar-14, at 4:44 PM, Bernd Walter wrote: > On Tue, Mar 14, 2017 at 03:28:53PM -0700, Mark Millard wrote: >> [test_check() between the fork and the wait/sleep prevents the >> failure from occurring. Even a small access to the memory at >> that stage prevents the

Re: arm64 fork/swap data corruptions: A ~110 line C program demonstrating an example (Pine64+ 2GB context) [Corrected subject: arm64!]

2017-03-14 Thread Bernd Walter
On Tue, Mar 14, 2017 at 03:28:53PM -0700, Mark Millard wrote: > [test_check() between the fork and the wait/sleep prevents the > failure from occurring. Even a small access to the memory at > that stage prevents the failure. Details follow.] Maybe a stupid question, since you might have written

Re: arm64 fork/swap data corruptions: A ~110 line C program demonstrating an example (Pine64+ 2GB context) [Corrected subject: arm64!]

2017-03-14 Thread Mark Millard
[test_check() between the fork and the wait/sleep prevents the failure from occurring. Even a small access to the memory at that stage prevents the failure. Details follow.] On 2017-Mar-14, at 11:07 AM, Mark Millard wrote: > [This is just a correction to the subject-line