mmap failure [was: cygrunsrv + sshd + rsync = 20 times too slow -- throttled?]

[Ken Brown]

On 9/6/2021 1:12 PM, Ken Brown via Cygwin wrote:
> On 9/6/2021 11:32 AM, Corinna Vinschen via Cygwin wrote:
>> On Sep  5 09:24, Ken Brown via Cygwin wrote:
>>> On 9/4/2021 8:04 PM, Ken Brown via Cygwin wrote:
>>>> On 9/4/2021 6:58 PM, Ken Brown via Cygwin wrote:
>>>>> Here are the correct commits:
>>>>>
>>>>> 8169e39ab Cygwin: C++17: register keyword is deprecated
>>>>> 3ca80b360 Cygwin: dumper: fix up GCC pragma for g++ 11.2
>>>>> bdb7991db Cygwin: workaround a g++ 11.2 initialization bug
>>>>> 801120c1f Cygwin: loader script: add DWARF 5 sections
>>>>> d5cc66426 Cygwin: testsuite: avoid "conflicting types" gcc warning
>>>>> c2fe205b5 strstr: avoid warnings
>>>>> 76c2c7a89 ldexp/ldexpf: avoid assembler warning
>>>>> eeeb5650c Cygwin: fix declaration of RtlInitEmptyUnicodeString
>>>>>
>>>>>>
>>>>>>> So there appears to be something wrong with cygwin1.dll
>>>>>>> built with the current build tools (gcc 11.2.0, binutils
>>>>>>> 2.37, not sure what else is relevant).
>>>>
>>>> Wait a minute...I'll bet this is related to the MEM_EXTENDED_PARAMETER
>>>> initialization problem that was dealt with in commit bdb7991db.
>>>
>>> More data: When I run the test case under gdb, it succeeds.  When I run it
>>> under strace, I see VirtualAlloc2 in fhandler_dev_zero::mmap failing with
>>> windows error 87.
>>
>> Are the const's I added to the MEM_EXTENDED_PARAMETER data invalid,
>> perhaps?
> 
> I tried removing them, and I got the same error.  I also tried removing static, 
> and I tried removing both static and const.

BTW, when I reported that the test case succeeds under gdb, that only happens 
when I build the test case without optimization.  If I build with -O2, it fails 
under gdb also.  [In all my tests, I built cygwin1.dll without optimization.] 
This makes no sense to me at all.

Ken