[Bug 57224] New: Strange Behavior with >64 Processing Cores

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=57224

Bug ID: 57224
           Summary: Strange Behavior with >64 Processing Cores
           Product: Wine
           Version: unspecified
          Hardware: x86-64
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: ntdll
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

Created attachment 77143
  --> https://bugs.winehq.org/attachment.cgi?id=77143
Compiled Microsoft Sample code to test API

I've been spending the last few weeks trying to figre out why Photoshop crashes
with >64 threads, unless one disables multithreading outright by deleting
MultiProcessor Support.pbx (which is actually a dll).

After disassembling the pbx file, and debugging Photoshop with x64dbg (under
wine) I determine that the crash occurs briefly after calling
GetLogicalProcessorInformation from Kernel32.dll. The crash occurs after the
return of the number of logical processors, so it's not the actual function
crashing, just that it is returning a value that causes an issue.

I then proceeded to test the API with this sampel code (I attached a compiled
version)
https://learn.microsoft.com/en-us/windows/win32/api/sysinfoapi/nf-sysinfoapi...
, and compare the output across systems. On Windows (& wine <64 CPUs), the
number of logical processors works as expected, as does cores.

When we cross the 64 CPU barrier, something strange happens (which I assume
causes the crash). We get 65 cores and 64 threads, which is impossible, from
stepping through the debugger, I confirm that Photoshop also gets a 65 count.

GetLogicalProcessorInformation results:
Number of NUMA nodes: 1
Number of physical processor packages: 1
Number of processor cores: 65
Number of logical processors: 64
Number of processor L1/L2/L3 caches: 130/65/9

Any ideas what's going wrong here? I understand that wine doesn't support >64
threads, but it seems like an off by 1 error.

[Bug 57224] Strange Behavior with >64 Processing Cores

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=57224

--- Comment #1 from EricParker  ---
From testing (have tested on my test script, but not on photoshop yet), adding
this to prevent the 65th core from getting a relationprocessorcore fixes the 65
issue. This is probably suboptimal as the fact that it only goes to 65 implies
there is a check somewhere higher up.

if (phys_core < 64) {

// by adding this if statement, the output now behaves
identically to windows

if (!logical_proc_info_add_by_id( RelationProcessorCore,
phys_core, thread_mask ))
                {
                    fclose(fcpu_list);
                    return STATUS_NO_MEMORY;
                }
            }

[Bug 57224] Strange Behavior with >64 Processing Cores

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=57224

--- Comment #2 from EricParker  ---
Created attachment 77159
  --> https://bugs.winehq.org/attachment.cgi?id=77159
Patch to fix Wine with >64 cores

Attached diffs for that patch.