Firstly you have to enable SeIncreaseWorkingSetPrivilege - to do this
you may use the function enableIncreaseWorkingSetPrivilege listed
below, it should return 0 on success - then you can use
SetProcessWorkingSetSize(GetCurrentProcess(), *NewMinSize*, *NewMaxSize*);
Working set sizes must be multiple of page size (typically 4096 bytes).
https://msdn.microsoft.com/en-us/library/ms686234
-------------------------------------------------------------
int enableIncreaseWorkingSetPrivilege()
{
int rc;
DWORD err;
HANDLE hToken;
TOKEN_PRIVILEGES privilege;
memset(&privilege, 0, sizeof(privilege));
privilege.PrivilegeCount = 1;
privilege.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;
rc = LookupPrivilegeValue(NULL, SE_INC_WORKING_SET_NAME,
&privilege.Privileges[0].Luid);
if (!rc)
return -1;
rc = OpenProcessToken(GetCurrentProcess(), TOKEN_ADJUST_PRIVILEGES,
&hToken);
if (!rc)
return -2;
rc = AdjustTokenPrivileges(hToken, 0, &privilege, sizeof(privilege),
NULL, NULL);
err = GetLastError();
CloseHandle(hToken);
if (!rc || err)
return -3;
return 0;
}
-------------------------------------------------------------
You can also compile SQLite with -DSQLITE_ZERO_MALLOC=1 and
-DSQLITE_ENABLE_MEMSYS5=1 and configure it to use buffer of locked
memory.
Locked memory won't get swapped so SQLite won't encounter page faults.
Function configSqliteMemory listed below allocs few megabytes of
memory, locks it and configures SQLite. It also increases working set
size because maximum quantity of memory that process can lock is equal
to minimum working set size (locked memory is included in the working
set).
-------------------------------------------------------------
int configSqliteMemory()
{
int rc;
void* memPtr;
SIZE_T memSize = 64 * 1024 * 1024;
SIZE_T wsMinSize, wsMaxSize;
rc = GetProcessWorkingSetSize(GetCurrentProcess(), &wsMinSize,
&wsMaxSize);
if (!rc)
return -1;
wsMinSize += memSize;
wsMaxSize += memSize;
rc = SetProcessWorkingSetSize(GetCurrentProcess(), wsMinSize,
wsMaxSize);
if (!rc)
return -2;
memPtr = VirtualAlloc(NULL, memSize, MEM_RESERVE | MEM_COMMIT,
PAGE_READWRITE);
if (!memPtr)
return -3;
rc = VirtualLock(memPtr, memSize);
if (!rc)
{
VirtualFree(memPtr, 0, MEM_RELEASE);
return -4;
}
rc = sqlite3_config(SQLITE_CONFIG_HEAP, memPtr, (int)memSize, 64);
if (rc != SQLITE_OK)
{
VirtualFree(memPtr, 0, MEM_RELEASE);
return -5;
}
return 0;
}
-------------------------------------------------------------
2018-05-27 20:03 GMT+02:00, x <tam118...@hotmail.com>:
> Starting to mess about with windows handles and pages I’ve never heard of is
> beyond my pain threshold Abrozy. Thanks anyway.
>
>
>
> ________________________________
> From: sqlite-users <sqlite-users-boun...@mailinglists.sqlite.org> on behalf
> of Abroży Nieprzełoży <abrozynieprzelozy314...@gmail.com>
> Sent: Sunday, May 27, 2018 5:23:12 PM
> To: SQLite mailing list
> Subject: Re: [sqlite] This is driving me nuts
>
> I think you can experiment with changing the the working set size
> limits and see what the effect will be.
> https://msdn.microsoft.com/en-us/library/cc441804
>
> 2018-05-27 17:09 GMT+02:00, curmudgeon <tam118...@hotmail.com>:
>> It seems the array was being optimised away. I had to initialise every
>> value
>> to get the OS to claim the RAM. Once I did that the timings for the array
>> were on a par with the vector with the second pass being slower than the
>> first.
>>
>> While that clears up that part of the mystery I'm no closer to a solution.
>> Going back to the latest set of results why is the assignments in the
>> second
>> pass taking so much longer when there's still 5+ GB of memory free?
>>
>>
>>
>> --
>> Sent from: http://sqlite.1065341.n5.nabble.com/
>> _______________________________________________
>> sqlite-users mailing list
>> sqlite-users@mailinglists.sqlite.org
>> http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
>>
> _______________________________________________
> sqlite-users mailing list
> sqlite-users@mailinglists.sqlite.org
> http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
> _______________________________________________
> sqlite-users mailing list
> sqlite-users@mailinglists.sqlite.org
> http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
>
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