Support huge pages on Windows

Add support for huge pages (called large pages on Windows) to the
Windows build.

This (probably) breaks compatibility with Windows versions prior to
Windows 2003 or Windows Vista.

Authors: Takayuki Tsunakawa and Thomas Munro
Reviewed by: Magnus Hagander, Amit Kapila
This commit is contained in:
Magnus Hagander 2018-01-21 15:40:46 +01:00
parent 5c15a54e85
commit 1cc4f536ef
4 changed files with 204 additions and 22 deletions

View File

@ -1369,14 +1369,26 @@ include_dir 'conf.d'
</para>
<para>
At present, this feature is supported only on Linux. The setting is
ignored on other systems when set to <literal>try</literal>.
At present, this feature is supported only on Linux and Windows. The
setting is ignored on other systems when set to <literal>try</literal>.
</para>
<para>
The use of huge pages results in smaller page tables and less CPU time
spent on memory management, increasing performance. For more details,
see <xref linkend="linux-huge-pages"/>.
spent on memory management, increasing performance. For more details about
using huge pages on Linux, see <xref linkend="linux-huge-pages"/>.
</para>
<para>
Huge pages are known as large pages on Windows. To use them, you need to
assign the user right Lock Pages in Memory to the Windows user account
that runs <productname>PostgreSQL</productname>.
You can use Windows Group Policy tool (gpedit.msc) to assign the user right
Lock Pages in Memory.
To start the database server on the command prompt as a standalone process,
not as a Windows service, the command prompt must be run as an administrator
User Access Control (UAC) must be disabled. When the UAC is enabled, the normal
command prompt revokes the user right Lock Pages in Memory when started.
</para>
<para>

View File

@ -21,6 +21,7 @@ HANDLE UsedShmemSegID = INVALID_HANDLE_VALUE;
void *UsedShmemSegAddr = NULL;
static Size UsedShmemSegSize = 0;
static bool EnableLockPagesPrivilege(int elevel);
static void pgwin32_SharedMemoryDelete(int status, Datum shmId);
/*
@ -103,6 +104,66 @@ PGSharedMemoryIsInUse(unsigned long id1, unsigned long id2)
return true;
}
/*
* EnableLockPagesPrivilege
*
* Try to acquire SeLockMemoryPrivilege so we can use large pages.
*/
static bool
EnableLockPagesPrivilege(int elevel)
{
HANDLE hToken;
TOKEN_PRIVILEGES tp;
LUID luid;
if (!OpenProcessToken(GetCurrentProcess(), TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY, &hToken))
{
ereport(elevel,
(errmsg("could not enable Lock Pages in Memory user right: error code %lu", GetLastError()),
errdetail("Failed system call was %s.", "OpenProcessToken")));
return FALSE;
}
if (!LookupPrivilegeValue(NULL, SE_LOCK_MEMORY_NAME, &luid))
{
ereport(elevel,
(errmsg("could not enable Lock Pages in Memory user right: error code %lu", GetLastError()),
errdetail("Failed system call was %s.", "LookupPrivilegeValue")));
CloseHandle(hToken);
return FALSE;
}
tp.PrivilegeCount = 1;
tp.Privileges[0].Luid = luid;
tp.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;
if (!AdjustTokenPrivileges(hToken, FALSE, &tp, 0, NULL, NULL))
{
ereport(elevel,
(errmsg("could not enable Lock Pages in Memory user right: error code %lu", GetLastError()),
errdetail("Failed system call was %s.", "AdjustTokenPrivileges")));
CloseHandle(hToken);
return FALSE;
}
if (GetLastError() != ERROR_SUCCESS)
{
if (GetLastError() == ERROR_NOT_ALL_ASSIGNED)
ereport(elevel,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("could not enable Lock Pages in Memory user right"),
errhint("Assign Lock Pages in Memory user right to the Windows user account which runs PostgreSQL.")));
else
ereport(elevel,
(errmsg("could not enable Lock Pages in Memory user right: error code %lu", GetLastError()),
errdetail("Failed system call was %s.", "AdjustTokenPrivileges")));
CloseHandle(hToken);
return FALSE;
}
CloseHandle(hToken);
return TRUE;
}
/*
* PGSharedMemoryCreate
@ -127,11 +188,9 @@ PGSharedMemoryCreate(Size size, bool makePrivate, int port,
int i;
DWORD size_high;
DWORD size_low;
if (huge_pages == HUGE_PAGES_ON)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("huge pages not supported on this platform")));
SIZE_T largePageSize = 0;
Size orig_size = size;
DWORD flProtect = PAGE_READWRITE;
/* Room for a header? */
Assert(size > MAXALIGN(sizeof(PGShmemHeader)));
@ -140,6 +199,35 @@ PGSharedMemoryCreate(Size size, bool makePrivate, int port,
UsedShmemSegAddr = NULL;
if (huge_pages == HUGE_PAGES_ON || huge_pages == HUGE_PAGES_TRY)
{
/* Does the processor support large pages? */
largePageSize = GetLargePageMinimum();
if (largePageSize == 0)
{
ereport(huge_pages == HUGE_PAGES_ON ? FATAL : DEBUG1,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("the processor does not support large pages")));
ereport(DEBUG1,
(errmsg("disabling huge pages")));
}
else if (!EnableLockPagesPrivilege(huge_pages == HUGE_PAGES_ON ? FATAL : DEBUG1))
{
ereport(DEBUG1,
(errmsg("disabling huge pages")));
}
else
{
/* Huge pages available and privilege enabled, so turn on */
flProtect = PAGE_READWRITE | SEC_COMMIT | SEC_LARGE_PAGES;
/* Round size up as appropriate. */
if (size % largePageSize != 0)
size += largePageSize - (size % largePageSize);
}
}
retry:
#ifdef _WIN64
size_high = size >> 32;
#else
@ -163,16 +251,35 @@ PGSharedMemoryCreate(Size size, bool makePrivate, int port,
hmap = CreateFileMapping(INVALID_HANDLE_VALUE, /* Use the pagefile */
NULL, /* Default security attrs */
PAGE_READWRITE, /* Memory is Read/Write */
flProtect,
size_high, /* Size Upper 32 Bits */
size_low, /* Size Lower 32 bits */
szShareMem);
if (!hmap)
ereport(FATAL,
(errmsg("could not create shared memory segment: error code %lu", GetLastError()),
errdetail("Failed system call was CreateFileMapping(size=%zu, name=%s).",
size, szShareMem)));
{
if (GetLastError() == ERROR_NO_SYSTEM_RESOURCES &&
huge_pages == HUGE_PAGES_TRY &&
(flProtect & SEC_LARGE_PAGES) != 0)
{
elog(DEBUG1, "CreateFileMapping(%zu) with SEC_LARGE_PAGES failed, "
"huge pages disabled",
size);
/*
* Use the original size, not the rounded-up value, when falling back
* to non-huge pages.
*/
size = orig_size;
flProtect = PAGE_READWRITE;
goto retry;
}
else
ereport(FATAL,
(errmsg("could not create shared memory segment: error code %lu", GetLastError()),
errdetail("Failed system call was CreateFileMapping(size=%zu, name=%s).",
size, szShareMem)));
}
/*
* If the segment already existed, CreateFileMapping() will return a

View File

@ -3913,7 +3913,7 @@ static struct config_enum ConfigureNamesEnum[] =
{
{"huge_pages", PGC_POSTMASTER, RESOURCES_MEM,
gettext_noop("Use of huge pages on Linux."),
gettext_noop("Use of huge pages on Linux or Windows."),
NULL
},
&huge_pages,

View File

@ -144,6 +144,7 @@ static void WINAPI pgwin32_ServiceHandler(DWORD);
static void WINAPI pgwin32_ServiceMain(DWORD, LPTSTR *);
static void pgwin32_doRunAsService(void);
static int CreateRestrictedProcess(char *cmd, PROCESS_INFORMATION *processInfo, bool as_service);
static PTOKEN_PRIVILEGES GetPrivilegesToDelete(HANDLE hToken);
#endif
static pgpid_t get_pgpid(bool is_status_request);
@ -1623,11 +1624,6 @@ typedef BOOL (WINAPI * __SetInformationJobObject) (HANDLE, JOBOBJECTINFOCLASS, L
typedef BOOL (WINAPI * __AssignProcessToJobObject) (HANDLE, HANDLE);
typedef BOOL (WINAPI * __QueryInformationJobObject) (HANDLE, JOBOBJECTINFOCLASS, LPVOID, DWORD, LPDWORD);
/* Windows API define missing from some versions of MingW headers */
#ifndef DISABLE_MAX_PRIVILEGE
#define DISABLE_MAX_PRIVILEGE 0x1
#endif
/*
* Create a restricted token, a job object sandbox, and execute the specified
* process with it.
@ -1650,6 +1646,7 @@ CreateRestrictedProcess(char *cmd, PROCESS_INFORMATION *processInfo, bool as_ser
HANDLE restrictedToken;
SID_IDENTIFIER_AUTHORITY NtAuthority = {SECURITY_NT_AUTHORITY};
SID_AND_ATTRIBUTES dropSids[2];
PTOKEN_PRIVILEGES delPrivs;
/* Functions loaded dynamically */
__CreateRestrictedToken _CreateRestrictedToken = NULL;
@ -1708,14 +1705,21 @@ CreateRestrictedProcess(char *cmd, PROCESS_INFORMATION *processInfo, bool as_ser
return 0;
}
/* Get list of privileges to remove */
delPrivs = GetPrivilegesToDelete(origToken);
if (delPrivs == NULL)
/* Error message already printed */
return 0;
b = _CreateRestrictedToken(origToken,
DISABLE_MAX_PRIVILEGE,
0,
sizeof(dropSids) / sizeof(dropSids[0]),
dropSids,
0, NULL,
delPrivs->PrivilegeCount, delPrivs->Privileges,
0, NULL,
&restrictedToken);
free(delPrivs);
FreeSid(dropSids[1].Sid);
FreeSid(dropSids[0].Sid);
CloseHandle(origToken);
@ -1832,6 +1836,65 @@ CreateRestrictedProcess(char *cmd, PROCESS_INFORMATION *processInfo, bool as_ser
*/
return r;
}
/*
* Get a list of privileges to delete from the access token. We delete all privileges
* except SeLockMemoryPrivilege which is needed to use large pages, and
* SeChangeNotifyPrivilege which is enabled by default in DISABLE_MAX_PRIVILEGE.
*/
static PTOKEN_PRIVILEGES
GetPrivilegesToDelete(HANDLE hToken)
{
int i, j;
DWORD length;
PTOKEN_PRIVILEGES tokenPrivs;
LUID luidLockPages;
LUID luidChangeNotify;
if (!LookupPrivilegeValue(NULL, SE_LOCK_MEMORY_NAME, &luidLockPages) ||
!LookupPrivilegeValue(NULL, SE_CHANGE_NOTIFY_NAME, &luidChangeNotify))
{
write_stderr(_("%s: could not get LUIDs for privileges: error code %lu\n"),
progname, (unsigned long) GetLastError());
return NULL;
}
if (!GetTokenInformation(hToken, TokenPrivileges, NULL, 0, &length) &&
GetLastError() != ERROR_INSUFFICIENT_BUFFER)
{
write_stderr(_("%s: could not get token information: error code %lu\n"),
progname, (unsigned long) GetLastError());
return NULL;
}
tokenPrivs = (PTOKEN_PRIVILEGES) malloc(length);
if (tokenPrivs == NULL)
{
write_stderr(_("%s: out of memory\n"), progname);
return NULL;
}
if (!GetTokenInformation(hToken, TokenPrivileges, tokenPrivs, length, &length))
{
write_stderr(_("%s: could not get token information: error code %lu\n"),
progname, (unsigned long) GetLastError());
free(tokenPrivs);
return NULL;
}
for (i = 0; i < tokenPrivs->PrivilegeCount; i++)
{
if (memcmp(&tokenPrivs->Privileges[i].Luid, &luidLockPages, sizeof(LUID)) == 0 ||
memcmp(&tokenPrivs->Privileges[i].Luid, &luidChangeNotify, sizeof(LUID)) == 0)
{
for (j = i; j < tokenPrivs->PrivilegeCount - 1; j++)
tokenPrivs->Privileges[j] = tokenPrivs->Privileges[j + 1];
tokenPrivs->PrivilegeCount--;
}
}
return tokenPrivs;
}
#endif /* WIN32 */
static void