[reactos] 04/11: [NTOS:MM] Add the pool quota prototypes and some definitions

[George Bișoc]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=13cbc7fbf9197dd787259…

commit 13cbc7fbf9197dd787259d32c679049f243c13c8
Author:     George Bișoc <george.bisoc(a)reactos.org>
AuthorDate: Thu Dec 30 20:57:14 2021 +0100
Commit:     George Bișoc <george.bisoc(a)reactos.org>
CommitDate: Tue Jan 11 10:11:08 2022 +0100

    [NTOS:MM] Add the pool quota prototypes and some definitions
    
    Declare the MmRaisePoolQuota and MmReturnPoolQuota prototypes in the header and add
some definitions related to pool quotas, namely MmTotalNonPagedPoolQuota and
MmTotalPagedPoolQuota. These variables are used internally by the kernel as sort of
"containers" (for the lack of a better term)
    which uphold the amount of quotas that the Process Manager is requesting the Memory
Manager to raise or return the pool quota limit. In addition to that, add some definitions
needed for both of these functions.
    
    The definitions, MI_CHARGE_PAGED_POOL_QUOTA and MI_CHARGE_NON_PAGED_POOL_QUOTA
respectively, bear some interesting aspect. Seemingly the 0x80000 and 0x10000 values (that
would denote to 524288 and 65536 specifically) are used as quota "limits" or in
other words, thresholds that the kernel
    uses. So for example if one would want to raise the quota limit charge,
MmRaisePoolQuota will raise it so based on this formula -- NewMaxQuota = CurrentQuota +
LIMIT_VALUE. LIMIT_VALUE can be either MI_CHARGE_PAGED_POOL_QUOTA or
MI_CHARGE_NON_PAGED_POOL_QUOTA, depending a per quota pool basis.
    
    What's more interesting is that these values are pervasive in Process Manager
even. This is when quotas are to be returned back and trim the limit of the quota block if
needed, the kernel would either take the amount provided by the caller of quotas to return
or the threshold (paged or not paged)
    if the amount to return exceeds the said threshold in question.
---
 ntoskrnl/include/internal/mm.h | 28 ++++++++++++++++++++++++----
 1 file changed, 24 insertions(+), 4 deletions(-)

diff --git a/ntoskrnl/include/internal/mm.h b/ntoskrnl/include/internal/mm.h
index 654f23c6ee0..5c28d27806b 100644
--- a/ntoskrnl/include/internal/mm.h
+++ b/ntoskrnl/include/internal/mm.h
@@ -28,6 +28,9 @@ extern KMUTANT MmSystemLoadLock;
 
 extern ULONG MmNumberOfPagingFiles;
 
+extern SIZE_T MmTotalNonPagedPoolQuota;
+extern SIZE_T MmTotalPagedPoolQuota;
+
 extern PVOID MmUnloadedDrivers;
 extern PVOID MmLastUnloadedDrivers;
 extern PVOID MmTriageActionTaken;
@@ -53,6 +56,14 @@ struct _EPROCESS;
 struct _MM_RMAP_ENTRY;
 typedef ULONG_PTR SWAPENTRY;
 
+//
+// Pool Quota values
+//
+#define MI_QUOTA_NON_PAGED_NEEDED_PAGES             64
+#define MI_NON_PAGED_QUOTA_MIN_RESIDENT_PAGES       200
+#define MI_CHARGE_PAGED_POOL_QUOTA                  0x80000
+#define MI_CHARGE_NON_PAGED_POOL_QUOTA              0x10000
+
 //
 // Special IRQL value (found in assertions)
 //
@@ -646,12 +657,21 @@ MiFreePoolPages(
 
 /* pool.c *******************************************************************/
 
+_Requires_lock_held_(PspQuotaLock)
 BOOLEAN
 NTAPI
-MiRaisePoolQuota(
-    IN POOL_TYPE PoolType,
-    IN ULONG CurrentMaxQuota,
-    OUT PULONG NewMaxQuota
+MmRaisePoolQuota(
+    _In_ POOL_TYPE PoolType,
+    _In_ SIZE_T CurrentMaxQuota,
+    _Out_ PSIZE_T NewMaxQuota
+);
+
+_Requires_lock_held_(PspQuotaLock)
+VOID
+NTAPI
+MmReturnPoolQuota(
+    _In_ POOL_TYPE PoolType,
+    _In_ SIZE_T QuotaToReturn
 );
 
 /* mdl.c *********************************************************************/