PEXTERNAL_CACHE_CALLBACK_EX - NtDoc
Native API online documentation, based on the System Informer
(formerly Process Hacker) phnt
headers
// ntifs.h
PEXTERNAL_CACHE_CALLBACK_EX PexternalCacheCallbackEx;
VOID PexternalCacheCallbackEx(
PVOID ExternalCacheContext,
PCC_DIRTY_PAGES_INFO DirtyPagesInfo
)
{...}
View the official Windows Driver Kit DDI referenceNo description available.
The PEXTERNAL_CACHE_CALLBACK_EX callback function is called by the cache manager (Cc) on every lazy write scan.
ExternalCacheContext[in] Pointer to the context that identifies the external cache structure. This context was returned by CcRegisterExternalCacheEx.
DirtyPagesInfo[in] Pointer to a CC_DIRTY_PAGES_INFO structure that contains information about dirty page statistics for the external cache.
A client (file system) must register an external cache with Cc by calling CcRegisterExternalCacheEx before it can receive callbacks from Cc during lazy write scans.
The values in DirtyPagesInfo are provided by the Cc to the external cache client through this callback routine.
Targets (DirtyPageTarget and CleanLockedCachedPagesTarget) are for defining the upper limits. The client must strive to keep these metrics at or under their target value. When targets are exceeded, the client needs to aggressively bring down the corresponding metric.
Thresholds (DirtyPageThreshold and CleanLockedCachedPagesThreshold) define the hard upper limit that a client must not cross. The client must therefore pause all activities that could cause thresholds to be exceeded.