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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [win-pv-devel] [PATCH] Reduce time spent in the DbgPrint callback
Currently the log dispositions are serviced directly, meaning that all the
trapping for emulation is done synchronously, which is costly for
performance. This patch introduces a DPC to service the dispostions,
limiting the work done in the call back to simply copying the message
buffer and queuing the DPC.
Signed-off-by: Paul Durrant <paul.durrant@xxxxxxxxxx>
---
src/xen/log.c | 196 +++++++++++++++++++++++++++++++++++++---------------------
1 file changed, 125 insertions(+), 71 deletions(-)
diff --git a/src/xen/log.c b/src/xen/log.c
index 9b3a5e8..ed7e484 100644
--- a/src/xen/log.c
+++ b/src/xen/log.c
@@ -43,70 +43,81 @@
#define LOG_BUFFER_SIZE 256
+typedef struct _LOG_SLOT {
+ LOG_LEVEL Level;
+ CHAR Buffer[LOG_BUFFER_SIZE];
+ ULONG Offset;
+} LOG_SLOT, *PLOG_SLOT;
+
struct _LOG_DISPOSITION {
LOG_LEVEL Mask;
VOID (*Function)(PVOID, PCHAR, ULONG);
PVOID Argument;
};
-#define LOG_MAXIMUM_DISPOSITION 8
+#define LOG_NR_SLOTS 32
+#define LOG_NR_DISPOSITIONS 8
typedef struct _LOG_CONTEXT {
LONG References;
BOOLEAN Enabled;
- CHAR Buffer[LOG_BUFFER_SIZE];
- ULONG Offset;
- LOG_DISPOSITION Disposition[LOG_MAXIMUM_DISPOSITION];
+ LOG_SLOT Slot[LOG_NR_SLOTS];
+ ULONG Pending;
+ LOG_DISPOSITION Disposition[LOG_NR_DISPOSITIONS];
HIGH_LOCK Lock;
+ KDPC Dpc;
} LOG_CONTEXT, *PLOG_CONTEXT;
static LOG_CONTEXT LogContext;
-static FORCEINLINE
-__drv_maxIRQL(HIGH_LEVEL)
-__drv_raisesIRQL(HIGH_LEVEL)
-__drv_savesIRQL
-KIRQL
-__LogAcquireBuffer(
- IN PLOG_CONTEXT Context
+static FORCEINLINE VOID
+__LogFlushSlot(
+ IN PLOG_CONTEXT Context,
+ IN PLOG_SLOT Slot
)
{
- return __AcquireHighLock(&Context->Lock);
+ ULONG Index;
+
+ for (Index = 0; Index < LOG_NR_DISPOSITIONS; Index++) {
+ PLOG_DISPOSITION Disposition = &Context->Disposition[Index];
+
+ if (Slot->Level & Disposition->Mask)
+ Disposition->Function(Disposition->Argument, Slot->Buffer,
+ Slot->Offset);
+ }
+
+ RtlZeroMemory(Slot->Buffer, Slot->Offset);
+ Slot->Offset = 0;
+ Slot->Level = 0;
}
-static FORCEINLINE VOID
-__drv_maxIRQL(HIGH_LEVEL)
-__drv_requiresIRQL(HIGH_LEVEL)
-__LogReleaseBuffer(
- IN PLOG_CONTEXT Context,
- IN LOG_LEVEL Level,
- IN __drv_restoresIRQL KIRQL Irql
+static VOID
+LogFlush(
+ IN PLOG_CONTEXT Context
)
{
- ULONG Index;
+ ULONG Index;
- for (Index = 0; Index < LOG_MAXIMUM_DISPOSITION; Index++) {
- PLOG_DISPOSITION Disposition = &Context->Disposition[Index];
+ for (Index = 0; Index < Context->Pending; Index++)
+ {
+ PLOG_SLOT Slot = &Context->Slot[Index];
- if (Level & Disposition->Mask)
- Disposition->Function(Disposition->Argument, Context->Buffer,
Context->Offset);
+ __LogFlushSlot(Context, Slot);
}
- RtlZeroMemory(Context->Buffer, Context->Offset);
- Context->Offset = 0;
-
- ReleaseHighLock(&Context->Lock, Irql);
+ Context->Pending = 0;
}
static FORCEINLINE VOID
__LogPut(
- IN PLOG_CONTEXT Context,
- IN CHAR Character
+ IN PLOG_SLOT Slot,
+ IN CHAR Character
)
{
- ASSERT(Context->Offset < LOG_BUFFER_SIZE);
+ if (Slot->Offset >= LOG_BUFFER_SIZE)
+ return;
- Context->Buffer[Context->Offset++] = Character;
+ Slot->Buffer[Slot->Offset++] = Character;
}
static PCHAR
@@ -170,14 +181,14 @@ LogFormatNumber(
} while (FALSE)
static VOID
-LogWriteBuffer(
- IN PLOG_CONTEXT Context,
- IN LONG Count,
- IN const CHAR *Format,
- IN va_list Arguments
+LogWriteSlot(
+ IN PLOG_SLOT Slot,
+ IN LONG Count,
+ IN const CHAR *Format,
+ IN va_list Arguments
)
{
- CHAR Character;
+ CHAR Character;
while ((Character = *Format++) != '\0') {
UCHAR Pad = 0;
@@ -187,7 +198,7 @@ LogWriteBuffer(
BOOLEAN OppositeJustification = FALSE;
if (Character != '%') {
- __LogPut(Context, Character);
+ __LogPut(Slot, Character);
goto loop;
}
@@ -236,13 +247,13 @@ LogWriteBuffer(
WCHAR Value;
Value = va_arg(Arguments, WCHAR);
- __LogPut(Context, (CHAR)Value);
+ __LogPut(Slot, (CHAR)Value);
} else {
CHAR Value;
Value = va_arg(Arguments, CHAR);
- __LogPut(Context, Value);
+ __LogPut(Slot, Value);
}
break;
}
@@ -269,15 +280,15 @@ LogWriteBuffer(
Length = (ULONG)strlen(Buffer);
if (!OppositeJustification) {
while (Pad > Length) {
- __LogPut(Context, (ZeroPrefix) ? '0' : ' ');
+ __LogPut(Slot, (ZeroPrefix) ? '0' : ' ');
--Pad;
}
}
for (Index = 0; Index < Length; Index++)
- __LogPut(Context, Buffer[Index]);
+ __LogPut(Slot, Buffer[Index]);
if (OppositeJustification) {
while (Pad > Length) {
- __LogPut(Context, ' ');
+ __LogPut(Slot, ' ');
--Pad;
}
}
@@ -297,17 +308,17 @@ LogWriteBuffer(
if (OppositeJustification) {
while (Pad > Length) {
- __LogPut(Context, ' ');
+ __LogPut(Slot, ' ');
--Pad;
}
}
for (Index = 0; Index < Length; Index++)
- __LogPut(Context, (CHAR)Value[Index]);
+ __LogPut(Slot, (CHAR)Value[Index]);
if (!OppositeJustification) {
while (Pad > Length) {
- __LogPut(Context, ' ');
+ __LogPut(Slot, ' ');
--Pad;
}
}
@@ -323,17 +334,17 @@ LogWriteBuffer(
if (OppositeJustification) {
while (Pad > Length) {
- __LogPut(Context, ' ');
+ __LogPut(Slot, ' ');
--Pad;
}
}
for (Index = 0; Index < Length; Index++)
- __LogPut(Context, Value[Index]);
+ __LogPut(Slot, Value[Index]);
if (!OppositeJustification) {
while (Pad > Length) {
- __LogPut(Context, ' ');
+ __LogPut(Slot, ' ');
--Pad;
}
}
@@ -358,17 +369,17 @@ LogWriteBuffer(
if (OppositeJustification) {
while (Pad > Length) {
- __LogPut(Context, ' ');
+ __LogPut(Slot, ' ');
--Pad;
}
}
for (Index = 0; Index < Length; Index++)
- __LogPut(Context, (CHAR)Buffer[Index]);
+ __LogPut(Slot, (CHAR)Buffer[Index]);
if (!OppositeJustification) {
while (Pad > Length) {
- __LogPut(Context, ' ');
+ __LogPut(Slot, ' ');
--Pad;
}
}
@@ -388,17 +399,17 @@ LogWriteBuffer(
if (OppositeJustification) {
while (Pad > Length) {
- __LogPut(Context, ' ');
+ __LogPut(Slot, ' ');
--Pad;
}
}
for (Index = 0; Index < Length; Index++)
- __LogPut(Context, Buffer[Index]);
+ __LogPut(Slot, Buffer[Index]);
if (!OppositeJustification) {
while (Pad > Length) {
- __LogPut(Context, ' ');
+ __LogPut(Slot, ' ');
--Pad;
}
}
@@ -407,7 +418,7 @@ LogWriteBuffer(
break;
}
default:
- __LogPut(Context, Character);
+ __LogPut(Slot, Character);
break;
}
@@ -427,16 +438,25 @@ LogCchVPrintf(
)
{
PLOG_CONTEXT Context = &LogContext;
+ PLOG_SLOT Slot;
KIRQL Irql;
- Irql = __LogAcquireBuffer(Context);
+ AcquireHighLock(&Context->Lock, &Irql);
- LogWriteBuffer(Context,
- __min(Count, LOG_BUFFER_SIZE),
- Format,
- Arguments);
+ if (Context->Pending == ARRAYSIZE(Context->Slot))
+ LogFlush(Context);
- __LogReleaseBuffer(Context, Level, Irql);
+ Slot = &Context->Slot[Context->Pending++];
+
+ Slot->Level = Level;
+ LogWriteSlot(Slot,
+ __min(Count, LOG_BUFFER_SIZE),
+ Format,
+ Arguments);
+
+ LogFlush(Context);
+
+ ReleaseHighLock(&Context->Lock, Irql);
}
XEN_API
@@ -488,6 +508,33 @@ typedef VOID
ULONG Level
);
+static
+_Function_class_(KDEFERRED_ROUTINE)
+_IRQL_requires_max_(DISPATCH_LEVEL)
+_IRQL_requires_min_(DISPATCH_LEVEL)
+_IRQL_requires_(DISPATCH_LEVEL)
+_IRQL_requires_same_
+VOID
+LogDpc(
+ IN PKDPC Dpc,
+ IN PVOID _Context,
+ IN PVOID Argument1,
+ IN PVOID Argument2
+ )
+{
+ PLOG_CONTEXT Context = &LogContext;
+ KIRQL Irql;
+
+ UNREFERENCED_PARAMETER(_Context);
+ UNREFERENCED_PARAMETER(Dpc);
+ UNREFERENCED_PARAMETER(Argument1);
+ UNREFERENCED_PARAMETER(Argument2);
+
+ AcquireHighLock(&Context->Lock, &Irql);
+ LogFlush(Context);
+ ReleaseHighLock(&Context->Lock, Irql);
+}
+
static VOID
LogDebugPrint(
IN PANSI_STRING Ansi,
@@ -497,7 +544,7 @@ LogDebugPrint(
{
PLOG_CONTEXT Context = &LogContext;
KIRQL Irql;
- ULONG Index;
+ PLOG_SLOT Slot;
UNREFERENCED_PARAMETER(ComponentId);
@@ -518,14 +565,18 @@ LogDebugPrint(
AcquireHighLock(&Context->Lock, &Irql);
- for (Index = 0; Index < LOG_MAXIMUM_DISPOSITION; Index++) {
- PLOG_DISPOSITION Disposition = &Context->Disposition[Index];
+ if (Context->Pending == ARRAYSIZE(Context->Slot))
+ LogFlush(Context);
- if ((1 << Level) & Disposition->Mask)
- Disposition->Function(Disposition->Argument, Ansi->Buffer,
Ansi->Length);
- }
+ Slot = &Context->Slot[Context->Pending++];
+
+ Slot->Level = 1 << Level;
+ RtlCopyMemory(Slot->Buffer, Ansi->Buffer, Ansi->Length);
+ Slot->Offset = Ansi->Length;
ReleaseHighLock(&Context->Lock, Irql);
+
+ KeInsertQueueDpc(&Context->Dpc, NULL, NULL);
}
VOID
@@ -540,6 +591,7 @@ LogTeardown(
Context->Enabled = FALSE;
}
+ RtlZeroMemory(&Context->Dpc, sizeof (KDPC));
RtlZeroMemory(&Context->Lock, sizeof (HIGH_LOCK));
(VOID) InterlockedDecrement(&Context->References);
@@ -567,7 +619,7 @@ LogAddDisposition(
AcquireHighLock(&Context->Lock, &Irql);
status = STATUS_UNSUCCESSFUL;
- for (Index = 0; Index < LOG_MAXIMUM_DISPOSITION; Index++) {
+ for (Index = 0; Index < LOG_NR_DISPOSITIONS; Index++) {
*Disposition = &Context->Disposition[Index];
if ((*Disposition)->Mask == 0) {
@@ -612,7 +664,7 @@ LogRemoveDisposition(
AcquireHighLock(&Context->Lock, &Irql);
- for (Index = 0; Index < LOG_MAXIMUM_DISPOSITION; Index++) {
+ for (Index = 0; Index < LOG_NR_DISPOSITIONS; Index++) {
if (&Context->Disposition[Index] != Disposition)
continue;
@@ -749,6 +801,8 @@ LogInitialize(
InitializeHighLock(&Context->Lock);
+ KeInitializeDpc(&Context->Dpc, LogDpc, NULL);
+
if (__LogDbgPrintCallbackEnable()) {
status = DbgSetDebugPrintCallback(LogDebugPrint, TRUE);
--
2.5.3
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