[libcamera-devel] [PATCH v3 3/4] libcamera: pipeline-handler: Consider max in-flight requests constraint
Umang Jain
umang.jain at ideasonboard.com
Sun Jun 19 22:40:23 CEST 2022
This patch introduces a new constraint in the pipeline handler base
class which allows various derived pipeline handlers to set and
restrict the number of maximum in-flight requests that can be queued to
the underlying components.
The pipeline handler is now equipped with the responsibility of not to
over queue the requests to the underlying layers. The derived
pipeline handler (or even IPA) can also have various kind of requests
queue(arrays, queues or ring-buffer) hence, it might be an issue where
the application queues the requests at a rate where these kind of
queues can over-flow. The patch ensures that the base pipeline-handler
will never let the requests overflow to underlying layers, once the
derived pipeline handler sets its maximum capacity of handling
in-flight requests using PipelineHandler::setMaxQueueRequests().
The queue request management introduced in the pipeline handler base
class is now used by the IPU3 pipeline handler.
Signed-off-by: Umang Jain <umang.jain at ideasonboard.com>
---
include/libcamera/internal/pipeline_handler.h | 6 ++
include/libcamera/ipa/ipu3.mojom | 1 +
src/ipa/ipu3/ipa_context.cpp | 18 ++++--
src/ipa/ipu3/ipa_context.h | 5 +-
src/ipa/ipu3/ipu3.cpp | 3 +-
src/libcamera/pipeline/ipu3/ipu3.cpp | 9 +++
src/libcamera/pipeline_handler.cpp | 61 ++++++++++++++++++-
7 files changed, 94 insertions(+), 9 deletions(-)
diff --git a/include/libcamera/internal/pipeline_handler.h b/include/libcamera/internal/pipeline_handler.h
index c3e4c258..5a319011 100644
--- a/include/libcamera/internal/pipeline_handler.h
+++ b/include/libcamera/internal/pipeline_handler.h
@@ -67,9 +67,12 @@ public:
const char *name() const { return name_; }
+ uint32_t maxQueueRequests() { return maxQueueRequests_; }
+
protected:
void registerCamera(std::shared_ptr<Camera> camera);
void hotplugMediaDevice(MediaDevice *media);
+ void setMaxQueueRequests(uint32_t maxRequests);
virtual int queueRequestDevice(Camera *camera, Request *request) = 0;
virtual void stopDevice(Camera *camera) = 0;
@@ -88,6 +91,9 @@ private:
std::queue<Request *> waitingRequests_;
+ uint32_t maxQueueRequests_;
+ uint32_t requestsQueueCounter_;
+
const char *name_;
Mutex lock_;
diff --git a/include/libcamera/ipa/ipu3.mojom b/include/libcamera/ipa/ipu3.mojom
index d1b1c6b8..3e7bbc6e 100644
--- a/include/libcamera/ipa/ipu3.mojom
+++ b/include/libcamera/ipa/ipu3.mojom
@@ -14,6 +14,7 @@ struct IPAConfigInfo {
libcamera.ControlInfoMap lensControls;
libcamera.Size bdsOutputSize;
libcamera.Size iif;
+ uint32 maxQueueRequests;
};
interface IPAIPU3Interface {
diff --git a/src/ipa/ipu3/ipa_context.cpp b/src/ipa/ipu3/ipa_context.cpp
index 60c58b97..564f8e6c 100644
--- a/src/ipa/ipu3/ipa_context.cpp
+++ b/src/ipa/ipu3/ipa_context.cpp
@@ -248,7 +248,7 @@ IPAFrameContext::IPAFrameContext(uint32_t id, const ControlList &reqControls)
* \brief FCQueue constructor
*/
FCQueue::FCQueue()
- : latestFC_(0), oldestFC_(0), isFull_(false)
+ : latestFC_(0), oldestFC_(0), size_(0), isFull_(false)
{
}
@@ -269,7 +269,7 @@ FCQueue::FCQueue()
IPAFrameContext *FCQueue::get(uint32_t frame)
{
if (latestFC_ && frame <= latestFC_) {
- IPAFrameContext &frameContext = this->at(frame % kMaxFrameContexts);
+ IPAFrameContext &frameContext = this->at(frame % size_);
if (frame != frameContext.frame)
LOG(IPAIPU3, Warning)
<< "Got wrong frame context for frame " << frame;
@@ -287,10 +287,10 @@ IPAFrameContext *FCQueue::get(uint32_t frame)
latestFC_ = frame;
/* Check if the queue is full to avoid over-queueing later */
- if (oldestFC_ && latestFC_ - oldestFC_ >= kMaxFrameContexts - 1)
+ if (oldestFC_ && latestFC_ - oldestFC_ >= size_ - 1)
isFull_ = true;
- return &this->at(latestFC_ % kMaxFrameContexts);
+ return &this->at(latestFC_ % size_);
}
}
@@ -329,6 +329,7 @@ void FCQueue::completeFrame(uint32_t frame)
*/
void FCQueue::setSize(uint32_t size)
{
+ size_ = size;
resize(size);
}
@@ -338,6 +339,12 @@ void FCQueue::setSize(uint32_t size)
* \return True of FCQueue is full, False otherwise
*/
+/**
+ * \fn FCQueue::size()
+ * \brief The number of IPAFrameContext(s) FCQueue handles
+ * \return Returns the size of FCQueue
+ */
+
/**
* \brief Clear the FCQueue by resetting all the entries in the ring-buffer
*/
@@ -345,6 +352,9 @@ void FCQueue::reset()
{
clear();
+ if (size_)
+ setSize(size_);
+
isFull_ = false;
latestFC_ = 0;
diff --git a/src/ipa/ipu3/ipa_context.h b/src/ipa/ipu3/ipa_context.h
index 52a0b5e7..0da2ad26 100644
--- a/src/ipa/ipu3/ipa_context.h
+++ b/src/ipa/ipu3/ipa_context.h
@@ -21,9 +21,6 @@ namespace libcamera {
namespace ipa::ipu3 {
-/* Maximum number of frame contexts to be held */
-static constexpr uint32_t kMaxFrameContexts = 16;
-
struct IPASessionConfiguration {
struct {
ipu3_uapi_grid_config bdsGrid;
@@ -100,10 +97,12 @@ public:
IPAFrameContext *get(uint32_t frame);
bool isFull() { return isFull_; }
+ uint32_t size() { return size_; }
private:
uint32_t latestFC_;
uint32_t oldestFC_;
+ uint32_t size_;
bool isFull_;
};
diff --git a/src/ipa/ipu3/ipu3.cpp b/src/ipa/ipu3/ipu3.cpp
index 15070fa0..3218df49 100644
--- a/src/ipa/ipu3/ipu3.cpp
+++ b/src/ipa/ipu3/ipu3.cpp
@@ -458,8 +458,9 @@ int IPAIPU3::configure(const IPAConfigInfo &configInfo,
/* Clean IPAActiveState at each reconfiguration. */
context_.activeState = {};
+
context_.frameContexts.reset();
- context_.frameContexts.setSize(kMaxFrameContexts);
+ context_.frameContexts.setSize(configInfo.maxQueueRequests);
if (!validateSensorControls()) {
LOG(IPAIPU3, Error) << "Sensor control validation failed.";
diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp
index b7dda282..d599fb95 100644
--- a/src/libcamera/pipeline/ipu3/ipu3.cpp
+++ b/src/libcamera/pipeline/ipu3/ipu3.cpp
@@ -672,6 +672,15 @@ int PipelineHandlerIPU3::configure(Camera *camera, CameraConfiguration *c)
configInfo.bdsOutputSize = config->imguConfig().bds;
configInfo.iif = config->imguConfig().iif;
+ /*
+ * \todo Find a better position where maxQueueRequests can be
+ * defined and fetched. Maybe in IPA Interface? Camera property?
+ * Not sure.
+ */
+ uint32_t maxQueueRequests = 16;
+ configInfo.maxQueueRequests = maxQueueRequests;
+ setMaxQueueRequests(maxQueueRequests);
+
ret = data->ipa_->configure(configInfo, &data->ipaControls_);
if (ret) {
LOG(IPU3, Error) << "Failed to configure IPA: "
diff --git a/src/libcamera/pipeline_handler.cpp b/src/libcamera/pipeline_handler.cpp
index 7ebd76ad..08ec28de 100644
--- a/src/libcamera/pipeline_handler.cpp
+++ b/src/libcamera/pipeline_handler.cpp
@@ -68,7 +68,8 @@ LOG_DEFINE_CATEGORY(Pipeline)
* respective factories.
*/
PipelineHandler::PipelineHandler(CameraManager *manager)
- : manager_(manager), lockOwner_(false)
+ : manager_(manager), maxQueueRequests_(0), requestsQueueCounter_(0),
+ lockOwner_(false)
{
}
@@ -312,6 +313,9 @@ void PipelineHandler::stop(Camera *camera)
/* Make sure no requests are pending. */
Camera::Private *data = camera->_d();
ASSERT(data->queuedRequests_.empty());
+
+ maxQueueRequests_ = 0;
+ requestsQueueCounter_ = 0;
}
/**
@@ -397,6 +401,9 @@ void PipelineHandler::doQueueRequest(Request *request)
Camera::Private *data = camera->_d();
data->queuedRequests_.push_back(request);
+ if (maxQueueRequests_)
+ requestsQueueCounter_++;
+
request->_d()->sequence_ = data->requestSequence_++;
if (request->_d()->cancelled_) {
@@ -424,6 +431,10 @@ void PipelineHandler::doQueueRequests()
if (!request->_d()->prepared_)
break;
+ if (maxQueueRequests_ &&
+ requestsQueueCounter_ >= maxQueueRequests_)
+ break;
+
doQueueRequest(request);
waitingRequests_.pop();
}
@@ -500,6 +511,9 @@ void PipelineHandler::completeRequest(Request *request)
ASSERT(!req->hasPendingBuffers());
data->queuedRequests_.pop_front();
camera->requestComplete(req);
+
+ if (maxQueueRequests_)
+ requestsQueueCounter_--;
}
}
@@ -616,6 +630,51 @@ void PipelineHandler::disconnect()
* constant for the whole lifetime of the pipeline handler.
*/
+/**
+ * \var PipelineHandler::maxQueueRequests_
+ * \brief Maximum number of in-flight requests that can be queued
+ *
+ * A hardware can handle a certain number of maximum requests at a given
+ * point. If such a constraint exists, set maxQueueRequests_ via
+ * \a setMaxQueueRequests() in the derived pipeline handler.
+ *
+ * The derived pipeline handler can choose not to define such constraint as
+ * well. In that case, the derived pipeline handler can avoid setting
+ * \a setMaxQueueReqeuests(), hence \a maxQueueRequests_ and
+ * \a requestsQueueCounter_ will be 0.
+ */
+
+/**
+ * \var PipelineHandler::requestsQueueCounter_
+ * \brief Number of requests queued to the underlying hardware
+ *
+ * If \a setMaxQueueRequests() is set by the derived pipeline handler,
+ * requestsQueueCounter_ reflects the number of requests queued
+ * to the underlying hardware by the pipeline handler.
+ */
+
+/**
+ * \fn PipelineHandler::maxQueueRequests()
+ * \brief Retrieve the maximum number of in-flight requests handled by the
+ * underlying hardware
+ * \return Number of requests that can be queued to underlying hardware
+ */
+
+/**
+ * \brief Sets the maximum number of requests that can be queued
+ * \param[in] maxRequests Maximum number of in-flight requests
+ *
+ * A hardware can handle a certain number of requests at a given point.
+ * This function sets the maximum number of in-flight requests that can
+ * be queued to the hardware by the pipeline handler. Each derived pipeline
+ * handler should set the maximum number of in-flight requests it can handle
+ * at a given point using this function, if at all such a constraint exists.
+ */
+void PipelineHandler::setMaxQueueRequests(uint32_t maxRequests)
+{
+ maxQueueRequests_ = maxRequests;
+}
+
/**
* \fn PipelineHandler::name()
* \brief Retrieve the pipeline handler name
--
2.31.1
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