meminfo: handle multiple buffer references in dmabufinfo
Change the dmabufinfo library to handle multiple references to the same
buffer across PIDs by doing these changes:
- Add function AppendDmaBufInfo: appends the information for a specific
PID to an existing DmaBuffer vector
- Change the way fd/map references to a buffer belonging to a PID are
stored in DmaBuffer from vector<pid_t> to unorderedmap<pid_t, int>
- When parsing proc/%pid/{maps|fds}, look up the buffer by inode and
update the data if found
Test: builds
Bug: 63860998
Change-Id: If22feea772f182086ae3446b46d626a750674b1f
Signed-off-by: Erick Reyes <erickreyes@google.com>
diff --git a/libmeminfo/libdmabufinfo/dmabufinfo.cpp b/libmeminfo/libdmabufinfo/dmabufinfo.cpp
index 41ecc51..b4ad667 100644
--- a/libmeminfo/libdmabufinfo/dmabufinfo.cpp
+++ b/libmeminfo/libdmabufinfo/dmabufinfo.cpp
@@ -119,9 +119,23 @@
return false;
}
- DmaBuffer& buf =
+ uint64_t inode = sb.st_ino;
+ auto buf = std::find_if(dmabufs->begin(), dmabufs->end(),
+ [&inode](const DmaBuffer& dbuf) { return dbuf.inode() == inode; });
+ if (buf != dmabufs->end()) {
+ if (buf->name() == "" || buf->name() == "<unknown>")
+ buf->SetName(name);
+ if (buf->exporter() == "" || buf->exporter() == "<unknown>")
+ buf->SetExporter(exporter);
+ if (buf->count() == 0)
+ buf->SetCount(count);
+ buf->AddFdRef(pid);
+ return true;
+ }
+
+ DmaBuffer& db =
dmabufs->emplace_back(sb.st_ino, sb.st_blocks * 512, count, exporter, name);
- buf.AddFdRef(pid);
+ db.AddFdRef(pid);
}
return true;
@@ -225,6 +239,10 @@
bool ReadDmaBufInfo(pid_t pid, std::vector<DmaBuffer>* dmabufs) {
dmabufs->clear();
+ return AppendDmaBufInfo(pid, dmabufs);
+}
+
+bool AppendDmaBufInfo(pid_t pid, std::vector<DmaBuffer>* dmabufs) {
if (!ReadDmaBufFdRefs(pid, dmabufs)) {
LOG(ERROR) << "Failed to read dmabuf fd references";
return false;
diff --git a/libmeminfo/libdmabufinfo/dmabufinfo_test.cpp b/libmeminfo/libdmabufinfo/dmabufinfo_test.cpp
index aa5f16c..95aa2c7 100644
--- a/libmeminfo/libdmabufinfo/dmabufinfo_test.cpp
+++ b/libmeminfo/libdmabufinfo/dmabufinfo_test.cpp
@@ -21,6 +21,7 @@
#include <string>
#include <vector>
+#include <unordered_map>
#include <android-base/file.h>
#include <android-base/logging.h>
@@ -61,18 +62,16 @@
#define EXPECT_PID_IN_FDREFS(_bufptr, _pid, _expect) \
do { \
- const std::vector<pid_t>& _fdrefs = _bufptr->fdrefs(); \
- auto _ref = std::find_if(_fdrefs.begin(), _fdrefs.end(), \
- [&](const pid_t& p) { return p == _pid; }); \
- EXPECT_EQ((_ref == _fdrefs.end()), _expect); \
+ const std::unordered_map<pid_t, int>& _fdrefs = _bufptr->fdrefs(); \
+ auto _ref = _fdrefs.find(_pid); \
+ EXPECT_EQ((_ref != _fdrefs.end()), _expect); \
} while (0)
#define EXPECT_PID_IN_MAPREFS(_bufptr, _pid, _expect) \
do { \
- const std::vector<pid_t>& _maprefs = _bufptr->maprefs(); \
- auto _ref = std::find_if(_maprefs.begin(), _maprefs.end(), \
- [&](const pid_t& p) { return p == _pid; }); \
- EXPECT_EQ((_ref == _maprefs.end()), _expect); \
+ const std::unordered_map<pid_t, int>& _maprefs = _bufptr->maprefs(); \
+ auto _ref = _maprefs.find(_pid); \
+ EXPECT_EQ((_ref != _maprefs.end()), _expect); \
} while (0)
TEST(DmaBufInfoParser, TestReadDmaBufInfo) {
diff --git a/libmeminfo/libdmabufinfo/include/dmabufinfo/dmabufinfo.h b/libmeminfo/libdmabufinfo/include/dmabufinfo/dmabufinfo.h
index 29ce4d0..74eff3c 100644
--- a/libmeminfo/libdmabufinfo/include/dmabufinfo/dmabufinfo.h
+++ b/libmeminfo/libdmabufinfo/include/dmabufinfo/dmabufinfo.h
@@ -21,6 +21,7 @@
#include <string>
#include <vector>
+#include <unordered_map>
namespace android {
namespace dmabufinfo {
@@ -33,20 +34,27 @@
~DmaBuffer() = default;
// Adds one file descriptor reference for the given pid
- void AddFdRef(pid_t pid) { fdrefs_.emplace_back(pid); }
+ void AddFdRef(pid_t pid) {
+ AddRefToPidMap(pid, &fdrefs_);
+ }
// Adds one map reference for the given pid
- void AddMapRef(pid_t pid) { maprefs_.emplace_back(pid); }
+ void AddMapRef(pid_t pid) {
+ AddRefToPidMap(pid, &maprefs_);
+ }
// Getters for each property
uint64_t size() { return size_; }
- const std::vector<pid_t>& fdrefs() const { return fdrefs_; }
- const std::vector<pid_t>& maprefs() const { return maprefs_; }
+ const std::unordered_map<pid_t, int>& fdrefs() const { return fdrefs_; }
+ const std::unordered_map<pid_t, int>& maprefs() const { return maprefs_; }
ino_t inode() const { return inode_; }
uint64_t total_refs() const { return fdrefs_.size() + maprefs_.size(); }
uint64_t count() const { return count_; };
const std::string& name() const { return name_; }
const std::string& exporter() const { return exporter_; }
+ void SetName(const std::string& name) { name_ = name; }
+ void SetExporter(const std::string& exporter) { exporter_ = exporter; }
+ void SetCount(uint64_t count) { count_ = count; }
private:
ino_t inode_;
@@ -54,20 +62,37 @@
uint64_t count_;
std::string exporter_;
std::string name_;
- std::vector<pid_t> fdrefs_;
- std::vector<pid_t> maprefs_;
+ std::unordered_map<pid_t, int> fdrefs_;
+ std::unordered_map<pid_t, int> maprefs_;
+ void AddRefToPidMap(pid_t pid, std::unordered_map<pid_t, int>* map) {
+ // The first time we find a ref, we set the ref count to 1
+ // otherwise, increment the existing ref count
+ auto [it, inserted] = map->insert(std::make_pair(pid, 1));
+ if (!inserted)
+ it->second++;
+ }
};
// Read and return current dma buf objects from
// DEBUGFS/dma_buf/bufinfo. The references to each dma buffer are not
// populated here and will return an empty vector.
+//
// Returns false if something went wrong with the function, true otherwise.
bool ReadDmaBufInfo(std::vector<DmaBuffer>* dmabufs,
const std::string& path = "/sys/kernel/debug/dma_buf/bufinfo");
+
// Read and return dmabuf objects for a given process without the help
// of DEBUGFS
+//
+// Returns false if something went wrong with the function, true otherwise.
bool ReadDmaBufInfo(pid_t pid, std::vector<DmaBuffer>* dmabufs);
+// Append dmabuf objects for a given process without the help
+// of DEBUGFS to an existing vector
+//
+// Returns false if something went wrong with the function, true otherwise.
+bool AppendDmaBufInfo(pid_t pid, std::vector<DmaBuffer>* dmabufs);
+
} // namespace dmabufinfo
} // namespace android