Merge "meminfo: Add API to read pagemap for a vma within a process." am: 15a3a287f2
am: 8f688f5b2d
Change-Id: I4af15538624a777472022ac7a941a69a55d21f7e
diff --git a/libmeminfo/include/meminfo/pageacct.h b/libmeminfo/include/meminfo/pageacct.h
index 8ddaef2..8483d84 100644
--- a/libmeminfo/include/meminfo/pageacct.h
+++ b/libmeminfo/include/meminfo/pageacct.h
@@ -65,5 +65,17 @@
::android::base::unique_fd pageidle_fd_;
};
+// Returns if the page present bit is set in the value
+// passed in.
+bool page_present(uint64_t pagemap_val);
+
+// Returns if the page swapped bit is set in the value
+// passed in.
+bool page_swapped(uint64_t pagemap_val);
+
+// Returns the page frame number (physical page) from
+// pagemap value
+uint64_t page_pfn(uint64_t pagemap_val);
+
} // namespace meminfo
} // namespace android
diff --git a/libmeminfo/include/meminfo/procmeminfo.h b/libmeminfo/include/meminfo/procmeminfo.h
index 0b66074..95e5053 100644
--- a/libmeminfo/include/meminfo/procmeminfo.h
+++ b/libmeminfo/include/meminfo/procmeminfo.h
@@ -73,6 +73,13 @@
const std::vector<uint16_t>& SwapOffsets();
+ // Reads /proc/<pid>/pagemap for this process for each page within
+ // the 'vma' and stores that in 'pagemap'. It is assumed that the 'vma'
+ // is obtained by calling Maps() or 'ForEachVma' for the same object. No special checks
+ // are made to see if 'vma' is *valid*.
+ // Returns false if anything goes wrong, 'true' otherwise.
+ bool PageMap(const Vma& vma, std::vector<uint64_t>* pagemap);
+
~ProcMemInfo() = default;
private:
diff --git a/libmeminfo/libmeminfo_test.cpp b/libmeminfo/libmeminfo_test.cpp
index 7d85dd2..0e0212f 100644
--- a/libmeminfo/libmeminfo_test.cpp
+++ b/libmeminfo/libmeminfo_test.cpp
@@ -121,6 +121,23 @@
EXPECT_EQ(proc_usage.swap / getpagesize(), swap_offsets.size());
}
+TEST_F(ValidateProcMemInfo, TestPageMap) {
+ std::vector<uint64_t> pagemap;
+
+ auto vma_callback = [&](const Vma& vma) {
+ uint64_t* pmap_out;
+ size_t len;
+ ASSERT_EQ(0, pm_process_pagemap_range(proc, vma.start, vma.end, &pmap_out, &len));
+ ASSERT_TRUE(proc_mem->PageMap(vma, &pagemap));
+
+ EXPECT_EQ(len, ((vma.end - vma.start) / getpagesize()));
+ for (size_t i = 0; i < len; i++) {
+ EXPECT_EQ(pmap_out[i], pagemap[i]);
+ }
+ };
+ ASSERT_TRUE(proc_mem->ForEachVma(vma_callback));
+}
+
class ValidateProcMemInfoWss : public ::testing::Test {
protected:
void SetUp() override {
diff --git a/libmeminfo/pageacct.cpp b/libmeminfo/pageacct.cpp
index 887a74d..0a26c08 100644
--- a/libmeminfo/pageacct.cpp
+++ b/libmeminfo/pageacct.cpp
@@ -138,5 +138,18 @@
return !!(idle_bits & (1ULL << (pfn % 64)));
}
+// Public methods
+bool page_present(uint64_t pagemap_val) {
+ return PAGE_PRESENT(pagemap_val);
+}
+
+bool page_swapped(uint64_t pagemap_val) {
+ return PAGE_SWAPPED(pagemap_val);
+}
+
+uint64_t page_pfn(uint64_t pagemap_val) {
+ return PAGE_PFN(pagemap_val);
+}
+
} // namespace meminfo
} // namespace android
diff --git a/libmeminfo/procmeminfo.cpp b/libmeminfo/procmeminfo.cpp
index d6332a3..1df03b2 100644
--- a/libmeminfo/procmeminfo.cpp
+++ b/libmeminfo/procmeminfo.cpp
@@ -199,6 +199,33 @@
return swap_offsets_;
}
+bool ProcMemInfo::PageMap(const Vma& vma, std::vector<uint64_t>* pagemap) {
+ pagemap->clear();
+ std::string pagemap_file = ::android::base::StringPrintf("/proc/%d/pagemap", pid_);
+ ::android::base::unique_fd pagemap_fd(
+ TEMP_FAILURE_RETRY(open(pagemap_file.c_str(), O_RDONLY | O_CLOEXEC)));
+ if (pagemap_fd < 0) {
+ PLOG(ERROR) << "Failed to open " << pagemap_file;
+ return false;
+ }
+
+ uint64_t nr_pages = (vma.end - vma.start) / getpagesize();
+ pagemap->reserve(nr_pages);
+
+ uint64_t idx = vma.start / getpagesize();
+ uint64_t last = idx + nr_pages;
+ uint64_t val;
+ for (; idx < last; idx++) {
+ if (pread64(pagemap_fd, &val, sizeof(uint64_t), idx * sizeof(uint64_t)) < 0) {
+ PLOG(ERROR) << "Failed to read page frames from page map for pid: " << pid_;
+ return false;
+ }
+ pagemap->emplace_back(val);
+ }
+
+ return true;
+}
+
bool ProcMemInfo::ReadMaps(bool get_wss) {
// Each object reads /proc/<pid>/maps only once. This is done to make sure programs that are
// running for the lifetime of the system can recycle the objects and don't have to