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Commit 8f688f5b authored by Sandeep Patil's avatar Sandeep Patil Committed by android-build-merger
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Merge "meminfo: Add API to read pagemap for a vma within a process." 

am: 15a3a287

Change-Id: I3dba7766030dfebd5732f6586fdcbde7245385fd
parents e8b2ac49 15a3a287

libmeminfo/include/meminfo/pageacct.h

+12 −0
Original line number Diff line number Diff line
@@ -65,5 +65,17 @@ class PageAcct final { 
    ::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

libmeminfo/include/meminfo/procmeminfo.h

+7 −0
Original line number Diff line number Diff line
@@ -73,6 +73,13 @@ class ProcMemInfo final { 


    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:

libmeminfo/libmeminfo_test.cpp

+17 −0
Original line number Diff line number Diff line
@@ -121,6 +121,23 @@ TEST_F(ValidateProcMemInfo, TestSwapOffsets) { 
    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 {

libmeminfo/pageacct.cpp

+13 −0
Original line number Diff line number Diff line
@@ -138,5 +138,18 @@ int PageAcct::GetPageIdle(uint64_t pfn) const { 
    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

libmeminfo/procmeminfo.cpp

+27 −0
Original line number Diff line number Diff line
@@ -199,6 +199,33 @@ const std::vector<uint16_t>& ProcMemInfo::SwapOffsets() { 
    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