ViewPager обновить

Как обновить ViewPager. Он входит в другой ViewPager. Получается так что он обновляет данные только после первого перелистывания. А как сделать уже обновленные данные до этого

public class Fragment_adapter_history extends Fragment {
            private SectionsPagerAdapter mSectionsPagerAdapter;
            private ViewPager mViewPager;
            static final String TAG = "myLogs";
            @Override
            public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
            View view = inflater.inflate(R.layout.fragment_history_adapter, container, false);
            mSectionsPagerAdapter = new SectionsPagerAdapter(getChildFragmentManager());
            mViewPager = (ViewPager) view.findViewById(R.id.vpPager);
            mViewPager.setAdapter(mSectionsPagerAdapter);
            mViewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
                @Override
                public void onPageSelected(int position) {
                    Log.d(TAG, "onPageSelected, position = " + position);
                    mSectionsPagerAdapter.notifyDataSetChanged();
                }
                @Override
                public void onPageScrolled(int position, float positionOffset,
                                           int positionOffsetPixels) {
                }
                @Override
                public void onPageScrollStateChanged(int state) {
                }
            });
            return view;
        }
        public void generate()
        {
            mSectionsPagerAdapter.notifyDataSetChanged();
        }
     public class SectionsPagerAdapter extends FragmentStatePagerAdapter {
            public int getItemPosition (Object object) { return POSITION_NONE; }
            public SectionsPagerAdapter(FragmentManager fm) {
                super(fm);
            }
            @Override
            public Fragment getItem(int position) {
                switch (position) {
                    case 0:
                        FragmentTransaction fragmentTransaction;
                        fragmentTransaction = getActivity().getSupportFragmentManager().beginTransaction();
                        Fragment_history fragment_history = new Fragment_history();
                        fragmentTransaction.commit();
                        return fragment_history;
                    case 1:
                        FragmentTransaction fragmentTransaction2;
                        fragmentTransaction2 = getActivity().getSupportFragmentManager().beginTransaction();
                        Fragment_izbranoe fragment_izbranoe = new Fragment_izbranoe();
                        fragmentTransaction2.commit();
                        return fragment_izbranoe;
                    default:
                        return null;
                }
            }

            @Override
            public int getCount() {
                // Show 3 total pages.
                return 2;
            }
            @Override
            public CharSequence getPageTitle(int position) {
                switch (position) {
                    case 0:
                        return "История";
                    case 1:
                        return "Избранное";
                }
                return null;
            }
        }
    }