frag_get_pending_idx
frag_get_pending_idx(&shinfo->frags[0]) ==
pending_idx = frag_get_pending_idx(&shinfo->frags[i]);
pending_idx = frag_get_pending_idx(&shinfo->frags[j]);
pending_idx = frag_get_pending_idx(&first_shinfo->frags[j]);
pending_idx = frag_get_pending_idx(frag);