FLAME_GRAPH_NENTRIES
fge = &fg->fge[fg->windex % FLAME_GRAPH_NENTRIES];
FLAME_GRAPH_NENTRIES);
fge = kmalloc(sizeof(*fge) * FLAME_GRAPH_NENTRIES,
fg->nentries = FLAME_GRAPH_NENTRIES;
sizeof(struct flame_graph_entry) * FLAME_GRAPH_NENTRIES;