Function freeMemoryGetNotCountedMemory

app/redis-6.2.6/src/evict.c:330–348

We don't want to count AOF buffers and slaves output buffers as * used memory: the eviction should use mostly data size. This function * returns the sum of AOF and slaves buffer. */

 * used memory: the eviction should use mostly data size. This function
 * returns the sum of AOF and slaves buffer. */
size_t freeMemoryGetNotCountedMemory(void) {
    size_t overhead = 0;
    int slaves = listLength(server.slaves);

    if (slaves) {
        listIter li;
        listNode *ln;

        listRewind(server.slaves,&li);
        while((ln = listNext(&li))) {
            client *slave = listNodeValue(ln);
            overhead += getClientOutputBufferMemoryUsage(slave);
        }
    }
    if (server.aof_state != AOF_OFF) {
        overhead += sdsalloc(server.aof_buf)+aofRewriteBufferSize();
    }
    return overhead;
}

/* Get the memory status from the point of view of the maxmemory directive:
 * if the memory used is under the maxmemory setting then C_OK is returned.