memory-size

I have a basic question about the policy followed by the memory system. Consider a core with private L1 and L2 caches. After L2 cache we have a bus on which the coherence traffic runs. Now, if a cache line for address(X) is evicted from the L2 cache, is it necessary to evict that address from the L1 cache ?? The reason for eviction can be that it helps in maintaining the invariant of the coherence protocol [if a line in l2 shows invalid this core does not contain this address]. There are three different designs and all are used. Exclusive: Data in the L1 cache is never in the L2 cache. Data in

I tried to make a simple pdo request to select all values of a table <?php public function query($query) { $this->stmt = $this->query($query); } ?> But when I call it like $db->query('SELECT * FROM teams'); $teams = $db->resultset(); print_r($teams); an error occured Fatal error: Allowed memory size of 536870912 bytes exhausted (tried to allocate 65484 bytes) in /var/www/flunky/functions/mysql.class.php on line 29 I tried to increase the memory size in php.ini and with ini_set('memory_limit', '512M'); , but it doesn´t work. Can anybody help me? Run this code before running a query $pdo-

I'm typing a shell script to find out the total physical memory in some RHEL linux boxes. First of all I want to stress that I'm interested in the total physical memory recognized by kernel, not just the available memory . Therefore, please, avoid answers suggesting to read /proc/meminfo or to use the free , top or sar commands -- In all these cases, their " total memory " values mean " available memory " ones. The first thought was to read the boot kernel messages: Memory: 61861540k/63438844k available (2577k kernel code, 1042516k reserved, 1305k data, 212k init) But in some linux boxes, due