Linux Manually Frees memory

Linux for a period of time, the memory is full, swap also began to use, because the Linux design read data will be cached in memory, so for frequent read applications can reduce IO consumption, but like me this is not SSD hard disk PC users, open the application feel a card, annoying all bored to death, Have to manually erase the data in memory (theoretically Linux will automatically free up memory).

In fact, a command is done:
Echo 3 >/proc/sys/vm/drop_caches

But before executing this command, please sync, write the cached data to the disk, or buffer to write the data, you have to cry ^ ^

3 is to release all memory, default is 0, cache any data

Linux Manually Frees memory