Hi. I can choose one of two different related things in userland, and one takes more physical memory than the other but runs faster. Looking at the number of free pages in the system doesn't really tell me whether memory is "tight" or not. There could be plenty of pages being used for caches, and at the first sign of memory pressure, those caches may shrink. The best way I can think of to know whether memory is really tight is to measure how often shrink_zone is getting called. (I'm looking at a 2.6.0-test11 kernel.) I can add some light instrumentation to track the rate at which shrink_zone gets called and a system call to make that rate visible to userland. Is there an existing way already in place or a better way to know when memory is tight? -- --Ed L Cashin | PGP public key: ecashin@uga.edu | http://noserose.net/e/pgp/ -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
