From: Linus Torvalds Date: Fri, 24 Oct 2008 17:53:20 GMT Subject: Re: git performance Message-ID: In-Reply-To: <20081024142947.GB11568@coredump.intra.peff.net> On Fri, 24 Oct 2008, Jeff King wrote: > > Side note: on Linux, it is much easier to clear the cache via > > echo 1 >/proc/sys/vm/drop_caches Use "echo 3" instead of "1". It's actually a bitmask, with bit 0 being "data" (pagecache) and bit 1 being "metadata" (inodes and directory caches). And since git (or any SCM) is very metadata-intensive, you really should make sure to drop metadata too, otherwise your caches won't be really very cold at all. (But it obviously depends on the operation you're testing - some are more about the inodes and directories, others are about file data access). Linus