On Tue, Jul 19, 2022 at 11:04:36PM -0700, Christoph Hellwig wrote: > On Wed, Jul 20, 2022 at 06:02:32AM +0000, CGEL wrote: > > For example, some systems will create a lot of pagecache when boot up > > while reading bzImage, ramdisk, docker images etc. Most of this pagecache > > is useless after boot up. It may has a longterm negative effects for the > > workload when trigger page reclaim. It is especially harmful when trigger > > direct_reclaim or we need allocate pages in atomic context. So users may > > chose to drop_caches after boot up. > > It is purely a debug interface. If you want to drop specific page cache > that needs to be done through madvise. It's not easy for users to use madvise in complex system, it takes cost. Since drop_caches is not forbidden, and users may want simply use it in the scene above mail described.
