Re: [PATCH] mm : sync ra->ra_pages with bdi->ra_pages

[Zhaoyang Huang]

On Sat, Aug 15, 2020 at 12:15 PM Andrew Morton
<akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> On Fri, 14 Aug 2020 13:10:34 -0700 Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> > On Fri, 14 Aug 2020 17:03:44 +0800 Zhaoyang Huang <huangzhaoyang@xxxxxxxxx> wrote:
> >
> > > Some system(like android) will turbo read during startup via expanding the
> > > readahead window and then set it back to normal(128kb as usual). However, some
> > > files in the system process context will keep to be opened since it is opened
> > > up and has no chance to sync with the updated value as it is almost impossible
> > > to change the files attached to the inode(processes are unaware of these things)
> >
> > How about making VM_READAHEAD_PAGES a variable?
>
> Or make it settable in Kconfig?
I don't think so. The scenario I gave before is a dynamic process,
can't be solved via menuconfig thing.