From: Wei Wang <wvw@google.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: "Wei Wang" <wei.vince.wang@gmail.com>,
gregkh@linuxfoundation.org, "Todd Poynor" <toddpoynor@google.com>,
"Dan Williams" <dan.j.williams@intel.com>,
"Michal Hocko" <mhocko@suse.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
"Jan Kara" <jack@suse.cz>, "Jérôme Glisse" <jglisse@redhat.com>,
"Hugh Dickins" <hughd@google.com>,
"Matthew Wilcox" <willy@infradead.org>,
"Ingo Molnar" <mingo@kernel.org>,
"Sherry Cheung" <SCheung@nvidia.com>,
"Oliver O'Halloran" <oohall@gmail.com>,
"Andrey Ryabinin" <aryabinin@virtuozzo.com>,
"Huang Ying" <ying.huang@intel.com>,
"Dennis Zhou" <dennisz@fb.com>,
"Pavel Tatashin" <pasha.tatashin@oracle.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm: add config for readahead window
Date: Fri, 16 Mar 2018 22:13:19 +0000 [thread overview]
Message-ID: <CAGXk5yoL=NuW1d1VHD9_CXi3kg0gmKeWFubNC7Ro053yDnR9vA@mail.gmail.com> (raw)
In-Reply-To: <20180316145942.9e2d353ed10041fbac42e5a3@linux-foundation.org>
On Fri, Mar 16, 2018 at 2:59 PM Andrew Morton <akpm@linux-foundation.org>
wrote:
> On Fri, 16 Mar 2018 21:51:48 +0000 Wei Wang <wei.vince.wang@gmail.com>
wrote:
> > On Fri, Mar 16, 2018, 14:33 Andrew Morton <akpm@linux-foundation.org>
wrote:
> >
> > > On Fri, 16 Mar 2018 11:25:08 -0700 Wei Wang <wvw@google.com> wrote:
> > >
> > > > Change VM_MAX_READAHEAD value from the default 128KB to a
configurable
> > > > value. This will allow the readahead window to grow to a maximum
size
> > > > bigger than 128KB during boot, which could benefit to sequential
read
> > > > throughput and thus boot performance.
> > >
> > > You can presently run ioctl(BLKRASET) against the block device?
> > >
> >
> > Yeah we are doing tuning in userland after init. But this is something
we
> > thought could help in very early stage.
> >
> "thought" and "could" are rather weak! Some impressive performance
> numbers for real-world setups would help such a patch along.
~90ms savings from an Android device compared to setting the window later
in userland.
I was using 'week' words as I agree with Linus's point - it is all about
the storage, so the savings are not universal indeed.
prev parent reply other threads:[~2018-03-16 22:13 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-16 18:25 Wei Wang
2018-03-16 18:49 ` Wei Wang
2018-03-16 20:53 ` Greg KH
2018-03-19 2:36 ` Huang, Ying
2018-03-19 3:15 ` Wei Wang
2018-03-20 20:17 ` Jan Kara
2018-03-16 20:56 ` Kirill A. Shutemov
2018-03-16 21:26 ` Linus Torvalds
2018-03-16 21:33 ` Andrew Morton
2018-03-16 21:51 ` Wei Wang
2018-03-16 21:59 ` Andrew Morton
2018-03-16 22:13 ` Wei Wang [this message]
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