lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Fri, 14 Feb 2014 08:43:05 +0100
From:	Jan Kara <>
To:	Linus Torvalds <>
Cc:	Nishanth Aravamudan <>,
	David Rientjes <>,
	Raghavendra K T <>,
	Andrew Morton <>,
	Fengguang Wu <>,
	David Cohen <>,
	Al Viro <>,
	Damien Ramonda <>,
	Jan Kara <>, linux-mm <>,
	Linux Kernel Mailing List <>
Subject: Re: [RFC PATCH V5] mm readahead: Fix readahead fail for no local
 memory and limit readahead pages

On Thu 13-02-14 16:37:53, Linus Torvalds wrote:
> Is this whole thread still just for the crazy and pointless
> "max_sane_readahead()"?
> Or is there some *real* reason we should care?
> Because if it really is just for max_sane_readahead(), then for the
> love of God, let us just do this
>  unsigned long max_sane_readahead(unsigned long nr)
>  {
>         return min(nr, 128);
>  }
> and bury this whole idiotic thread.
  max_sane_readahead() is also used for limiting amount of readahead for
[fm]advice(2) WILLNEED and that is used e.g. by a dynamic linker to preload
shared libraries into memory. So I'm convinced this usecase *will* notice
the change - effectively we limit preloading of shared libraries to the
first 512KB in the file but libraries get accessed in a rather random manner.

Maybe limits for WILLNEED and for standard readahead should be different.
It makes sence to me and people seem to keep forgetting that
max_sane_readahead() limits also WILLNEED preloading.


> On Thu, Feb 13, 2014 at 4:14 PM, Nishanth Aravamudan
> <> wrote:
> >
> > I'm working on this latter bit now. I tried to mirror ia64, but it looks
> > like they have CONFIG_USER_PERCPU_NUMA_NODE_ID, which powerpc doesn't.
> > CONFIG_HAVE_MEMORYLESS_NODES should be tied together in Kconfig?
> >
> > I'll keep working, but would appreciate any further insight.
> >
> > -Nish
> >
Jan Kara <>
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

Powered by blists - more mailing lists