lists.openwall.net   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  linux-hardening  linux-cve-announce  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:	Wed, 7 Apr 2010 16:13:51 +0800
From:	Wu Fengguang <fengguang.wu@...el.com>
To:	Minchan Kim <minchan.kim@...il.com>
Cc:	Taras Glek <tglek@...illa.com>,
	Johannes Weiner <hannes@...xchg.org>,
	"linux-mm@...ck.org" <linux-mm@...ck.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: Downsides to madvise/fadvise(willneed) for application startup

Minchan,

> A few month ago, I saw your patch about enhancing readahead.
> At that time, many guys tested several size of USB and SSD which are
> consist of nand device.
> The result is good if we does readahead untile some crossover point.
> So I think we need readahead about file I/O in non-rotation device, too.
> 
> But startup latency is important than file I/O performance in some machine.
> With analysis at that time, code readahead of application affected slow startup.
> In addition, during bootup, cache hit ratio was very small.
> 
> So I hoped we can disable readahead just only code section(ie, roughly
> exec vma's filemap fault). :)
> 
> I don't want you to solve this problem right now.
> Just let you understand embedded system's some problem
> for enhancing readahead in future.  :)

Yeah, I've never heard of such a demand, definitely good to know it!

Thanks,
Fengguang
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ