Re: Updated disc cache

In message <20150403135237.GD18724@kyllikki.org>
Vincent Sanders <vince@netsurf-browser.org> wrote:

> On Fri, Apr 03, 2015 at 02:39:05PM +0100, cj wrote:
>> In article <mpro.nm8dx001qojsl00l7.pittdj@pittdj.co.uk>,
>> David Pitt <pittdj@pittdj.co.uk> wrote:
>> > Hmm! My Iyonix did over three time better than that, and there was
>> > no "too slow" message. My test piece was http://www.dailymail.co.uk
>> > because that is a particularly heavy duty site.
>>
>> OK. A lot of random browsing around that site led to:
>>
>> (5743.130000) content/llcache.c llcache_finalise 3352: Backing store
>> average bandwidth 531777 bytes/second
>>
>> which is over 5 times faster. However, I thought we would be talking
>> drive speed, which shouldn't be affected by the download speed of any
>> particular site, or am I completely up the wrong alley?
>
> That value is *purely* the total amount *written* to disc divided by
> how long the write operations took. The write time includes all
> directory creation/seek operations etc. rather than just the raw disc
> write performance.
>
> Anything above a megabit a second (125000 bytes/second) will not
> trigger the warning about low write speed. I set it there because
> below that value the overheads of disc caching exceed the benefit of
> simply fetching data from the network.
>
I have some results from my Pi B (system details below):

1. Accessing Steve's Digicams Reviews (a content-heavy page)
http://www.steves-digicams.com/camera-reviews/
content/llcache.c llcache_finalise 3352: Backing store average
bandwidth 6426 bytes/second;

2. Accessing Digital Photography Review
http://www.dpreview.com/reviews
content/llcache.c llcache_finalise 3352: Backing store average
bandwidth 449 bytes/second.

Pretty dire, and unsurprisingly the 'inadequate bandwidth' warning was
triggered in both cases. NetSurf is running on my system SD card, a
Kingston 4GB class 10 item. Other system details: NS 3.4 [Dev CI
#2696], RasPi B @ 900MHz, RO 5.21 [RC12, 12-Jan-15].

--
George