Re: I/O blocked while dirty pages are being flushed

[Fredrik Tolf <fredrik@dolda2000.com>]

On Sun, 24 Mar 2013, Eric Wong wrote:
> Fredrik Tolf <fredrik@dolda2000.com> wrote:
>> It is worth noting, also, that this seems to be a situation
>> introduced somewhere between 2.6.26 and 2.6.32, because I started
>> noticing it when I upgraded from Debian 5.0 to 6.0. I've since tried
>> it on 3.2.0, 3.5.4 and 3.7.1, and it appears in every version.
>> However, I can't easily go back and bisect, because the new init
>> scripts don't support kernels older than 2.6.32, unfortunately.
>
> So try lowering these sysctls to 2.6.26 levels (or lower) and see if
> that helps.

Thanks for the tip, but since the page dirtying happens in fast bursts for 
me, rather than gradually over time, that just caused the same sizes of 
writes to happen more often instead, which only made it worse. :)

I'll continue investigating the stable-page route, instead, since that 
seems to be my exact problem.

--

Fredrik Tolf