Re: cat: FADV_DONTNEED option?

[Pádraig Brady]

On 28/10/15 11:47, Jacek Wielemborek wrote:
> Hello,
> 
> I noticed that after running "cat" on a huge file, I'm getting problems
> with system responsiveness, probably because my Linux kernel threw away
> all the cached files from the unallocated region of RAM. I read up and
> heard that fadvise(input_desc, 0, 0, FADV_DONTNEED) could solve my
> problem. I had this idea that perhaps it would make sense to add another
> command-line switch to cat that would trigger this fadvise(), adding a
> way to increase performance in some cases? I could write a patch if
> you're interested.

Already mentioned at 
http://www.gnu.org/software/coreutils/rejected_requests.html
  http://lists.gnu.org/archive/html/bug-coreutils/2013-10/msg00011.html
    See 'direct' ' and 'nocache' at http://www.gnu.org/software/coreutils/dd

thanks,
Pádraig.