[lkml]   [2000]   [Oct]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH] Re: PATCH: killing read_ahead[]

Rik van Riel wrote:
> On Wed, 25 Oct 2000, Jeff V. Merkey wrote:
> > I've reviewed the patch. It's affect seems minimal and will not
> > break NWFS as proposed -- it looks like, however, it will reduce
> > the performance slightly of EXT2/3 with iozone for read ahead
> > since the first section of the patch limits the read ahead
> > window size.
> Ummm, please read it again ;)
> The patch actually /increases/ the readahead size when
> we start to read a file from the beginning.

But only if the file is smaller than MIN_READAHEAD * 2, which would be
the case for small files (which would read the whole file anyway, which
is how the page cache behaves today anyway).

?* If we start reading from the beginning of the file, read in
that if the file is smaller then MIN_READAHEAD * 2 limiting ourselves to
result in one "too small" IO

(there's that fixed block size crap biting us in the ass again)

so in that case, just read the whole file.



> regards,
> Rik
> --
> "What you're running that piece of shit Gnome?!?!"
> -- Miguel de Icaza, UKUUG 2000
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
Please read the FAQ at

 \ /
  Last update: 2005-03-22 12:41    [W:0.091 / U:0.080 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site