On Sat, 9 Dec 2000, Alexander Viro wrote:
> On Sat, 9 Dec 2000, Andries Brouwer wrote:
>
> > On Sat, Dec 09, 2000 at 05:40:47AM -0500, Alexander Viro wrote:
> >
> > > > @@ -1210,7 +1204,6 @@
> > > [breada()]
> > > Umm... why do we keep it, in the first place? AFAICS the only
> > > in-tree user is hpfs_map_sector() and it doesn't look like we really
> > > need it there. OTOH, trimming the buffer.c down is definitely nice.
> > > Mikulas?
> >
> > Throw it out. The number of users has diminished over time.
> > Recently isofs stopped using breada.
> > The hpfs use was broken, I fixed it a bit some time ago, but
> > there is nothing against throwing it out altogether, I think.
>
> I've looked at the use of hpfs_map_sector() (and hpfs_map_4sectors() - sorry)
> and it looks like we would be better off doing getblk() on affected sectors
> and ll_rw_block() on the whole bunch - we end up calling breada() for
> increasing block numbers with decreasing readahead window anyway.
>
> So it probably should go - it gives no real win. Mikulas has the final
> word here - he is the HPFS maintainer, so...
I did a test. I disabled readahead except for reading all 4 buffers in
map_4sectors.
I observed 14% slowdown on walking directories with find and 4% slowdown
on grepping one my working directory (10M, 281 files).
If you can't make it otherwise you can rip readahead out. If there is a
possibility to keep it, it would be better.
Mikulas
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This archive was generated by hypermail 2b29 : Fri Dec 15 2000 - 21:00:18 EST