lkml.org 
[lkml]   [2001]   [Jul]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] copy_from_high_bh
On Sun, 8 Jul 2001, Linus Torvalds wrote:
> On Sun, 8 Jul 2001 markhe@veritas.com wrote:
> >
> > mm/highmem.c/copy_from_high_bh() blocks interrupts while copying "down"
> > to a bounce buffer, for writing.
> > This function is only ever called from create_bounce() (which cannot
> > be called from an interrupt context - it may block), and the kmap
> > 'KM_BOUNCE_WRITE' is only used in copy_from_high_bh().
>
> If so it's not just the interrupt disable that is unnecessary, the
> "kmap_atomic()" should also be just a plain "kmap()", I think.

That might eat through kmap()'s virtual window too quickly.

I did think about adding a test to see if the page was already mapped,
and falling back to kmap_atomic() if it isn't. That should give the best
of both worlds?

Mark

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 12:56    [W:0.107 / U:0.056 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site