On Wed, 27 Sep 2006 23:49:49 -0700 Stephane Eranian <[EMAIL PROTECTED]> wrote:
> Andrew, > > On Wed, Sep 27, 2006 at 04:31:00PM -0700, Andrew Morton wrote: > > > > > > Here is the summary of the various point raised by your review and the > > > current > > > status. I am hoping to close all points by next release. > > > > > > ... > > > > > > [akpm]: use fget_light() in some place instead of fget() > > > - not sure understand when to use one versus the other > > > > > > > They are always interchangeable. fget_light() is simply an optimised, > > messier-to-use version. > > What are exactly the assumptions of fget_light()? Just the ones in the comment, really - it assumes that the caller has a single ref on the file. ie: we're within a system call which passed in an fd, or within a pagefault and this file* is current->mm->some_vma->vm_file. You _might_ get into trouble if using it against some file* which belongs to a different process, and if you don't already have a ref on that file*. But that's usually a bug anyway, unless the code is aware of and is exploiting the RCU management of these things. There are lots of example usages around the place. > > > > > > > > .. > > > > > > [akpm]: carta_random32() should be in another header file > > > - yes, I know. Should I create a specific header file? I don't think > > > random.h > > > is meant for this. > > > > I suppose so. Or just stick the declaration into kernel.h. > > > > I had a patch go past the other day which had a hand-rolled > > fast-but-not-very-good pseudo random number generator in it. I couldn't > > remember where I'd seen one, and now I can't remember what patch it was > > that needed it. Sigh. > > > > Anyway, a standalone patch which adds that function into lib/whatever.c > > would be nice. > > I will post a standalone patch for carta random. I can provide a standalone > header > file in include/linux/carta_random.h. Thanks. _______________________________________________ perfmon mailing list [email protected] http://www.hpl.hp.com/hosted/linux/mail-archives/perfmon/
