lkml.org 
[lkml]   [2009]   [Sep]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [RFC][v6][PATCH 0/9] clone_with_pids() syscall
From
Date
On Fri, 2009-09-11 at 09:47 -0700, Sukadev Bhattiprolu wrote:
> | Also, if you're passing a struct, why not put nr_pids in there, and
> | replace clone_pid_struct with a simple array? That would give us
> |
> | struct clone_struct {
> | u64 flags;
> | u64 child_stack;
> | u32 child_tid;
> | u32 parent_tid;
> | u32 nr_pids;
> | u32 reserved1;
> | u64 reserved2;
> | };
> |
> | int clone2(struct clone_struct *cs, pid_t *pids);
>
> My only concern with this approach was the extra copy_from_user() in the
> common case (i.e when not using the extended features). I assume the
> overhead of copy_from_user() is small enough to be ignored ?

I would think so, esp for small structure, it would be a cache hot copy.
That is, for x86 I doubt it'll show up. No idea what hoops other arch
have to jump through to get copy_from_user() doing what it does.



\
 
 \ /
  Last update: 2009-09-11 19:03    [W:0.063 / U:39.000 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site