Messages in this thread | | | Date | Mon, 24 Jul 2006 19:33:18 -0700 | From | Andrew Morton <> | Subject | Re: [RFC] ps command race fix |
| |
On Tue, 25 Jul 2006 11:08:35 +0900 KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote:
> > Then the seek and read and such semantics are nice and stable and > > simple. > > > yes... > I think snapshot at open() is okay.
We cannot do a single kmalloc() like cpuset does.
The kernel presently kind-of guarantees that a 32k kmalloc() will work, although the VM might have to do very large amounts of work to achieve it.
But 32k is only 8192 processes, so a snapshot will need multiple allocations and a list and trouble dropping and retaking tasklist_lock to allocate memory and keeping things stable while doing that. I suspect it'll end up ugly.
And it permits userspace to pin rather a lot of memory. - 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/
| |