Re: [PATCH 0/5] make *_gate_vma accept mm_struct instead of task_struct II
From: "H. Peter Anvin" <hpa@zytor.com>
Date: 2011-03-10 17:23:29
Also in:
linux-mm, linux-s390
Sorry... I confused them too. It's TS_COMPAT which is problematic. -- Sent from my mobile phone. Please pardon any lack of formatting. Stephen Wilson [off-list ref] wrote: On Thu, Mar 10, 2011 at 08:38:09AM -0800, Andi Kleen wrote: > On Thu, Mar 10, 2011 at 08:00:32AM -0800, Andi Kleen wrote: > > On Tue, Mar 08, 2011 at 07:31:56PM -0500, Stephen Wilson wrote: > > > The only architecture this change impacts in any significant way is x86_64. > > > The principle change on that architecture is to mirror TIF_IA32 via > > > a new flag in mm_context_t. > > > > The problem is -- you're adding a likely cache miss on mm_struct for > > every 32bit compat syscall now, even if they don't need mm_struct > > currently (and a lot of them do not) Unless there's a very good > > justification to make up for this performance issue elsewhere > > (including numbers) this seems like a bad idea. > > Hmm I see you're only setting it on exec time actually on rereading > the patches. I thought you were changing TS_COMPAT which is in > the syscall path. > > Never mind. I have no problems with doing such a change on exec > time. OK. Great! Does this mean I have your ACK'e! d by or reviewed by? Thanks for taking a look! -- steve