Re: [PATCH 0/5] make *_gate_vma accept mm_struct instead of task_struct II
From: Stephen Wilson <hidden>
Date: 2011-03-10 16:55:31
Also in:
linux-mm, linux-s390, linux-sh, lkml
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:quoted
On Tue, Mar 08, 2011 at 07:31:56PM -0500, Stephen Wilson wrote:quoted
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'ed by or reviewed by? Thanks for taking a look! -- steve