Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754796Ab0FNGeQ (ORCPT ); Mon, 14 Jun 2010 02:34:16 -0400 Received: from mail-yx0-f174.google.com ([209.85.213.174]:35089 "EHLO mail-yx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754589Ab0FNGeP (ORCPT ); Mon, 14 Jun 2010 02:34:15 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:date:message-id:subject:from:to:content-type; b=hgS39rM3C2eRqvGDXegDmAw75dtKTFaWXIAO2yb1zLAv4t22tHu9CjpChz+W8957vD dga0fm+LmFr4KaO6e4kLssj3TwG8UXAjSXaQXj/RqriJhGfOAA5D7WFOOZcjs8btcLNh djOfZMmtl6VqRABomPrh0OHO8IUtXpzrh3iVk= MIME-Version: 1.0 Date: Mon, 14 Jun 2010 00:34:12 -0600 Message-ID: Subject: 4K Pageable Stacks a MUST From: Jeffrey Merkey To: linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1037 Lines: 20 I have been running down bugs on the MDB Debugger on a 4 processor AMD Opteron System and have discovered that processors 1-X (other than 0) use a buttload of stack space when all the spinlock debgguging checks are turned on -- way too much memory and the systenter_past_esp panic shows up a lot. NetWare at one point instrumented the ability to page map an extra 4K of memory up to 16K (then release it when the stack shrunk back to a smaller usage footprint). I think for debugging and just general usage you should enable a 16K pagable limit with 4K stacks for debuggers and such or just to stop a lot of dump traps. It's getting to the point where 8K wont be enough when people need to debug spinlocks and rcu locks and other types of breakage. Would not be hard to instrument. Jeff -- 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/