From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id 3A739DE07C for ; Fri, 26 Oct 2007 11:51:34 +1000 (EST) Subject: Re: Apparent kernel bug with GDB on ppc405 From: Benjamin Herrenschmidt To: Daniel Jacobowitz In-Reply-To: <20071024224130.GA30819@caradoc.them.org> References: <20071024194640.GB19691@waste.org> <20071024204215.GC19691@waste.org> <20071024215421.GF19691@waste.org> <20071024223250.GI19691@waste.org> <20071024224130.GA30819@caradoc.them.org> Content-Type: text/plain Date: Fri, 26 Oct 2007 11:51:22 +1000 Message-Id: <1193363482.7018.41.camel@pasglop> Mime-Version: 1.0 Cc: gdb@sourceware.org, linuxppc-embedded@ozlabs.org, Matt Mackall Reply-To: benh@kernel.crashing.org List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 2007-10-24 at 18:41 -0400, Daniel Jacobowitz wrote: > On Wed, Oct 24, 2007 at 05:32:50PM -0500, Matt Mackall wrote: > > Not completely implausible, but a) why isn't this seen on basically > > every machine with software TLB? b) why does -local- GDB, which is > > presumably doing much less work than gdbserver + network stack, not fail? > > You said it yourself. Local gdb does more work -> blows through more > TLB entries. > > I can't answer you about the other half, but I'm pretty sure TLB > invalidation is already supposed to be happening... somewhere. Yes. do_wp_page() -> ptep_clear_flush() -> flush_tlb_page() Ben.