From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Herrenschmidt To: Paul Mackerras , Dan Malek Cc: David Gibson , Subject: Re: CONFIG_PIN_TLB and telnet problems Date: Tue, 4 Jun 2002 14:37:08 +0200 Message-Id: <20020604123708.13854@smtp.adsl.oleane.com> In-Reply-To: <20020604122046.29082@mailhost.mipsys.com> References: <20020604122046.29082@mailhost.mipsys.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: > >To add to these comments, I can reproduce the problem as well on a >unix socket shared either between two processes, or read & written >by a single process. > >After doing various tests, the problem appears rarely and randomly >with half the RAM mapped with fixed TLBs, and very reproduceably >with all the RAM mapped this way. So it seems that reducing the >kernel pressure on TLBs, thus allowing userland TLBs to live much >longer, exhibit the problem. > >I tried adding a call to _tlbia (not the instruction but our tlbwe >based implementation) in set_context to make sure I only ever have >one userland context loaded in the TLB and this appear to kill the >problem (I'm currently running 2 offending test programs simultaneously >on the box and none failed yet after a few Gb transferred). Hrm... I added isync/sync (actually, the sync is probably too much) to set_context() in head_4xx.S in order to invalidate the shadow TLBs and it seems to work ! I'll test a few hours and let you know. Ben. ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/