From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 12 Sep 2002 07:51:46 -0700 From: Tom Rini To: Benjamin Herrenschmidt Cc: Todd Poynor , linuxppc-dev Subject: Re: consistent_free re-revisited Message-ID: <20020912145146.GD13840@opus.bloom.county> References: <20020912142945.GC13840@opus.bloom.county> <20020912072315.5346@192.168.4.1> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20020912072315.5346@192.168.4.1> Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: On Thu, Sep 12, 2002 at 09:23:15AM +0200, Benjamin Herrenschmidt wrote: > >> That's the least of our worries - the current consistent_alloc() is > >> badly broken. It breaks the DMA-mapping.txt rules, because it can't > >> safely be called from interrupt context. I think we need generic > >> changes (gfp masks to various functions) to fix this sanely. > > > >IIRC, to fix the interrupt context bit, we need something like the > >following, which was Paul's idea, and he said he would talk to Dave M. > >about it. Did anything ever happen there? > > I tend to hate anything that relies on in_interrupt() as they > are other contexts that will have in_interrupt() cleared but still > have the same limitations. Typically, anything on the VM path must > do either GFP_ATOMIC or GFP_NOIO allocations, wether it's running > at interrupt time or not. The problem is that the atomic pool is limited, iirc. -- Tom Rini (TR1265) http://gate.crashing.org/~trini/ ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/