From mboxrd@z Thu Jan 1 00:00:00 1970 From: Giuseppe CAVALLARO Date: Fri, 13 Feb 2009 10:16:00 +0000 Subject: Re: [PATCH] slab: fix slab flags for archs use alignment larger Message-Id: <4995565D.5010105@st.com> List-Id: References: <1234461073-23281-1-git-send-email-peppe.cavallaro@st.com> <20090212185640.GA6111@linux-sh.org> <499544AD.3030804@st.com> <84144f020902130122y471dd92em4a72de43a0cfc681@mail.gmail.com> <49954F9A.5020801@st.com> <84144f020902130205x4dc5886l70fe6a695ef050a4@mail.gmail.com> In-Reply-To: <84144f020902130205x4dc5886l70fe6a695ef050a4@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Pekka Enberg Cc: Paul Mundt , linux-kernel@vger.kernel.org, linux-sh@vger.kernel.org, linux-mm@vger.kernel.org, Christoph Lameter Pekka Enberg wrote: > Hi Giuseppe, > > On Fri, Feb 13, 2009 at 12:46 PM, Giuseppe CAVALLARO > wrote: > >> 1) LOG with my patch: >> root@linux:~# cat /proc/meminfo | grep Slab >> Slab: 2612 kB >> >> 2) LOG without my patch: >> root@linux:~# cat /proc/meminfo | grep Slab >> Slab: 2504 kB >> > > That's not too bad. I assume it's L1_CACHE_BYTES set to 32 bytes? you are perfectly right. > One big problem with your patch is that on some MIPS configurations > ARCH_KMALLOC_MINALIGN is as big as 128. Agree again and problem understood... thanks! > So if you're going to do this, you can't use ARCH_KMALLOC_MINALIGN directly but add a some > SLAB_MAX_DEBUG_ALIGN which can be overridden by architecture code. > If you like, I can prepare a patch in any case. Then we can decide if it actually adds complexity and discard it. Otherwise we could maintain it. > One obvious question, though, is whether all this is worth the added > complexity. I mean, we've managed "just fine" without it for years. > Paul, thoughts? > > Pekka > >