From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e9.ny.us.ibm.com (e9.ny.us.ibm.com [32.97.182.139]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e9.ny.us.ibm.com", Issuer "Equifax" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id 5D7AEB7104 for ; Thu, 14 Apr 2011 15:13:52 +1000 (EST) Received: from d01dlp02.pok.ibm.com (d01dlp02.pok.ibm.com [9.56.224.85]) by e9.ny.us.ibm.com (8.14.4/8.13.1) with ESMTP id p3E4jqM4032482 for ; Thu, 14 Apr 2011 00:45:52 -0400 Received: from d01relay03.pok.ibm.com (d01relay03.pok.ibm.com [9.56.227.235]) by d01dlp02.pok.ibm.com (Postfix) with ESMTP id 7A0BB6E8039 for ; Thu, 14 Apr 2011 01:13:48 -0400 (EDT) Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by d01relay03.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p3E5DmvZ338098 for ; Thu, 14 Apr 2011 01:13:48 -0400 Received: from d01av03.pok.ibm.com (loopback [127.0.0.1]) by d01av03.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p3E5Dl9q019308 for ; Thu, 14 Apr 2011 02:13:48 -0300 From: Nishanth Aravamudan To: Michael Ellerman Subject: [PATCH v3] powerpc: use a kmem cache for DTL buffers Date: Wed, 13 Apr 2011 22:13:46 -0700 Message-Id: <1302758026-29313-1-git-send-email-nacc@us.ibm.com> In-Reply-To: <1302754363.12513.89.camel@concordia> References: <1302754363.12513.89.camel@concordia> Cc: linuxppc-dev@lists.ozlabs.org, Paul Mackerras , Anton Blanchard List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , PAPR specifies that DTL buffers can not cross AMS environments (aka CMO in the PAPR) and can not cross a memory entitlement granule boundary (4k). This is found in section 14.11.3.2 H_REGISTER_VPA of the PAPR. kmalloc does not guarantee an alignment of the allocation, though, beyond 8 bytes (at least in my understanding). Create a special kmem cache for DTL buffers with the alignment requirement. --- Change from v1: removed extraneous #include. Change from v2: instead of overallocating and aligning, use a kmem cache Note, I initially put this in a firmware check if-block, but we have also seen some issues with alignment with non-AMS partitions. The wasted memory is unfortunate, though. Signed-off-by: Nishanth Aravamudan Cc: Paul Mackerras Cc: Ben Herrenschmidt Cc: Anton Blanchard Cc: linuxppc-dev@lists.ozlabs.org arch/powerpc/platforms/pseries/setup.c | 7 +++++-- 1 files changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c index 0007241..629b703 100644 --- a/arch/powerpc/platforms/pseries/setup.c +++ b/arch/powerpc/platforms/pseries/setup.c @@ -287,14 +287,17 @@ static int alloc_dispatch_logs(void) int cpu, ret; struct paca_struct *pp; struct dtl_entry *dtl; + struct kmem_cache *dtl_cache; if (!firmware_has_feature(FW_FEATURE_SPLPAR)) return 0; + dtl_cache = kmem_cache_create("dtl", DISPATCH_LOG_BYTES, + DISPATCH_LOG_BYTES, 0, NULL); + for_each_possible_cpu(cpu) { pp = &paca[cpu]; - dtl = kmalloc_node(DISPATCH_LOG_BYTES, GFP_KERNEL, - cpu_to_node(cpu)); + dtl = kmem_cache_alloc(dtl_cache, GFP_KERNEL); if (!dtl) { pr_warn("Failed to allocate dispatch trace log for cpu %d\n", cpu); -- 1.7.4.1