From 127493d5dc73589cbe00ea5ec8357cc2a4c0d82a Mon Sep 17 00:00:00 2001 From: Nishanth Aravamudan Date: Wed, 13 Apr 2011 19:45:59 +0000 Subject: [PATCH] powerpc/pseries: Use a kmem cache for DTL buffers 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. Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/platforms/pseries/setup.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c index 000724149089..6c42cfde8415 100644 --- a/arch/powerpc/platforms/pseries/setup.c +++ b/arch/powerpc/platforms/pseries/setup.c @@ -287,14 +287,22 @@ 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); + if (!dtl_cache) { + pr_warn("Failed to create dispatch trace log buffer cache\n"); + pr_warn("Stolen time statistics will be unreliable\n"); + return 0; + } + 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); -- 2.20.1