From 0415b00d175e0d8945e6785aad21b5f157976ce0 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 24 Mar 2011 18:50:09 +0100 Subject: percpu: Always align percpu output section to PAGE_SIZE Percpu allocator honors alignment request upto PAGE_SIZE and both the percpu addresses in the percpu address space and the translated kernel addresses should be aligned accordingly. The calculation of the former depends on the alignment of percpu output section in the kernel image. The linker script macros PERCPU_VADDR() and PERCPU() are used to define this output section and the latter takes @align parameter. Several architectures are using @align smaller than PAGE_SIZE breaking percpu memory alignment. This patch removes @align parameter from PERCPU(), renames it to PERCPU_SECTION() and makes it always align to PAGE_SIZE. While at it, add PCPU_SETUP_BUG_ON() checks such that alignment problems are reliably detected and remove percpu alignment comment recently added in workqueue.c as the condition would trigger BUG way before reaching there. For um, this patch raises the alignment of percpu area. As the area is in .init, there shouldn't be any noticeable difference. This problem was discovered by David Howells while debugging boot failure on mn10300. Signed-off-by: Tejun Heo Acked-by: Mike Frysinger Cc: uclinux-dist-devel@blackfin.uclinux.org Cc: David Howells Cc: Jeff Dike Cc: user-mode-linux-devel@lists.sourceforge.net --- mm/percpu.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'mm/percpu.c') diff --git a/mm/percpu.c b/mm/percpu.c index 3f930018aa60..c5feb79f5995 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -1216,8 +1216,10 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, PCPU_SETUP_BUG_ON(ai->nr_groups <= 0); #ifdef CONFIG_SMP PCPU_SETUP_BUG_ON(!ai->static_size); + PCPU_SETUP_BUG_ON((unsigned long)__per_cpu_start & ~PAGE_MASK); #endif PCPU_SETUP_BUG_ON(!base_addr); + PCPU_SETUP_BUG_ON((unsigned long)base_addr & ~PAGE_MASK); PCPU_SETUP_BUG_ON(ai->unit_size < size_sum); PCPU_SETUP_BUG_ON(ai->unit_size & ~PAGE_MASK); PCPU_SETUP_BUG_ON(ai->unit_size < PCPU_MIN_UNIT_SIZE); -- cgit v1.2.1 From 787e5b06a80e7fc9dc02d9b53a9d8d2ac63b7ace Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Wed, 23 Mar 2011 08:23:52 +0100 Subject: percpu: Cast away printk format warning On 32-bit systems which don't happen to implicitly define or cast VMALLOC_START and/or VMALLOC_END to long in their arch headers, the printk in the percpu code will cause a warning to be emitted: mm/percpu.c: In function 'pcpu_embed_first_chunk': mm/percpu.c:1648: warning: format '%lx' expects type 'long unsigned int', but argument 3 has type 'unsigned int' So add an explicit cast to unsigned long here. Signed-off-by: Mike Frysinger Signed-off-by: Tejun Heo --- mm/percpu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'mm/percpu.c') diff --git a/mm/percpu.c b/mm/percpu.c index 3f930018aa60..8a11cd2e976d 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -1646,8 +1646,8 @@ int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size, /* warn if maximum distance is further than 75% of vmalloc space */ if (max_distance > (VMALLOC_END - VMALLOC_START) * 3 / 4) { pr_warning("PERCPU: max_distance=0x%zx too large for vmalloc " - "space 0x%lx\n", - max_distance, VMALLOC_END - VMALLOC_START); + "space 0x%lx\n", max_distance, + (unsigned long)(VMALLOC_END - VMALLOC_START)); #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK /* and fail if we have fallback */ rc = -EINVAL; -- cgit v1.2.1