From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk1-f198.google.com (mail-qk1-f198.google.com [209.85.222.198]) by kanga.kvack.org (Postfix) with ESMTP id 9641C8E0072 for ; Tue, 25 Sep 2018 05:15:49 -0400 (EDT) Received: by mail-qk1-f198.google.com with SMTP id y130-v6so25485711qka.1 for ; Tue, 25 Sep 2018 02:15:49 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id x5-v6si1353666qte.88.2018.09.25.02.15.48 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 25 Sep 2018 02:15:48 -0700 (PDT) From: David Hildenbrand Subject: [PATCH v2 5/6] powerpc/powernv: hold device_hotplug_lock when calling memtrace_offline_pages() Date: Tue, 25 Sep 2018 11:14:56 +0200 Message-Id: <20180925091457.28651-6-david@redhat.com> In-Reply-To: <20180925091457.28651-1-david@redhat.com> References: <20180925091457.28651-1-david@redhat.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org, xen-devel@lists.xenproject.org, devel@linuxdriverproject.org, David Hildenbrand , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Rashmica Gupta , Balbir Singh , Michael Neuling Let's perform all checking + offlining + removing under device_hotplug_lock, so nobody can mess with these devices via sysfs concurrently. Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Rashmica Gupta Cc: Balbir Singh Cc: Michael Neuling Reviewed-by: Pavel Tatashin Reviewed-by: Rashmica Gupta Signed-off-by: David Hildenbrand --- arch/powerpc/platforms/powernv/memtrace.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/platforms/powernv/memtrace.c b/arch/powerpc/platforms/powernv/memtrace.c index fdd48f1a39f7..d84d09c56af9 100644 --- a/arch/powerpc/platforms/powernv/memtrace.c +++ b/arch/powerpc/platforms/powernv/memtrace.c @@ -70,6 +70,7 @@ static int change_memblock_state(struct memory_block *mem, void *arg) return 0; } +/* called with device_hotplug_lock held */ static bool memtrace_offline_pages(u32 nid, u64 start_pfn, u64 nr_pages) { u64 end_pfn = start_pfn + nr_pages - 1; @@ -111,6 +112,7 @@ static u64 memtrace_alloc_node(u32 nid, u64 size) end_pfn = round_down(end_pfn - nr_pages, nr_pages); for (base_pfn = end_pfn; base_pfn > start_pfn; base_pfn -= nr_pages) { + lock_device_hotplug(); if (memtrace_offline_pages(nid, base_pfn, nr_pages) == true) { /* * Remove memory in memory block size chunks so that @@ -118,7 +120,6 @@ static u64 memtrace_alloc_node(u32 nid, u64 size) * we never try to remove memory that spans two iomem * resources. */ - lock_device_hotplug(); end_pfn = base_pfn + nr_pages; for (pfn = base_pfn; pfn < end_pfn; pfn += bytes>> PAGE_SHIFT) { __remove_memory(nid, pfn << PAGE_SHIFT, bytes); @@ -126,6 +127,7 @@ static u64 memtrace_alloc_node(u32 nid, u64 size) unlock_device_hotplug(); return base_pfn << PAGE_SHIFT; } + unlock_device_hotplug(); } return 0; -- 2.17.1