From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 41vnPK6N45zF1R0 for ; Tue, 21 Aug 2018 20:44:53 +1000 (AEST) From: David Hildenbrand 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 Subject: [PATCH RFCv2 5/6] powerpc/powernv: hold device_hotplug_lock in memtrace_offline_pages() Date: Tue, 21 Aug 2018 12:44:17 +0200 Message-Id: <20180821104418.12710-6-david@redhat.com> In-Reply-To: <20180821104418.12710-1-david@redhat.com> References: <20180821104418.12710-1-david@redhat.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 Signed-off-by: David Hildenbrand --- arch/powerpc/platforms/powernv/memtrace.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/platforms/powernv/memtrace.c b/arch/powerpc/platforms/powernv/memtrace.c index ef7181d4fe68..473e59842ec5 100644 --- a/arch/powerpc/platforms/powernv/memtrace.c +++ b/arch/powerpc/platforms/powernv/memtrace.c @@ -74,9 +74,13 @@ static bool memtrace_offline_pages(u32 nid, u64 start_pfn, u64 nr_pages) { u64 end_pfn = start_pfn + nr_pages - 1; + lock_device_hotplug(); + if (walk_memory_range(start_pfn, end_pfn, NULL, - check_memblock_online)) + check_memblock_online)) { + unlock_device_hotplug(); return false; + } walk_memory_range(start_pfn, end_pfn, (void *)MEM_GOING_OFFLINE, change_memblock_state); @@ -84,14 +88,16 @@ static bool memtrace_offline_pages(u32 nid, u64 start_pfn, u64 nr_pages) if (offline_pages(start_pfn, nr_pages)) { walk_memory_range(start_pfn, end_pfn, (void *)MEM_ONLINE, change_memblock_state); + unlock_device_hotplug(); return false; } walk_memory_range(start_pfn, end_pfn, (void *)MEM_OFFLINE, change_memblock_state); - remove_memory(nid, start_pfn << PAGE_SHIFT, nr_pages << PAGE_SHIFT); + __remove_memory(nid, start_pfn << PAGE_SHIFT, nr_pages << PAGE_SHIFT); + unlock_device_hotplug(); return true; } -- 2.17.1