From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qg0-f42.google.com (mail-qg0-f42.google.com [209.85.192.42]) by kanga.kvack.org (Postfix) with ESMTP id EE1836B0006 for ; Fri, 18 Dec 2015 11:33:39 -0500 (EST) Received: by mail-qg0-f42.google.com with SMTP id p62so6809820qge.1 for ; Fri, 18 Dec 2015 08:33:39 -0800 (PST) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id y69si16829131qka.73.2015.12.18.08.33.38 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 18 Dec 2015 08:33:38 -0800 (PST) Date: Fri, 18 Dec 2015 17:33:33 +0100 From: Igor Mammedov Subject: Re: [PATCH] memory-hotplug: don't BUG() in register_memory_resource() Message-ID: <20151218173333.624b2867@nial.brq.redhat.com> In-Reply-To: <1450450224-18515-1-git-send-email-vkuznets@redhat.com> References: <1450450224-18515-1-git-send-email-vkuznets@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Vitaly Kuznetsov Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Tang Chen , Naoya Horiguchi , Xishi Qiu , Sheng Yong , David Rientjes , Zhu Guihua , Dan Williams , David Vrabel On Fri, 18 Dec 2015 15:50:24 +0100 Vitaly Kuznetsov wrote: > Out of memory condition is not a bug and while we can't add new memory in > such case crashing the system seems wrong. Propagating the return value > from register_memory_resource() requires interface change. > > Cc: Andrew Morton > Cc: Tang Chen > Cc: Naoya Horiguchi > Cc: Xishi Qiu > Cc: Sheng Yong > Cc: David Rientjes > Cc: Zhu Guihua > Cc: Dan Williams > Cc: David Vrabel > Cc: Igor Mammedov > Signed-off-by: Vitaly Kuznetsov > --- > mm/memory_hotplug.c | 17 ++++++++++------- > 1 file changed, 10 insertions(+), 7 deletions(-) > > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index 67d488a..9392f01 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -127,11 +127,13 @@ void mem_hotplug_done(void) > } > > /* add this memory to iomem resource */ > -static struct resource *register_memory_resource(u64 start, u64 size) > +static int register_memory_resource(u64 start, u64 size, > + struct resource **resource) > { > struct resource *res; > res = kzalloc(sizeof(struct resource), GFP_KERNEL); > - BUG_ON(!res); > + if (!res) > + return -ENOMEM; > > res->name = "System RAM"; > res->start = start; > @@ -140,9 +142,10 @@ static struct resource *register_memory_resource(u64 start, u64 size) > if (request_resource(&iomem_resource, res) < 0) { > pr_debug("System RAM resource %pR cannot be added\n", res); > kfree(res); > - res = NULL; > + return -EEXIST; > } > - return res; > + *resource = res; > + return 0; > } > > static void release_memory_resource(struct resource *res) > @@ -1311,9 +1314,9 @@ int __ref add_memory(int nid, u64 start, u64 size) > struct resource *res; > int ret; > > - res = register_memory_resource(start, size); > - if (!res) > - return -EEXIST; > + ret = register_memory_resource(start, size, &res); > + if (ret) > + return ret; > > ret = add_memory_resource(nid, res); > if (ret < 0) Reviewed-by: Igor Mammedov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org