From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f50.google.com (mail-pa0-f50.google.com [209.85.220.50]) by kanga.kvack.org (Postfix) with ESMTP id 991346B0038 for ; Wed, 11 Feb 2015 15:39:53 -0500 (EST) Received: by mail-pa0-f50.google.com with SMTP id hz1so6350960pad.9 for ; Wed, 11 Feb 2015 12:39:53 -0800 (PST) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id e4si2184330pas.199.2015.02.11.12.39.49 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 11 Feb 2015 12:39:49 -0800 (PST) Date: Wed, 11 Feb 2015 12:39:47 -0800 From: Andrew Morton Subject: Re: [PATCH 1/3] driver core: export lock_device_hotplug/unlock_device_hotplug Message-Id: <20150211123947.3318933f2aca54e11324b088@linux-foundation.org> In-Reply-To: <1423669462-30918-2-git-send-email-vkuznets@redhat.com> References: <1423669462-30918-1-git-send-email-vkuznets@redhat.com> <1423669462-30918-2-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: Greg Kroah-Hartman , "K. Y. Srinivasan" , Haiyang Zhang , Yasuaki Ishimatsu , Tang Chen , Vlastimil Babka , David Rientjes , Fabian Frederick , Zhang Zhen , Vladimir Davydov , Wang Nan , linux-kernel@vger.kernel.org, devel@linuxdriverproject.org, linux-mm@kvack.org, "Rafael J. Wysocki" On Wed, 11 Feb 2015 16:44:20 +0100 Vitaly Kuznetsov wrote: > add_memory() is supposed to be run with device_hotplug_lock grabbed, otherwise > it can race with e.g. device_online(). Allow external modules (hv_balloon for > now) to lock device hotplug. > > ... > > --- a/drivers/base/core.c > +++ b/drivers/base/core.c > @@ -55,11 +55,13 @@ void lock_device_hotplug(void) > { > mutex_lock(&device_hotplug_lock); > } > +EXPORT_SYMBOL_GPL(lock_device_hotplug); > > void unlock_device_hotplug(void) > { > mutex_unlock(&device_hotplug_lock); > } > +EXPORT_SYMBOL_GPL(unlock_device_hotplug); > > int lock_device_hotplug_sysfs(void) > { It's kinda crazy that lock_device_hotplug_sysfs() didn't get any documentation. I suggest adding this while you're in there: --- a/drivers/base/core.c~a +++ a/drivers/base/core.c @@ -61,6 +61,9 @@ void unlock_device_hotplug(void) mutex_unlock(&device_hotplug_lock); } +/* + * "git show 5e33bc4165f3ed" for details + */ int lock_device_hotplug_sysfs(void) { if (mutex_trylock(&device_hotplug_lock)) which is a bit lazy but whatev. I'll assume that Greg (or Rafael?) will be processing this patchset. -- 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