From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx138.postini.com [74.125.245.138]) by kanga.kvack.org (Postfix) with SMTP id C83426B0032 for ; Thu, 27 Jun 2013 18:02:32 -0400 (EDT) Date: Thu, 27 Jun 2013 15:02:31 -0700 From: Andrew Morton Subject: Re: [PATCH v2] vmpressure: implement strict mode Message-Id: <20130627150231.2bc00e3efcd426c4beef894c@linux-foundation.org> In-Reply-To: <20130626231712.4a7392a7@redhat.com> References: <20130626231712.4a7392a7@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: Luiz Capitulino Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, mhocko@suse.cz, minchan@kernel.org, anton@enomsg.org, kmpark@infradead.org, hyunhee.kim@samsung.com On Wed, 26 Jun 2013 23:17:12 -0400 Luiz Capitulino wrote: > Currently, an eventfd is notified for the level it's registered for > _plus_ higher levels. > > This is a problem if an application wants to implement different > actions for different levels. For example, an application might want > to release 10% of its cache on level low, 50% on medium and 100% on > critical. To do this, an application has to register a different > eventfd for each pressure level. However, fd low is always going to > be notified and and all fds are going to be notified on level critical. > > Strict mode solves this problem by strictly notifiying an eventfd > for the pressure level it registered for. This new mode is optional, > by default we still notify eventfds on higher levels too. > It didn't take long for this simple interface to start getting ugly :( And having the fd operate in different modes is ugly. Can we instead pass the level in the event payload? -- 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