From mboxrd@z Thu Jan 1 00:00:00 1970 From: Balbir Singh Subject: Re: [RFC/T/D][PATCH 2/2] Linux/Guest cooperative unmapped page cache control Date: Mon, 14 Jun 2010 23:10:08 +0530 Message-ID: <20100614174008.GA5191@balbir.in.ibm.com> References: <20100608155140.3749.74418.sendpatchset@L34Z31A.ibm.com> <20100608155153.3749.31669.sendpatchset@L34Z31A.ibm.com> <4C10B3AF.7020908@redhat.com> <20100610142512.GB5191@balbir.in.ibm.com> <1276214852.6437.1427.camel@nimitz> <20100611045600.GE5191@balbir.in.ibm.com> <4C15E3C8.20407@redhat.com> <20100614084810.GT5191@balbir.in.ibm.com> <1276528376.6437.7176.camel@nimitz> <4C164C22.1050503@redhat.com> Reply-To: balbir@linux.vnet.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Cc: Dave Hansen , kvm , linux-mm@kvack.org, linux-kernel@vger.kernel.org To: Avi Kivity Return-path: Content-Disposition: inline In-Reply-To: <4C164C22.1050503@redhat.com> Sender: owner-linux-mm@kvack.org List-Id: kvm.vger.kernel.org * Avi Kivity [2010-06-14 18:34:58]: > On 06/14/2010 06:12 PM, Dave Hansen wrote: > >On Mon, 2010-06-14 at 14:18 +0530, Balbir Singh wrote: > >>1. A slab page will not be freed until the entire page is free (all > >>slabs have been kfree'd so to speak). Normal reclaim will definitely > >>free this page, but a lot of it depends on how frequently we are > >>scanning the LRU list and when this page got added. > >You don't have to be freeing entire slab pages for the reclaim to have > >been useful. You could just be making space so that _future_ > >allocations fill in the slab holes you just created. You may not be > >freeing pages, but you're reducing future system pressure. > > Depends. If you've evicted something that will be referenced soon, > you're increasing system pressure. > I don't think slab pages care about being referenced soon, they are either allocated or freed. A page is just a storage unit for the data structure. A new one can be allocated on demand. -- Three Cheers, Balbir -- 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