From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx142.postini.com [74.125.245.142]) by kanga.kvack.org (Postfix) with SMTP id B5D5E6B0031 for ; Tue, 2 Jul 2013 10:15:43 -0400 (EDT) Date: Tue, 2 Jul 2013 14:15:42 +0000 From: Christoph Lameter Subject: Re: [PATCH 1/3] mm/slub: Fix slub calculate active slabs uncorrectly In-Reply-To: <51d218df.a77d440a.3cfe.ffffe64aSMTPIN_ADDED_BROKEN@mx.google.com> Message-ID: <0000013f9fbd247d-8de715f1-e0dc-47fb-8f06-af6c061044be-000000@email.amazonses.com> References: <1372291059-9880-1-git-send-email-liwanp@linux.vnet.ibm.com> <0000013f9b8d6897-d2399224-d203-4dc5-a700-90dea9be7536-000000@email.amazonses.com> <51d218df.a77d440a.3cfe.ffffe64aSMTPIN_ADDED_BROKEN@mx.google.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Wanpeng Li Cc: Pekka Enberg , Matt Mackall , Glauber Costa , Andrew Morton , Joonsoo Kim , David Rientjes , linux-mm@kvack.org, linux-kernel@vger.kernel.org On Tue, 2 Jul 2013, Wanpeng Li wrote: > Before patch: > Active / Total Slabs (% used) : 59018 / 59018 (100.0%) > > After patch: > Active / Total Slabs (% used) : 11086 / 11153 (99.4%) Yes I saw that. > These numbers are dump from slabtop for monitor slub, before patch Active / Total > Slabs are always 100%, this is not truth since empty slabs present. However, the > slab allocator can caculate its Active / Total Slabs correctly and its value is > less than 100.0%. By comparison, slub is more efficient than slab through slabtop > observation, however, it is not truth since slub uncorrectly calculate its > Active / Total Slabs. I always thought about the "empty" slabs to be active since they are used for allocation and frees like the other partial slabs. -- 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