From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by ey-out-1920.google.com with SMTP id 21so1346106eyc.44 for ; Mon, 01 Dec 2008 09:36:53 -0800 (PST) Message-ID: <493420B2.8050907@gmail.com> Date: Mon, 01 Dec 2008 20:36:50 +0300 From: Alexey Starikovskiy MIME-Version: 1.0 Subject: Re: [patch][rfc] acpi: do not use kmem caches References: <20081201083128.GB2529@wotan.suse.de> <20081201120002.GB10790@wotan.suse.de> <4933E2C3.4020400@gmail.com> <1228138641.14439.18.camel@penberg-laptop> <4933F925.3020907@gmail.com> <20081201162018.GF10790@wotan.suse.de> <49341915.5000900@gmail.com> <20081201171219.GI10790@wotan.suse.de> <84144f020812010925r6c5f9c85p32f180c06085b496@mail.gmail.com> <84144f020812010932l540b26dr57716d8abea2562@mail.gmail.com> In-Reply-To: <84144f020812010932l540b26dr57716d8abea2562@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Pekka Enberg Cc: Nick Piggin , Christoph Lameter , Linux Memory Management List , linux-acpi@vger.kernel.org, lenb@kernel.org List-ID: Pekka Enberg wrote: > On Mon, Dec 1, 2008 at 7:25 PM, Pekka Enberg wrote: > >> Though I suspect using kmem caches to combat the internal >> fragmentation caused by kmalloc() rounding is not worth it in this >> case. >> > > Btw, just for the record, the ACPI objects are indeed a bad fit for > kmalloc() as reported by SLUB statistics: > > [ The size of ACPI kmem caches with wasted bytes per object in parenthesis. ] > > 32-bit size 64-bit size > Acpi-Namespace 24 (8) 32 (0) > Acpi-Operand 40 (24) 72 (24) > Acpi-Parse 32 (0) 48 (16) > Acpi-ParseExt 44 (20) 72 (24) > Acpi-State 44 (20) 80 (16) > > Though I suspect this situation could be improved by avoiding those > fairly big unions ACPI does (like union acpi_operand_object). > No, last time I checked, operand may get down to 16 bytes in 32-bit case -- save byte by having 3 types of operands... and making 2 more caches :) -- 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