From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Moore, Robert" Date: Mon, 1 Dec 2008 09:20:03 -0800 Subject: RE: [patch][rfc] acpi: do not use kmem caches Message-ID: <4911F71203A09E4D9981D27F9D8308580DC5D17C@orsmsx503.amr.corp.intel.com> References: <20081201083128.GB2529@wotan.suse.de> <84144f020812010318v205579ean57edecf7992ec7ef@mail.gmail.com> <20081201120002.GB10790@wotan.suse.de> <4933E2C3.4020400@gmail.com> <1228138641.14439.18.camel@penberg-laptop> <4933EE8A.2010007@gmail.com> <20081201161404.GE10790@wotan.suse.de> <4934149A.4020604@gmail.com> In-Reply-To: <4934149A.4020604@gmail.com> Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: owner-linux-mm@kvack.org Return-Path: To: Alexey Starikovskiy , Nick Piggin Cc: Pekka Enberg , Linux Memory Management List , "linux-acpi@vger.kernel.org" , "lenb@kernel.org" List-ID: As I recall, the ACPICA local cache greatly improves performance of the iASL compiler and AcpiExec on Windows (for BIOS writers, iASL on Windows is most important). >-----Original Message----- >From: linux-acpi-owner@vger.kernel.org [mailto:linux-acpi- >owner@vger.kernel.org] On Behalf Of Alexey Starikovskiy >Sent: Monday, December 01, 2008 8:45 AM >To: Nick Piggin >Cc: Pekka Enberg; Linux Memory Management List; linux-acpi@vger.kernel.org; >lenb@kernel.org >Subject: Re: [patch][rfc] acpi: do not use kmem caches > >Nick Piggin wrote: >> On Mon, Dec 01, 2008 at 05:02:50PM +0300, Alexey Starikovskiy wrote: >> >>> Because SLAB has standard memory wells of 2^x size. None of cached ACPI >>> objects has exactly this size, so bigger block will be used. Plus, >>> internal ACPICA caching will add some overhead. >>> >> >> That's an insane looking caching thing now that I come to closely read >> the code. There is so much stuff there that I thought it must have been >> doing something useful which is why I didn't replace the Linux functions >> with kmalloc/kfree directly. >> >> There is really some operating system you support that has such a poor >> allocator that you think ACPI can do better in 300 lines of code? Why >> not just rip that whole thing out? >> >You would laugh, this is due to Windows userspace debug library -- it >checks for >memory leaks by default, and it takes ages to do this. >And ACPICA maintainer is sitting on Windows, so he _cares_. >>> Do you have another interpreter in kernel space? >>> >> >> So what makes it special? >> >> >You don't know what size of program you will end up with. >DSDT could be almost empty, or you could have several thousand of SSDT >tables. > > > >-- >To unsubscribe from this list: send the line "unsubscribe linux-acpi" in >the body of a message to majordomo@vger.kernel.org >More majordomo info at http://vger.kernel.org/majordomo-info.html -- 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