Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965012AbWHWQJc (ORCPT ); Wed, 23 Aug 2006 12:09:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965014AbWHWQJc (ORCPT ); Wed, 23 Aug 2006 12:09:32 -0400 Received: from gundega.hpl.hp.com ([192.6.19.190]:48841 "EHLO gundega.hpl.hp.com") by vger.kernel.org with ESMTP id S965012AbWHWQJc (ORCPT ); Wed, 23 Aug 2006 12:09:32 -0400 Date: Wed, 23 Aug 2006 08:53:21 -0700 From: Stephane Eranian To: Christoph Hellwig , Andi Kleen , linux-kernel@vger.kernel.org Subject: Re: [PATCH 18/18] 2.6.17.9 perfmon2 patch for review: new x86_64 files Message-ID: <20060823155321.GD1733@frankl.hpl.hp.com> Reply-To: eranian@hpl.hp.com References: <200608230806.k7N869KD000552@frankl.hpl.hp.com> <20060823102932.GA697@frankl.hpl.hp.com> <20060823152555.GA32725@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060823152555.GA32725@infradead.org> User-Agent: Mutt/1.4.1i Organisation: HP Labs Palo Alto Address: HP Labs, 1U-17, 1501 Page Mill road, Palo Alto, CA 94304, USA. E-mail: eranian@hpl.hp.com X-HPL-MailScanner: Found to be clean X-HPL-MailScanner-From: eranian@frankl.hpl.hp.com Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1220 Lines: 37 Christoph, On Wed, Aug 23, 2006 at 04:25:55PM +0100, Christoph Hellwig wrote: > On Wed, Aug 23, 2006 at 03:29:32AM -0700, Stephane Eranian wrote: > > > > +#define PFM_EM64T_PEBS_SMPL_UUID { \ > > > > + 0x36, 0xbe, 0x97, 0x94, 0x1f, 0xbf, 0x41, 0xdf,\ > > > > + 0xb4, 0x63, 0x10, 0x62, 0xeb, 0x72, 0x9b, 0xad} > > > > > > What does it need the UUID for? > > > > > Every sampling format is identified by a UUID. This is how an > > application can identify the format it wants to use when it > > creates a context. > > Please use a string name, just like every other interface for > such selections. What are the advantages at the syscall level (i.e., copy_user, format parsing) compared to a 16-entry byte array? We are passing that uuid into a struct: struct pfarg_ctx { __u8 ctx_smpl_buf_id[16]; __u32 ctx_flags; __s32 ctx_fd; __u64 ctx_smpl_buf_size; __u64 ctx_reserved3[12]; }; -- -Stephane - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/