From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by sourceware.org (Postfix) with ESMTPS id AE6A7385800F for ; Sat, 27 Mar 2021 09:58:57 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org AE6A7385800F Received: by mail.kernel.org (Postfix) with ESMTPSA id 3366161937; Sat, 27 Mar 2021 09:58:55 +0000 (UTC) Date: Sat, 27 Mar 2021 10:58:52 +0100 From: Greg KH To: Len Brown Cc: Andy Lutomirski , "Bae, Chang Seok" , Dave Hansen , X86 ML , LKML , libc-alpha , Florian Weimer , Rich Felker , Kyle Huey , Keno Fischer , Linux API Subject: Re: Candidate Linux ABI for Intel AMX and hypothetical new related features Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 27 Mar 2021 09:58:58 -0000 On Fri, Mar 26, 2021 at 11:39:18PM -0400, Len Brown wrote: > Hi Andy, > > Say a mainline links with a math library that uses AMX without the > knowledge of the mainline. What does this mean? What happened to the context here? > Say the mainline is also linked with a userspace threading library > that thinks it has a concept of XSAVE area size. How can the kernel (what I think you mean by "mainline" here) be linked with a userspace library at all? > Wouldn't the change in XCR0, resulting in XSAVE size change, risk > confusing the threading library? Shouldn't that be the job of the kernel and not userspace? totally confused, greg k-h