From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3849DC88E75 for ; Tue, 15 Sep 2026 11:15:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=CxsmxiRqFhUxZGx3gmheUBVs4NM17bV6it+9c2tufGs=; b=byVUm9YqXl26UG Gm14C/MTFVg3pFWfFDyeYOfeB3VkaRMF+F62B7CynuH102TvxsdVcStQEz+D7Q7arQ3SGlop1c0fS t03eKpf0L5cwJVJCwxLPBuKRVPCK4V40Vi5FmZBdr6SYp/UQ1uybnDMiXbKSGI3Dl9QD61vl922wP NsSw1uprnimp0yMJVN5cZTlDHW/9fs5IPD+RBUH42kRMGWag89gtP/GgeSHAen+s0Os8Z04J84Fh3 OKcqcFAoqux6IrvMeD4hSE7dLIWx2kq8sXiOegq6bzFyg8LJZNlXgslELRKX9S1TBZm37e/LOX2uU 9q9KGgp2NnckZY0b424A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x6R8M-00000006407-157Z; Tue, 15 Sep 2026 11:15:30 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x6R8K-000000063zl-0KgQ; Tue, 15 Sep 2026 11:15:28 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 82D63400A3; Tue, 15 Sep 2026 11:15:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 510AF1F000FF; Tue, 15 Sep 2026 11:15:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789470927; bh=CF9ILI9YM/ucBOuS3A2BK2pXreguJU8zji6+GHWCn/8=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=HrcUwFpyn8QxcQDzf1FyVXGhUv9Lvg+4uU5E5bksCbsM9xdWQVrx98pc4yo5aA+mL /smED3Qg96hQ77uOKN5kSpRex+1sMKBAgSH6rVtHuRG0KSweeezfj9161+GZyDIhxu rqyDXPog32TZyUFO9M96tfLSTMSBb1ZwlW2nJ0jhRptBBwghRvEysKhjWr0fcJnc3b ZUCY6fuqbEWIqEpyTj0PILNuJcstedkZMTgj+LfmOeuWZPF1Jd3xSB24NDrnq7CNmo fXjIYvRnslBc73/r7L63E9zDh4vwZ+MVJCsTHtoyA4LPCvTionLdwhARWG6BtGpp7Z 9MAWzvtJ/r/pA== Date: Tue, 15 Sep 2026 12:15:12 +0100 From: "Lorenzo Stoakes (ARM)" To: Miguel Ojeda Cc: Linus Torvalds , Nathan Chancellor , Nicolas Schier , Nick Desaulniers , Bill Wendling , Justin Stitt , Masahiro Yamada , Alexey Gladkov , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Arnd Bergmann , Catalin Marinas , Will Deacon , Mark Rutland , Ard Biesheuvel , Ilias Apalodimas , Josh Poimboeuf , Peter Zijlstra , Miguel Ojeda , Boqun Feng , Gary Guo , =?utf-8?B?QmrDtnJu?= Roy Baron , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Danilo Krummrich , Daniel Almeida , Tamir Duberstein , Alexandre Courbot , Onur =?utf-8?B?w5Z6a2Fu?= , Jonathan Corbet , Randy Dunlap , Kees Cook , "Gustavo A. R. Silva" , linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, linux-riscv@lists.infradead.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-efi@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-doc@vger.kernel.org, Jens Axboe , linux-hardening@vger.kernel.org Subject: Re: [PATCH v2 18/21] kbuild: rust: optionally parallelise rustc front end Message-ID: References: <20260914-build-speedup-v2-0-39817ec5db23@kernel.org> <20260914-build-speedup-v2-18-39817ec5db23@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org T24gVHVlLCBTZXAgMTUsIDIwMjYgYXQgMDc6MzI6MDJBTSArMDEwMCwgTWlndWVsIE9qZWRhIHdy b3RlOgo+IE9uIE1vbiwgU2VwIDE0LCAyMDI2IGF0IDEwOjI04oCvQU0gTG9yZW56byBTdG9ha2Vz IChBUk0pIDxsanNAa2VybmVsLm9yZz4gd3JvdGU6Cj4gPgo+ID4gUnVzdCBjcmF0ZXMgYXJlIGNv bXBpbGVkIGluIGEgc2VyaWFsIGNoYWluIG9uIHRoZSBjcml0aWNhbCBwYXRoIC0gY29yZSwKPiA+ IGJpbmRpbmdzLCBrZXJuZWwgY3JhdGVzIGFuZCB0aGVuIHRoZSBkcml2ZXJzIC0gZWFjaCBhIHJ1 c3RjIGludm9jYXRpb24uCj4KPiBUaGlzIGNvbmZ1c2VkIHRoZSBMV04gYXJ0aWNsZS4uLiA6KQoK U29ycnkgOikKCj4KPiBUaGVyZSBpcyBhIGNyaXRpY2FsIHBhdGggaW4gdGhlIGdyYXBoLCBpbmRl ZWQsIGFuZCBkb2luZyBpdCBpbgo+IGBwcmVwYXJlYCBpcyBwYWluZnVsLCBidXQgdG8gY2xhcmlm eTogZWFjaCBjcmF0ZSBpcyBhbHJlYWR5IGJ1aWx0IGluCj4gcGFyYWxsZWwgd2l0aCBvdGhlcnMg d2hlcmUgcG9zc2libGUsIGFuZCB0aGUgZmFjdCB0aGF0IGVhY2ggY3JhdGUgaXMKPiBidWlsdCBi eSBvbmUgYHJ1c3RjYCBpcyB1bnJlbGF0ZWQsIHBsdXMgdGhlIGZsYWcgdGhpcyBwYXRjaCBwcm9w b3Nlcwo+IGlzIGFsc28gdW5yZWxhdGVkIHRvIHRoYXQuCgpBY2suIEFuZCB0aGUgb3RoZXIgcnVz dCBjaGFuZ2VzIGhlbHAgbWF4aW1pc2UgdGhlIHBhcmFsbGVsaXNhdGlvbgp0aGF0IGV4aXN0cyA6 KQoKPgo+IEkgZ3Vlc3MgdGhlIExMTSB3YXMgdHJ5aW5nIHRvIGFkZCBjb250ZXh0IHRvIHRoZSBu dW1iZXJzIGJlbG93LCBidXQgaXQKPiBsb29rcyBsaWtlIGl0IHdpbGwgZWFzaWx5IGNvbmZ1c2Ug cmVhZGVycy4KPgo+ID4gRWFjaCB0aW1lIGEgY2hhbmdlIGlzIG1hZGUgdG8gYW55IG9mIHRoZSBi aW5kaW5ncywgaXQgdHJpZ2dlcnMgYSByZWJ1aWxkLgo+Cj4gVGhpcyBzZWVtcyBvZGRseSBmb2N1 c2VkIChpLmUuIG5vdCBzdXJlIHdoeSBgYmluZGluZ3NgIGlzIG1lbnRpb25lZCBpbgo+IHBhcnRp Y3VsYXIpLiBJdCBpcyBhbHNvIGF0IGxlYXN0IGluZGVwZW5kZW50IG9mIHRoaXMgcGF0Y2gsIGku ZS4gaXQKPiB3aWxsIHJlbWFpbiB0cnVlIHJlZ2FyZGxlc3Mgb2YgdGhlIHBhdGNoLgo+Cj4gPiBy dXN0YyBoYXMgYSBwYXJhbGxlbCBmcm9udCBlbmQsIGVuYWJsZWQgd2l0aCAtWnRocmVhZHMsIGF2 YWlsYWJsZSBzaW5jZQo+ID4gcnVzdCAxLjg0IFswXSBhbmQgdGhlcmVmb3JlIG9uIGV2ZXJ5IHJ1 c3RjIHRoZSBrZXJuZWwgc3VwcG9ydHMuCj4gPgo+ID4gSXQgaXMgbm90IHlldCBzdGFibGUgYW5k IGl0cyBvdXRwdXQgaXMgbm90IHJlcHJvZHVjaWJsZSwgc28gaXQgY2Fubm90IGJlCj4gPiB1c2Vk IGJ5IGRlZmF1bHQgLSBzdGFiaWxpc2F0aW9uIGlzIGJlaW5nIHdvcmtlZCBvbiBbMV0uCj4KPiBO b3Qgc3VyZSB3aGF0IGl0IG1lYW5zIGJ5ICJieSBkZWZhdWx0Ii4gSW4gYW55IGNhc2UsIHRoZSBt YWluIGlzc3VlCj4gd2l0aCB0aGUgZmxhZyBpcyB0aGF0IGl0IGhhcyBoYWQgaXNzdWVzIHJlY2Vu dGx5LCBub3Qgc28gbXVjaCB0aGUgZmFjdAo+IHRoYXQgaXQgaXMgdW5zdGFibGUuCj4KPiA+IEFk ZCBvcHRpb25hbCBidWlsZCBwYXJhbWV0ZXIgS0JVSUxEX1JVU1RfVEhSRUFEUywgd2hpY2ggd2hl biBzZXQgcGFzc2VzCj4gPiB0aGF0IG1hbnkgdGhyZWFkcyB0byBydXN0Yy4KPiA+Cj4gPiBPYnNl cnZlZCBidWlsZCB0aW1lIGNoYW5nZXMgd2l0aCBLQlVJTERfUlVTVF9USFJFQURTPTggKHJ1c3Rj IDEuOTgsIGNsYW5nKToKPgo+IEkgYXNzdW1lIHRoZSBpbXByb3ZlbWVudHMgYXJlIG1vc3Qgbm90 YWJsZSBkdWUgdG8gdGhlIHdvcmsgYmVpbmcgb24KPiBgcHJlcGFyZWAsIGkuZS4gdGhlcmUgaXMg bm8gb3RoZXIgd29yayBhdmFpbGFibGUuIFdoZW4gdGhhdCBpcwo+IHJlbGF4ZWQsIHRoaXMgc2hv dWxkIGJlIHdheSBsZXNzIG5lZWRlZC4gVGhvdWdoIGl0IHdpbGwgYmUgc3RpbGwgdmVyeQo+IG5p Y2UgdG8gaGF2ZSBmb3IgZnVsbCBSdXN0IHJlYnVpbGRzLCBsaWtlIHdoZW4gY2hhbmdpbmcgdGhl IGNvbXBpbGVyCj4gdmVyc2lvbnMgb2Z0ZW4sIGR1ZSB0byBgY29yZWAgbWFpbmx5IChlLmcuIEkg aGF2ZSB0byBkbyB0aGF0IG9mdGVuLCBzbwo+IEkgd291bGQgbGlrZSBpdCA6KS4KCll1cCB0aGF0 IHN0YWxsaW5nIGlzIHRoZSBrZXkgaXNzdWUuCgpJIG1lYW4gS1JVU1RGTEFHUz0tWnRocmVhZHM9 OCBnaXZlcyB5b3UgYSB3YXkgdG8gYWNoaWV2ZSB0aGF0LCBJJ2xsIHN0aWNrCnRoYXQgaW50byBt eSBzY3JpcHRzIGxvY2FsbHkgZm9yIG5vdyB0b28gSSB0aGluayBhcyBJJ3ZlIGZvdW5kIGl0IHRv IGJlCmNvbXBsZXRlbHkgc3RhYmxlIGF0IGxlYXN0IG9uIG15IG1hY2hpbmUgKFRNKS4KCkJ1dCBk ZWZpbml0ZWx5IGEgVE9ETyB0byBwaW4gZm9yIHlvdSBndXlzIG9uY2UgdGhpcyBpcyBzdGFiaWxp c2VkIC0gaXQKbWFrZXMgYSBiaWcgZGlmZmVyZW5jZSBzbyB3aGVuIGEuIHN0YWJpbGlzZWQgYW5k IGIuIGtlcm5lbCByZXF1aXJlZCBtaW5pbXVtCnZlcnNpb24gaGFzIHRoZSBzdGFiaWxpc2VkIGZl YXR1cmUgLT4gZWFzeSB0byBzd2l0Y2ggb24gOikKCj4KPiBJbiBhbnkgY2FzZSwgSSBhbSBub3Qg c3VyZSBhYm91dCBhZGRpbmcgYSBLYnVpbGQgdmFyaWFibGUgYWxyZWFkeSBmb3IKPiB0aGlzIGF0 IHRoZSBtb21lbnQsIGVzcGVjaWFsbHkgd2l0aCB0aGF0IG5hbWUsIGkuZS4gaXQgaXMgbm90IHJl YWxseQo+ICJ0aHJlYWRzIiBidXQgImZyb250ZW5kIGpvYnMiIGFuZCB0aGUgZmxhZyB3aWxsIG5v dCBiZSBjYWxsZWQgdGhhdCBpbgo+IHRoZSBmdXR1cmUgYW55d2F5Lgo+Cj4gQW5kIGlmIHNvbWVv bmUgd2FudHMgdG8gcmlzayB0aGVpciBrZXJuZWwgYnVpbGRzLCB0aGVuIHRoZXkgY2FuCj4gYWxy ZWFkeSBwYXNzIHRoZSBmbGFnIHRvZGF5Li4uCgpJIGFncmVlLCBiZXN0IHRvIGRyb3AgdGhpcyBp biBnZW5lcmFsLCBkb25lIGZvciB2MyBhbHJlYWR5LiBJJ3ZlIHVwZGF0ZWQKdGhlIGNvdmVyIGxl dHRlciB0byBzYXkgdGhhdCBLUlVTVEZMQUdTPS1adGhyZWFkcz04IGlzIHdoYXQgd2FzIGRvbmUg d2l0aAp0aGUgYnVpbGQuCgo+Cj4gKFdlIHByb2JhYmx5IGFsc28gd2FudCB0byBrbm93IHdoYXQg dGhlIGZsYWcgd2lsbCBmaW5hbGx5IGRvIGJlZm9yZQo+IGNvbW1pdHRpbmcgdG8gcGFydGljdWxh ciBuYW1lcywgZS5nLiB3aGV0aGVyIGl0IGFmZmVjdHMKPiBjb2RlZ2VuL3JlcHJvZHVjaWJpbGl0 eSBpbiBhbnkgd2F5LiBCdXQgcGVyaGFwcyBLYnVpbGQgZG9lc24ndCBtaW5kCj4gaGF2aW5nIG5l dyB2YXJpYWJsZXMgdGhhdCBtYXkgYmUgcmVwbGFjZWQgc29vbi4pCgpJIGRvbid0IHRoaW5rIGl0 J3MgdG9vIGVncmVnaW91cyBlaXRoZXIgd2F5IHRiaCwgYnV0IGluIGFueSBjYXNlIGRyb3BwaW5n CnRoaXMgZm9yIG5vdyBpcyB0aGUgd2F5IHRvIGdvLgoKPgo+IFRoYW5rcyEKPgo+IENoZWVycywK PiBNaWd1ZWwKCi0tCkNoZWVycywgTG9yZW56bwoKX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX18KbGludXgtcmlzY3YgbWFpbGluZyBsaXN0CmxpbnV4LXJpc2N2 QGxpc3RzLmluZnJhZGVhZC5vcmcKaHR0cDovL2xpc3RzLmluZnJhZGVhZC5vcmcvbWFpbG1hbi9s aXN0aW5mby9saW51eC1yaXNjdgo=