From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate001.proxmox.com (gate001.proxmox.com [45.144.208.40]) by lore.proxmox.com (Postfix) with ESMTPS id 339331FF13A for ; Wed, 08 Jul 2026 09:12:09 +0200 (CEST) Received: from gate001.proxmox.com (localhost.localdomain [127.0.0.1]) by gate001.proxmox.com (Proxmox) with ESMTP id C70A221441; Wed, 08 Jul 2026 09:12:08 +0200 (CEST) Date: Wed, 08 Jul 2026 09:11:28 +0200 From: Fabian =?iso-8859-1?q?Gr=FCnbichler?= Subject: Re: [PATCH datacenter-manager 2/3] ui: d/rules: use thin instead of fat LTO To: Dominik Csapak , pdm-devel@lists.proxmox.com, Thomas Lamprecht References: <20260706114822.2751086-1-d.csapak@proxmox.com> <20260706114822.2751086-3-d.csapak@proxmox.com> <1783433095.x62omid41h.astroid@yuna.none> <5b842f53-3059-4ac2-9e7a-4a7a04132ace@proxmox.com> In-Reply-To: <5b842f53-3059-4ac2-9e7a-4a7a04132ace@proxmox.com> MIME-Version: 1.0 User-Agent: astroid/0.17.0 (https://github.com/astroidmail/astroid) Message-Id: <1783494290.vpra89xkg7.astroid@yuna.none> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Bm-Milter-Handled: 55990f41-d878-4baa-be0a-ee34c49e34d2 X-Bm-Transport-Timestamp: 1783494682815 X-SPAM-LEVEL: Spam detection results: 0 AWL 0.080 Adjusted score from AWL reputation of From: address DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment (newer systems) SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Message-ID-Hash: JS5RI7IR7BOV76C6UGP6TDB4CLAIAXKE X-Message-ID-Hash: JS5RI7IR7BOV76C6UGP6TDB4CLAIAXKE X-MailFrom: f.gruenbichler@proxmox.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; loop; banned-address; emergency; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.10 Precedence: list List-Id: Proxmox Datacenter Manager development discussion List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: On July 7, 2026 11:53 pm, Thomas Lamprecht wrote: > Am 07.07.26 um 16:06 schrieb Fabian Gr=C3=BCnbichler: >> On July 6, 2026 1:44 pm, Dominik Csapak wrote: >>> fat LTO merges all LLVM modules into a single unit for optimizing. >>> Changing this to thin LTO increases the uncompressed binary size by 1.5= 9 >>> MiB (+11%) (compressed +192KiB/+4.6%) but save us ~160s (-40%) of (wall= ) >>> build time during a 'make deb'. >> but what are the effects on runtime performance? the same question also >> applies to the next patch, a single codegen unit increases the amount of >> optimizations the compiler can do.. >=20 > FWIW, https://docs.wasmtime.dev/examples-minimal.html states: >=20 > """ > Note that with LTO using a single codegen unit may only have marginal ben= efit. > If not using LTO, however, a single codegen unit will likely provide bene= fit over the default 16 codegen units. > """ >=20 > If that (still) holds, we currently do the worst of both worlds compile > time wise while not really profiting from this. I'd probably try dropping > overriding codegen units first (we do not lower that on performance other > (non-wasm) critical code either, e.g. PBS. Most perf related documentation seems to say codegen-units=3D1 and LTO=3Dfa= t are the way to go if you want to optimize for performance, though whether that is true for wasm I don't know (the documentation there is quite messy/outdated). AFAIK, it's how projects optimizing for performance build their release binaries (i.e., firefox and rustc/cargo upstream both ship their binaries built that way - they also tack on profile based optimizations for even more gains). Would be interesting to test whether for PBS we'd see benefits doing that as well?