Deutsch English Français Italiano |
<jwvmsnrf8wn.fsf-monnier+comp.arch@gnu.org> View for Bookmarking (what is this?) Look up another Usenet article |
Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Stefan Monnier <monnier@iro.umontreal.ca> Newsgroups: comp.arch Subject: Critical word first (was: Privilege Levels Below User) Date: Tue, 11 Jun 2024 17:51:14 -0400 Organization: A noiseless patient Spider Lines: 15 Message-ID: <jwvmsnrf8wn.fsf-monnier+comp.arch@gnu.org> References: <jai66jd4ih4ejmek0abnl4gvg5td4obsqg@4ax.com> <h0ib6j576v8o37qu1ojrsmeb5o88f29upe@4ax.com> <2024Jun9.185245@mips.complang.tuwien.ac.at> <38ob6jl9sl3ceb0qugaf26cbv8lk7hmdil@4ax.com> <2024Jun10.091648@mips.complang.tuwien.ac.at> <o32f6jlq2qpi9s1u8giq521vv40uqrkiod@4ax.com> <3a691dbdc80ebcc98d69c3a234f4135b@www.novabbs.org> <k58h6jlvp9rl13br6v1t24t47t4t2brfiv@4ax.com> <5a27391589243e11b610b14c3015ec09@www.novabbs.org> MIME-Version: 1.0 Content-Type: text/plain Injection-Date: Tue, 11 Jun 2024 23:51:14 +0200 (CEST) Injection-Info: dont-email.me; posting-host="adecb8f45b089a8dec176645b14c32be"; logging-data="1314347"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19DBjF8r6KSuGfmEfLxHKUiO/hbCYh2vgw=" User-Agent: Gnus/5.13 (Gnus v5.13) Cancel-Lock: sha1:6wCFJXZsqH+eNt29uwRWq/fh/4s= sha1:N/Luj+UfM70kDqW8P/3Hn2K4ocs= Bytes: 1828 >> [...] is performed which *completely bypasses* the cache; [...] > Yes, critical word first. How important is this nowadays? From what I can tell, the bandwidth-time of transferring a whole cache line is extremely short compared to the latency to the first word, so I assumed that whether the critical word is send first or not wouldn't make much of a difference. Is my intuition wrong? Or is it simply that the difference is small but the cost is even smaller? Stefan