Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1225039
| Path | csiph.com!eternal-september.org!feeder.eternal-september.org!aioe.org!bofh.it!news.nic.it!robomod |
|---|---|
| From | Aleksa Sarai <cyphar@cyphar.com> |
| Newsgroups | linux.kernel |
| Subject | Optimising USERNS mapping translation. |
| Date | Tue, 15 Sep 2015 14:40:01 +0200 |
| Message-ID | <q8XGF-4Ub-13@gated-at.bofh.it> (permalink) |
| X-Original-To | "Eric W. Biederman" <ebiederm@xmission.com> |
| X-Google-Dkim-Signature | v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:date:message-id:subject:from:to:cc :content-type; bh=gvZVz72q1DNrYC92gYHA4rw7OJA1Jm6NFsyFqW9FPMs=; b=FAmyad6AbOAjRmO13VoxwpKHAH7WcB3oCFgkZWlIBoQxSsOpdrUUQGs1M+sg3GjBSd jspnNdJ9+vVBOKSGY21UsfweFuQbWd+wUQXkvDKQzaq7Grrqqnz2IDvmkcxAKtHsToY7 IShWkTxoHT66JHSdmSBS/OunFgLPCjAtTd2xGd7G/su5KBFE0FSaLlFaEOatkfFMuufb jRwf5h2ILb4oaeOsEup7aNjFlFJLPpStAttbpp0qxU/wFyTEUQgoWd4eVZ+6ymUcqUn1 KGX1CqNtepeV8FLHpXO7ur3m1jNA6o97zLfv3F+keam7MiQMI/H/MLUOeXi9qdgH9dsl WiNw== |
| X-Gm-Message-State | ALoCoQlxk4V402V9oKnRfy49xtCaizANw/t2XD9WWDJAehYh62drEVWd4gwFPVj46B5nuTuZztnR |
| MIME-Version | 1.0 |
| X-Received | by 10.50.124.4 with SMTP id me4mr5480296igb.34.1442320545502; Tue, 15 Sep 2015 05:35:45 -0700 (PDT) |
| X-Originating-IP | [122.106.150.15] |
| Content-Type | text/plain; charset=UTF-8 |
| Sender | robomod@news.nic.it |
| List-ID | <linux-kernel.vger.kernel.org> |
| X-Mailing-List | linux-kernel@vger.kernel.org |
| Approved | robomod@news.nic.it |
| Lines | 20 |
| Organization | linux.* mail to news gateway |
| X-Original-Cc | Andy Lutomirski <luto@kernel.org>, Al Viro <viro@zeniv.linux.org.uk>, Christoph Lameter <cl@linux.com>, Kees Cook <keescook@chromium.org>, linux-kernel@vger.kernel.org |
| X-Original-Date | Tue, 15 Sep 2015 22:35:45 +1000 |
| X-Original-Message-ID | <CAOviyaiRY5WA+kfSyaKKL7nJCeLOCgf5cCenbiRDHoO+M1NcAg@mail.gmail.com> |
| X-Original-Sender | linux-kernel-owner@vger.kernel.org |
| Xref | csiph.com linux.kernel:1225039 |
Show key headers only | View raw
Hi, I'm wondering if there's a reason that we do a linear search for the mapping translations between kuid_t and uid_t. Surely something like a radix trie would (potentially) allow for better storage and lookup? Is the whole "an extent fits in a cache line" a good enough optimisation that it would be pointless to use a better structure? Also, is there a good reason why we have UID_GID_MAP_MAX_EXTENTS = 5 (other than the one cache line thing)? Surely it's not more efficient to have to create a bunch of nested namespaces in order to have more than 5 extents? -- Aleksa Sarai (cyphar) www.cyphar.com -- 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/
Back to linux.kernel | Previous | Next — Next in thread | Find similar | Unroll thread
Optimising USERNS mapping translation. Aleksa Sarai <cyphar@cyphar.com> - 2015-09-15 14:40 +0200 Re: Optimising USERNS mapping translation. "Eric W. Biederman" <ebiederm@xmission.com> - 2015-09-15 16:10 +0200
csiph-web