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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A9636C433EF for ; Tue, 5 Oct 2021 18:42:16 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0B715611CA for ; Tue, 5 Oct 2021 18:42:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 0B715611CA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ucw.cz Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 76C936B006C; Tue, 5 Oct 2021 14:42:15 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 71CE16B0071; Tue, 5 Oct 2021 14:42:15 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 60B136B0073; Tue, 5 Oct 2021 14:42:15 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0071.hostedemail.com [216.40.44.71]) by kanga.kvack.org (Postfix) with ESMTP id 539E46B006C for ; Tue, 5 Oct 2021 14:42:15 -0400 (EDT) Received: from smtpin37.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 090E582499A8 for ; Tue, 5 Oct 2021 18:42:15 +0000 (UTC) X-FDA: 78663253830.37.6936FF1 Received: from jabberwock.ucw.cz (jabberwock.ucw.cz [46.255.230.98]) by imf28.hostedemail.com (Postfix) with ESMTP id 7FA589001355 for ; Tue, 5 Oct 2021 18:42:14 +0000 (UTC) Received: by jabberwock.ucw.cz (Postfix, from userid 1017) id CF8431C0B80; Tue, 5 Oct 2021 20:42:11 +0200 (CEST) Date: Tue, 5 Oct 2021 20:42:11 +0200 From: Pavel Machek To: Suren Baghdasaryan Cc: akpm@linux-foundation.org, ccross@google.com, sumit.semwal@linaro.org, mhocko@suse.com, dave.hansen@intel.com, keescook@chromium.org, willy@infradead.org, kirill.shutemov@linux.intel.com, vbabka@suse.cz, hannes@cmpxchg.org, corbet@lwn.net, viro@zeniv.linux.org.uk, rdunlap@infradead.org, kaleshsingh@google.com, peterx@redhat.com, rppt@kernel.org, peterz@infradead.org, catalin.marinas@arm.com, vincenzo.frascino@arm.com, chinwen.chang@mediatek.com, axelrasmussen@google.com, aarcange@redhat.com, jannh@google.com, apopple@nvidia.com, jhubbard@nvidia.com, yuzhao@google.com, will@kernel.org, fenghua.yu@intel.com, thunder.leizhen@huawei.com, hughd@google.com, feng.tang@intel.com, jgg@ziepe.ca, guro@fb.com, tglx@linutronix.de, krisman@collabora.com, chris.hyser@oracle.com, pcc@google.com, ebiederm@xmission.com, axboe@kernel.dk, legion@kernel.org, eb@emlix.com, gorcunov@gmail.com, songmuchun@bytedance.com, viresh.kumar@linaro.org, thomascedeno@google.com, sashal@kernel.org, cxfcosmos@gmail.com, linux@rasmusvillemoes.dk, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, kernel-team@android.com Subject: Re: [PATCH v10 3/3] mm: add anonymous vma name refcounting Message-ID: <20211005184211.GA19804@duo.ucw.cz> References: <20211001205657.815551-1-surenb@google.com> <20211001205657.815551-3-surenb@google.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="OXfL5xGRrasGEqWY" Content-Disposition: inline In-Reply-To: <20211001205657.815551-3-surenb@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Rspamd-Queue-Id: 7FA589001355 X-Stat-Signature: n3pw6zzsbi4hfnfex84xd3g5puoyuxq4 Authentication-Results: imf28.hostedemail.com; dkim=none; dmarc=none; spf=none (imf28.hostedemail.com: domain of pavel@ucw.cz has no SPF policy when checking 46.255.230.98) smtp.mailfrom=pavel@ucw.cz X-Rspamd-Server: rspam06 X-HE-Tag: 1633459334-871485 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: --OXfL5xGRrasGEqWY Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri 2021-10-01 13:56:57, Suren Baghdasaryan wrote: > While forking a process with high number (64K) of named anonymous vmas the > overhead caused by strdup() is noticeable. Experiments with ARM64 Android I still believe you should simply use numbers and do the numbers->strings mapping in userspace. We should not need to optimize strdups in kernel... Best regards, Pavel --=20 http://www.livejournal.com/~pavelmachek --OXfL5xGRrasGEqWY Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iF0EABECAB0WIQRPfPO7r0eAhk010v0w5/Bqldv68gUCYVycgwAKCRAw5/Bqldv6 8ldxAJ42e5af3RsjK7JWO3GXzU8KdW/AEACePslf94VkISUgVCg0Ezu8/5NcUbg= =46UI -----END PGP SIGNATURE----- --OXfL5xGRrasGEqWY--