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([2607:fb90:b2b2:fc25:25fc:8f78:cb92:220a]) by smtp.gmail.com with ESMTPSA id c66sm5487635pfb.25.2019.10.23.11.31.42 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 23 Oct 2019 11:31:42 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable From: Enji Cooper Mime-Version: 1.0 (1.0) Subject: Re: svn commit: r353937 - in head/share: man/man5 mk Date: Wed, 23 Oct 2019 11:31:41 -0700 Message-Id: <2B855247-5097-442D-8D4A-77D68D2F6186@gmail.com> References: <201910231702.x9NH2jQv045130@repo.freebsd.org> Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org In-Reply-To: <201910231702.x9NH2jQv045130@repo.freebsd.org> To: Dimitry Andric X-Mailer: iPhone Mail (17A878) X-Rspamd-Queue-Id: 46yzVT2xW0z4Wml X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org; dkim=pass header.d=gmail.com header.s=20161025 header.b=gRsAL289; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (mx1.freebsd.org: domain of yaneurabeya@gmail.com designates 2607:f8b0:4864:20::443 as permitted sender) smtp.mailfrom=yaneurabeya@gmail.com X-Spamd-Result: default: False [-2.50 / 15.00]; RCVD_VIA_SMTP_AUTH(0.00)[]; TO_DN_SOME(0.00)[]; R_SPF_ALLOW(-0.20)[+ip6:2607:f8b0:4000::/36]; FREEMAIL_FROM(0.00)[gmail.com]; MV_CASE(0.50)[]; RCVD_COUNT_THREE(0.00)[3]; DKIM_TRACE(0.00)[gmail.com:+]; DMARC_POLICY_ALLOW(-0.50)[gmail.com,none]; FROM_EQ_ENVFROM(0.00)[]; IP_SCORE(0.00)[ip: (-0.68), ipnet: 2607:f8b0::/32(-2.42), asn: 15169(-2.06), country: US(-0.05)]; MIME_TRACE(0.00)[0:+]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:15169, ipnet:2607:f8b0::/32, country:US]; MID_RHS_MATCH_FROM(0.00)[]; DWL_DNSWL_NONE(0.00)[gmail.com.dwl.dnswl.org : 127.0.5.0]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; R_DKIM_ALLOW(-0.20)[gmail.com:s=20161025]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[4]; TO_MATCH_ENVRCPT_ALL(0.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_GOOD(-0.10)[text/plain]; IP_SCORE_FREEMAIL(0.00)[]; RCVD_IN_DNSWL_NONE(0.00)[3.4.4.0.0.0.0.0.0.0.0.0.0.0.0.0.0.2.0.0.4.6.8.4.0.b.8.f.7.0.6.2.list.dnswl.org : 127.0.5.0]; RCVD_TLS_ALL(0.00)[] X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 23 Oct 2019 18:31:46 -0000 > On Oct 23, 2019, at 10:02, Dimitry Andric wrote: >=20 > =EF=BB=BFAuthor: dim > Date: Wed Oct 23 17:02:45 2019 > New Revision: 353937 > URL: https://svnweb.freebsd.org/changeset/base/353937 >=20 > Log: > Build toolchain components as dynamically linked executables by default >=20 > Summary: > Historically, we have built toolchain components such as cc, ld, etc as > statically linked executables. One of the reasons being that you could > sometimes save yourself from botched upgrades, by e.g. recompiling a > "known good" libc and reinstalling it. >=20 > In this day and age, we have boot environments, virtual machine > snapshots, cloud backups, and other much more reliable methods to > restore systems to working order. So I think the time is ripe to flip > this default, and link the toolchain components dynamically, just like > almost all other executables on FreeBSD. >=20 > Maybe at some point they can even become PIE executables by default! :) There might be a different reason for this being the case than the one posed= . Using dynamic binaries instead of static binaries might actually regress per= formance in a way you don=E2=80=99t expect, depending on -j values, etc. Sta= tic binaries avoid the dynamic linker, which (obviously) results in a perf h= it at scale, at the potential cost of the in-memory image. Static binaries c= ould also better optimize away less optimal code paths, which could result i= n worse performing code. Did you calculate the perf trade offs for the static binaries at low -j vs h= igh -j, system and user time, etc? Cheers, -Enji PS Thank you for keeping the SHARED_TOOLCHAIN option.=