From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 40489 invoked by alias); 14 Jun 2018 13:50:03 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 40474 invoked by uid 89); 14 Jun 2018 13:50:03 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=0.1 required=5.0 tests=AWL,BAYES_00,KAM_LAZY_DOMAIN_SECURITY,KAM_LIVE autolearn=no version=3.3.2 spammy=Hx-languages-length:955 X-HELO: atrey.karlin.mff.cuni.cz Date: Thu, 14 Jun 2018 13:50:00 -0000 From: Pavel Machek To: Mathieu Desnoyers Cc: Florian Weimer , carlos , Peter Zijlstra , "Paul E. McKenney" , Boqun Feng , Thomas Gleixner , linux-kernel , libc-alpha Subject: Re: Restartable Sequences system call merged into Linux Message-ID: <20180614134959.GA4084@amd> References: <1084280721.10859.1528746558696.JavaMail.zimbra@efficios.com> <31fc101a-295b-067b-1a82-7e9e509fc92f@redhat.com> <305409897.10888.1528747473727.JavaMail.zimbra@efficios.com> <091061df-3482-8762-30e4-feaf3417be11@redhat.com> <417742741.11550.1528821084084.JavaMail.zimbra@efficios.com> <20180614122759.GB8798@amd> <894222691.12973.1528981314012.JavaMail.zimbra@efficios.com> <20180614132557.GA15201@amd> <956816108.13001.1528983496098.JavaMail.zimbra@efficios.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="0OAP2g/MAC+5xKAE" Content-Disposition: inline In-Reply-To: <956816108.13001.1528983496098.JavaMail.zimbra@efficios.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-SW-Source: 2018-06/txt/msg00406.txt.bz2 --0OAP2g/MAC+5xKAE Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Content-length: 935 Hi! > >> - rseq_preempt(): on preemption, the scheduler sets the TIF_NOTIFY_RES= UME thread > >> flag, so rseq_handle_notify_resume() can check whether it's in a rse= q critical > >> section when returning to user-space, > >> - rseq_signal_deliver(): on signal delivery, rseq_handle_notify_resume= () checks > >> whether it's in a rseq critical section, > >> - rseq_migrate: on migration, the scheduler sets TIF_NOTIFY_RESUME as = well, > >=20 > > Yes, this is not likely to be noticeable. > >=20 > > But the proposal wanted to add a syscall to thread creation, right? > > And I believe that may be noticeable. >=20 > Fair point! Do we have a standard benchmark that would stress this ? Web server performance benchmarks basically test clone() performance in many cases. Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --0OAP2g/MAC+5xKAE Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature Content-length: 181 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlsicocACgkQMOfwapXb+vIPEACgs1vuWmzWdUvcvy34IY9uH7Rv aykAniy6xAOHIGIG+3DTiZI+Z+spFshk =CzEe -----END PGP SIGNATURE----- --0OAP2g/MAC+5xKAE--