From owner-svn-src-all@freebsd.org Wed Sep 19 16:08:33 2018 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 60F0C10A024E for ; Wed, 19 Sep 2018 16:08:33 +0000 (UTC) (envelope-from shawn.webb@hardenedbsd.org) Received: from mail-wr1-x443.google.com (mail-wr1-x443.google.com [IPv6:2a00:1450:4864:20::443]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id C97D487223 for ; Wed, 19 Sep 2018 16:08:32 +0000 (UTC) (envelope-from shawn.webb@hardenedbsd.org) Received: by mail-wr1-x443.google.com with SMTP id j8-v6so2664831wrw.5 for ; Wed, 19 Sep 2018 09:08:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=hardenedbsd.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=g5o8Cq4wfQGNa1A8BdvGQLXuyIZuTMiQucjTQtFEOUE=; b=Kc0qm1Yi0wax+xbXHFW2EBUAyFIDf/0xXROGPjgqaqt88WA9VniLHW4hxBbtz6ltJh AgH00jCm7TnZoOIyGjCTIyGPtg4c6beKt8Yt2SDMlujQJy+mwfYYN3hq590cXeDgc1RP mx2IhgGxjhcH5cV3LcZ7UBXqLLHVaq1zlv1ykd0hcrFHFqS0xyRHpYFn6rtnXhjkUhqK 64RFU2NZqaLHIUy3dW5YnLe3abjB+pY0YVO6QjZMf+3xkTSZ6oaaP94cVrNes/3ASxTo dl7zoKLSSR6a7JNHQfHPJQGPZG+DcUvGKhYmQ72YCTAhD5Vnd+/bjSp3+HBME6f7j6Xp zC6A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=g5o8Cq4wfQGNa1A8BdvGQLXuyIZuTMiQucjTQtFEOUE=; b=EJVDcRMiE1oejYdENShRRNyxyrMVdbbxmuaJFevJUjUIzHNVFxrd3M2YkEErLyyxxL FJZ1lJEj9awL4vq71Ix1TM3tr89HjGx+FxBZuYM/G/I6vzQ8xwHaiJTgslEcJ4PRLfo0 qb+Fgt7y6bfJ0075ailTkFeNt/dcBvDdqiYAxBSL41luLZKcy5SC1ikeVCEYHVfXDXNv wQcUbnVxvzZeqO2gvr6kah5qO079KcRKeMmyXJzrUoz7mX9vkYRqYA9i+1IcZSLs6HBJ cFhUMtMdS2vIRdeg5SGNfVksdKNLc7YY8YxFtobyA2Sr78pUVm7dpsj42eYXHPX5O+BX cvyg== X-Gm-Message-State: APzg51CorqqoLh0xBfrL0nvIymlHPEt72gKzKwvF7plZ/v37ccrG73fJ LrIT7ryycnHVJGewumGZKu1rlQ== X-Google-Smtp-Source: ANB0VdbjbGDwhQZdIkVS3PjhcGWXZfBYHIXQmaLISYaK0Zu5lnqFfhpK1Bbj85klNMNxTqeSKa96Eg== X-Received: by 2002:a5d:4990:: with SMTP id r16-v6mr29778056wrq.116.1537373311542; Wed, 19 Sep 2018 09:08:31 -0700 (PDT) Received: from mutt-hbsd ([193.19.118.171]) by smtp.gmail.com with ESMTPSA id y137-v6sm4411186wmc.3.2018.09.19.09.08.28 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 19 Sep 2018 09:08:30 -0700 (PDT) Date: Wed, 19 Sep 2018 12:08:19 -0400 From: Shawn Webb To: Mateusz Guzik Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r338802 - head/sys/vm Message-ID: <20180919160819.lfzrey3upzri4tll@mutt-hbsd> References: <201809191602.w8JG2Y0X046254@repo.freebsd.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="3huvumm73ebqbljo" Content-Disposition: inline In-Reply-To: <201809191602.w8JG2Y0X046254@repo.freebsd.org> X-Operating-System: FreeBSD mutt-hbsd 12.0-ALPHA5 FreeBSD 12.0-ALPHA5 X-PGP-Key: http://pgp.mit.edu/pks/lookup?op=vindex&search=0x6A84658F52456EEE User-Agent: NeoMutt/20180622 X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.27 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, 19 Sep 2018 16:08:33 -0000 --3huvumm73ebqbljo Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Sep 19, 2018 at 04:02:34PM +0000, Mateusz Guzik wrote: > Author: mjg > Date: Wed Sep 19 16:02:33 2018 > New Revision: 338802 > URL: https://svnweb.freebsd.org/changeset/base/338802 >=20 > Log: > vm: check for empty kstack cache before locking > =20 > The current cache logic checks the total number of stacks in the kernel, > which even on small boxes significantly exceeds the 128 limit (e.g. an > 8-way box with zfs has almost 800 stacks allocated). > =20 > Stacks are cached earlier for each main thread. > =20 > As a result the code is rarely executed, but when it is then (on boxes = like > the above) it always fails. Since there are no provisions made for NUMA= and > release time is approaching, just do a quick check to avoid acquiring t= he > lock. > =20 > Approved by: re (kib) >=20 > Modified: > head/sys/vm/vm_glue.c >=20 > Modified: head/sys/vm/vm_glue.c > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D > --- head/sys/vm/vm_glue.c Wed Sep 19 15:39:16 2018 (r338801) > +++ head/sys/vm/vm_glue.c Wed Sep 19 16:02:33 2018 (r338802) > @@ -327,7 +327,7 @@ vm_thread_new(struct thread *td, int pages) > else if (pages > KSTACK_MAX_PAGES) > pages =3D KSTACK_MAX_PAGES; > =20 > - if (pages =3D=3D kstack_pages) { > + if (pages =3D=3D kstack_pages && kstack_cache !=3D NULL) { > mtx_lock(&kstack_cache_mtx); > if (kstack_cache !=3D NULL) { > ks_ce =3D kstack_cache; Since kstack_cache is guaranteed not to be NULL, can the second conditional that checks for kstack_cache not being NULL be removed? Thanks, --=20 Shawn Webb Cofounder and Security Engineer HardenedBSD Tor-ified Signal: +1 443-546-8752 Tor+XMPP+OTR: lattera@is.a.hacker.sx GPG Key ID: 0x6A84658F52456EEE GPG Key Fingerprint: 2ABA B6BD EF6A F486 BE89 3D9E 6A84 658F 5245 6EEE --3huvumm73ebqbljo Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEKrq2ve9q9Ia+iT2eaoRlj1JFbu4FAluidG4ACgkQaoRlj1JF bu4f8xAAlfGz+6Wb3F6Hyip/fhypaiv/G2hAsEwV2pPvMDk0qIkqFxDrLE/shsgp UpjfCnkNFm9g/bVTxouPcDtuj5Tj1jLxBTlZcATw1lGvUTL30lUscT+bnIcw2ylz xwPhHpYdYjokhq91ju/faZ4IVTODhr3vDx9GyZVr7MDcRmSDQSWy4mW2+zoNCBg+ gF+I5lqpA4cN16tkLW+1nh+czdKsg8gn4k7JIp06DKwn5Zr1JeH5ZTnnAVYl27vR Pu8xtEcLHsMTDLw3VzGHiUdps5D9gfpy0GddqZvuFhYMcRiv87oX+78DCEFBoOQ5 IS0LfVb7ajacHzlGSq4ZbMb6rJOVAcfSSqHTdrxDL7TMIw1JG444HtGJPNeSd/nf tX1XRiHxvD86BgnF9sbXKX+wbrHC7ajvxXnEpHdZNXyKUhc5uPZYCcXgtsgMNkbm RAqJfP52d1WKbjnukWT3RdolwtzGViB60LD48xor9W0ImjQHHV22fa9l8CSh2mze 1SoCsnFw62g1Ulpgx3opzmvbHwHJ6OimvxFGBRmIFV7lfzGcdeeWRcbdEBa9xSSI 10FDVd9POeZ5ueKab8RGilQKcrnujzNsw0iSZfvwRCWqYNCjc90/zfZZ2nAkSyJ3 1Va8s8SC/UCJ/RpSw3leFkXeCf0ZioHs+7HB2HTrGcvyIdTFjRM= =G9fa -----END PGP SIGNATURE----- --3huvumm73ebqbljo--