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Resent-From: Maxim Cournoyer Original-Sender: "Debbugs-submit" Resent-CC: guix-patches@gnu.org Resent-Date: Sun, 31 Oct 2021 20:52:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 51427 X-GNU-PR-Package: guix-patches X-GNU-PR-Keywords: patch To: Ludovic =?UTF-8?Q?Court=C3=A8s?= Cc: 51427@debbugs.gnu.org, Liliana Marie Prikler Received: via spool by 51427-submit@debbugs.gnu.org id=B51427.163571350513640 (code B ref 51427); Sun, 31 Oct 2021 20:52:01 +0000 Received: (at 51427) by debbugs.gnu.org; 31 Oct 2021 20:51:45 +0000 Received: from localhost ([127.0.0.1]:33175 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1mhHnt-0003Xw-H4 for submit@debbugs.gnu.org; Sun, 31 Oct 2021 16:51:45 -0400 Received: from mail-qk1-f170.google.com ([209.85.222.170]:33313) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1mhHnr-0003Xh-CH for 51427@debbugs.gnu.org; Sun, 31 Oct 2021 16:51:43 -0400 Received: by mail-qk1-f170.google.com with SMTP id a132so13747627qkg.0 for <51427@debbugs.gnu.org>; Sun, 31 Oct 2021 13:51:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:references:date:in-reply-to:message-id :user-agent:mime-version:content-transfer-encoding; bh=Ko6H/BV6WE/WlkVC1GO1AiW9LXIPfe5A07BwQ9NXRIE=; b=QATU9+qXOR/E20yiHOkIn0t3QCv2cUfYpiRmTr4WAjd+fyhgebK6MRi2x90ycNOeGE GvVzOjrT/hivkjEth4UJbqOnIZbmBwjq2SrugHngF0xgI32UNaN4p9Pf8PByHPn1GN7L E13rpqiqSEeHDlo7P50mFMaGydgJcCut58Xw69jjaTOz2GXLWwQmTX8prGchXGGZHuzk m3p/VfhAkR2wlb2hxoNTKIuaOWUx7SFAXcr2xChHtHVPL+9C/D8J9chrzsnVtjIRdqp5 VamVl4A0fShRDkFv2N8qD3laBp+q4sa4GJ0Hk+B6NDDZ6baqGoFm1UwwtORQUESLCmxM R8dw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:references:date:in-reply-to :message-id:user-agent:mime-version:content-transfer-encoding; bh=Ko6H/BV6WE/WlkVC1GO1AiW9LXIPfe5A07BwQ9NXRIE=; b=er9eHTwmhwgr7Ln6Rz6aRyHocCZ+uMfuPa5kr6ZEzY3bRH7IoS1YPl22aEJcyDkMfV v9oGAXkBRAWxsV7aB8F6pQwEyZGRfSd6bJz3Np/pxisrUpb7JL+Xaw7mI+1vP5zUz4xj OGthbmz9YR9ZsmcxmbDL67L39uQf/Z6xT9cONG+ReYTmPDUENecWYyKPn1ib8DSRUJgE /me3qSKhg6oIgmut53eTR+nCB5juyTy/R8RZ6ZSuF+XwlbhUw/FziTLy2VY8Fd+1AuFN mXEoAE/Yc/pm5JkpWtjQtmwALKBgWMI71HtbF0GGpD6GFBniByKPmGBhD9o/BSWfSN4O HKnw== X-Gm-Message-State: AOAM531QKBJkc7ZZuwE0vMmbsOlaeHylo50MS3wpBsTNWMVVtN6VA2m7 rP6TRmVicm4/JNQA7iValDU2PN+XM6k= X-Google-Smtp-Source: ABdhPJxb5+AXAuk/CspT199mBdNuTTl2Sh4pIu578vkUnE2uI+oOEDxUgWO9YyD2dMnm8lniO3QbBg== X-Received: by 2002:a05:620a:178b:: with SMTP id ay11mr20500299qkb.287.1635713497455; Sun, 31 Oct 2021 13:51:37 -0700 (PDT) Received: from hurd (dsl-153-210.b2b2c.ca. [66.158.153.210]) by smtp.gmail.com with ESMTPSA id e18sm6132720qtw.12.2021.10.31.13.51.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 31 Oct 2021 13:51:37 -0700 (PDT) From: Maxim Cournoyer References: <20211027034918.4591-1-maxim.cournoyer@gmail.com> <87o8795j61.fsf@gnu.org> <5c2dd60acfaa7d74b7554babb3e223bc855bac8a.camel@gmail.com> <87h7cxp9tl.fsf@gnu.org> Date: Sun, 31 Oct 2021 16:51:36 -0400 In-Reply-To: <87h7cxp9tl.fsf@gnu.org> ("Ludovic =?UTF-8?Q?Court=C3=A8s?="'s message of "Sun, 31 Oct 2021 15:07:02 +0100") Message-ID: <87sfwg7w9z.fsf@gmail.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: guix-patches@gnu.org List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guix-patches-bounces+larch=yhetil.org@gnu.org Sender: "Guix-patches" X-Migadu-Flow: FLOW_IN ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=yhetil.org; s=key1; t=1635713583; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding:resent-cc: resent-from:resent-sender:resent-message-id:in-reply-to:in-reply-to: references:references:list-id:list-help:list-unsubscribe: list-subscribe:list-post:dkim-signature; bh=Ko6H/BV6WE/WlkVC1GO1AiW9LXIPfe5A07BwQ9NXRIE=; b=SBayDf8xS5ltaEPAHsl4OO+ufspO66Yn1RTX7cAfW2ifdmlou/czU+oBZU1AqNlVZ9OPyF LvWNnKWN05KyjQy9tLfK3J+k3127ZmkYUY/4x5WZjdIIDWEvqp8dFohg5dVvHrUQja5aM6 zzv2vpaDxssCOe+IfHOmTSO1CqpNfEyuv3jqxM3rUwWG7fxinz6molVMfIQUuRCIzSHwD3 Sv8HLYGVibSA710/CC8Kwpr1K281rB8G77JX/3ca+n1olCqVLOB4Hy75CF0/1Gg92+CG6h GjKimi8MXeyaSojYJ0y46DS7hQGYLr8FqUYdctsEptBtXhb73sFDH1AEx4x+9g== ARC-Seal: i=1; s=key1; d=yhetil.org; t=1635713583; a=rsa-sha256; cv=none; b=dVc31fIAM6kkRmGDEIPPSPxeMLCGslLAVrXM11v4VNp48LWI0YEuEg0ri/4zcxSXfOzxwG v6PnPg6h2+2T+47zOLMo/x+kDCi6HrcKmzr1YXzlk6X+vebO/sbN/K1ggdyfmUKeikFvPk jAmL1y+vll61mTpr8RvYwrhB+li4/gvzGXMzdTuLJz56D/ng6Ia+ZBKvQCNE6N2EVEOJER L6n11qYvJDduYG/Td4KcfEEq1gyJ3Dt8NEfZUTLNxU8ZI0rLtf7JgfXSmcwrLihsrPC46N VrceKQeRub6/yt0tQIG8fm/D42ZqcNaAd6UXiYtD2wARWUEprmpW2wmMi98VsA== ARC-Authentication-Results: i=1; aspmx1.migadu.com; dkim=fail ("headers rsa verify failed") header.d=gmail.com header.s=20210112 header.b=QATU9+qX; dmarc=fail reason="SPF not aligned (relaxed)" header.from=gmail.com (policy=none); spf=pass (aspmx1.migadu.com: domain of guix-patches-bounces@gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=guix-patches-bounces@gnu.org X-Migadu-Spam-Score: 0.18 Authentication-Results: aspmx1.migadu.com; dkim=fail ("headers rsa verify failed") header.d=gmail.com header.s=20210112 header.b=QATU9+qX; dmarc=fail reason="SPF not aligned (relaxed)" header.from=gmail.com (policy=none); spf=pass (aspmx1.migadu.com: domain of guix-patches-bounces@gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=guix-patches-bounces@gnu.org X-Migadu-Queue-Id: E730910654 X-Spam-Score: 0.18 X-Migadu-Scanner: scn0.migadu.com X-TUID: Xd+p6RSyHHhq Hi, Ludovic Court=C3=A8s writes: > Hi, > > Liliana Marie Prikler skribis: > >> Am Donnerstag, den 28.10.2021, 16:16 +0200 schrieb Ludovic Court=C3=A8s: >>> Hi, >>>=20 >>> Maxim Cournoyer skribis: >>>=20 >>> > Deleting unused links can be a very costly operation, especially on >>> > rotative hard drives. As removing single store items is often used >>> > for experimentation rather than for cleaning purposes, this change >>> > allows it to run without the links cleanup. >>> >=20 >>> > * nix/libstore/gc.cc (LocalStore::collectGarbage): Do not clean up >>> > links when >>> > the specified action is GCOptions::gcDeleteSpecific. >>> > --- >>> > nix/libstore/gc.cc | 2 +- >>> > 1 file changed, 1 insertion(+), 1 deletion(-) >>> >=20 >>> > diff --git a/nix/libstore/gc.cc b/nix/libstore/gc.cc >>> > index e1d0765154..7d872d8cc1 100644 >>> > --- a/nix/libstore/gc.cc >>> > +++ b/nix/libstore/gc.cc >>> > @@ -771,7 +771,7 @@ void LocalStore::collectGarbage(const GCOptions >>> > & options, GCResults & results) >>> > deleteGarbage(state, state.trashDir); >>> >=20=20 >>> > /* Clean up the links directory. */ >>> > - if (options.action =3D=3D GCOptions::gcDeleteDead || >>> > options.action =3D=3D GCOptions::gcDeleteSpecific) { >>> > + if (options.action =3D=3D GCOptions::gcDeleteDead) { >>>=20 >>> I believe the effect is that =E2=80=98guix gc -D /gnu/store/=E2=80=A6-d= isk-image=E2=80=99 >>> would remove nothing: /gnu/store/.links would still contain a copy of >>> that big disk image, so as a result, you=E2=80=99ve freed zero bytes. >>>=20 >>> Am I right? >> I think that might be the point. As Maxim said, single items are >> (likely) not removed for cleaning purposes, so freeing the disk image >> has little effect. > > What do you mean? When doing VM testing, I regularly do =E2=80=98guix gc= -D > /gnu/store/=E2=80=A6-disk-image=E2=80=99 precisely to save space. Fortun= ately it does > have the intended effect of freeing a bunch of GiBs. > >> Plus, you could invoke it like >> >> guix gc -D dead-item dead-item live-item dead-item >> >> It would fail at live-item and then not continue to free the links of >> the two dead items prior. > > Yes, and that=E2=80=99s annoying, but it=E2=80=99s unrelated. :-) > >> So there's a few things we could do here: >> >> 1. simply fail and have the user deal with it (including the option of >> doing a normal `guix gc' or `guix gc -C 1') >> 2. remember which paths were live and dead and always clean up the >> links, only reporting errors afterwards >> 3. add an option to explicitly check the .links directory (which >> defaults to true for the current things, but could also be used to >> clean links after a liveness check or after a do-nothing `guix gc -F'). >> 4. ... > > You seem to be proposing to remove =E2=80=98-D=E2=80=99 altogether. I ag= ree it has the > shortcomings you write, but I think it=E2=80=99s occasionally useful > nonetheless. > > My proposal would be either the status quo, or removing just the one > link that matters from /gnu/store/.links upon =E2=80=98-D=E2=80=99. The second proposal makes sense. I didn't care about freeing space, as my use case was getting around corrupting an item in my store due to https://issues.guix.gnu.org/51400, which the patch proposed here allowed me to do without wasting hours of cleaning up links (nearly 1 GiB of store on spinning drives). Thanks, Maxim