From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by dcvr.yhbt.net (Postfix) with ESMTP id DC1821F9FE for ; Tue, 23 Feb 2021 02:26:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231573AbhBWC0i (ORCPT ); Mon, 22 Feb 2021 21:26:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43908 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231569AbhBWC02 (ORCPT ); Mon, 22 Feb 2021 21:26:28 -0500 Received: from mail-qk1-x730.google.com (mail-qk1-x730.google.com [IPv6:2607:f8b0:4864:20::730]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BC0BFC061794 for ; Mon, 22 Feb 2021 18:25:26 -0800 (PST) Received: by mail-qk1-x730.google.com with SMTP id f17so14868999qkl.5 for ; Mon, 22 Feb 2021 18:25:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ttaylorr-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=W7BAgY6QH8/c+NOhD4ioZpf2YtEHxcDQW5EvyimR7YQ=; b=jqjbjbqJgwuFYyIxonXcGfl47CRwhrnESVzd6eb0O0272I+V2XpZiMWNiAN2KUr6lU 2yiQwWOQnvjubf2KNv6wFEZxw70ndVNBRfYOo0U60pnP7Y99hRCD/OK3tswHmNVv0Np9 eZEz188Hr0iRSFRhpDyBWuSDyoLTEblLuqKrb3lIfbsO03bjED7vOKMvRB1/zZXSO2Q3 yTkCZJqhhafFMPfEmkDLwxyGbIwRwL8k8qTI2qsTYu60wrXv/lkijPUxncDI89ymo89N xrgqep4YDEGqzB+uXNVH673kDZKRA2YFboK5r9vleK4/IBK9bSlP7rfm/qKAGHlcOAiZ nmYA== 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; bh=W7BAgY6QH8/c+NOhD4ioZpf2YtEHxcDQW5EvyimR7YQ=; b=EF87d2oOFJog22pECcX138YslgtPOgxlTiZtWJUFzgcmYzW08DlJbac/6g+xV14fML FCDV/ZdVJPT4FYbHn+z1JNWxwj2g72TSPpIF3Ou/tlF45W2AEzCFv/UDKEUHQiDk31p6 AQ4bp8fFvqfTAAw46Icv1ZrfgVB3bVyVTBw5TQHXi77tbyEIH+R2RiQG+ixEFVUQG+zf /5J0lsZCewZLedFrokVDHXBCknkwq4glKja10PVDlUWa1if6B5m/5cKkzdq1CQBjjyob VlhSLEi7Jc84mfw8w+wHU87jyozCr3dZ7hgvRvVPudtZKJREyJkRVi+A1XysT7+PfMNx 8Vgg== X-Gm-Message-State: AOAM5319t1OF6AmSGkwSxD0Oto4Vt8qKeq6l5l+M2CzhsPaleo+V6Bx4 UHfuocdd99MUOxQaMRGntwOmZQHeCBYoG2jj X-Google-Smtp-Source: ABdhPJw9V9UBm9afFvaCnzthFFZ9wjB+WVKjY+F/UNHhoTs4zExrsKSaiWCSXh8ObZ798oKOWAk3Gw== X-Received: by 2002:a37:5088:: with SMTP id e130mr24533226qkb.321.1614047125620; Mon, 22 Feb 2021 18:25:25 -0800 (PST) Received: from localhost ([2605:9480:22e:ff10:29df:918f:599f:2c96]) by smtp.gmail.com with ESMTPSA id a206sm14042801qkc.7.2021.02.22.18.25.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 22 Feb 2021 18:25:25 -0800 (PST) Date: Mon, 22 Feb 2021 21:25:23 -0500 From: Taylor Blau To: git@vger.kernel.org Cc: peff@peff.net, dstolee@microsoft.com, gitster@pobox.com Subject: [PATCH v4 7/8] packfile: add kept-pack cache for find_kept_pack_entry() Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org From: Jeff King In a recent patch we added a function 'find_kept_pack_entry()' to look for an object only among kept packs. While this function avoids doing any lookup work in non-kept packs, it is still linear in the number of packs, since we have to traverse the linked list of packs once per object. Let's cache a reduced version of that list to save us time. Note that this cache will last the lifetime of the program. We could invalidate it on reprepare_packed_git(), but there's not much point in being rigorous here: - we might already fail to notice new .keep packs showing up after the program starts. We only reprepare_packed_git() when we fail to find an object. But adding a new pack won't cause that to happen. Somebody repacking could add a new pack and delete an old one, but most of the time we'd have a descriptor or mmap open to the old pack anyway, so we might not even notice. - in pack-objects we already cache the .keep state at startup, since 56dfeb6263 (pack-objects: compute local/ignore_pack_keep early, 2016-07-29). So this is just extending that concept further. - we don't have to worry about any packed_git being removed; we always keep the old structs around, even after reprepare_packed_git() We do defensively invalidate the cache in case the set of kept packs being asked for changes (e.g., only in-core kept packs were cached, but suddenly the caller also wants on-disk kept packs, too). In theory we could build all three caches and switch between them, but it's not necessary, since this patch (and series) never changes the set of kept packs that it wants to inspect from the cache. So that "optimization" is more about being defensive in the face of future changes than it is about asking for multiple kinds of kept packs in this patch. Here are p5303 results (as always, measured against the kernel): Test HEAD^ HEAD ----------------------------------------------------------------------------------------------- 5303.5: repack (1) 57.34(54.66+10.88) 56.98(54.36+10.98) -0.6% 5303.6: repack with kept (1) 57.38(54.83+10.49) 57.17(54.97+10.26) -0.4% 5303.11: repack (50) 71.70(88.99+4.74) 71.62(88.48+5.08) -0.1% 5303.12: repack with kept (50) 72.58(89.61+4.78) 71.56(88.80+4.59) -1.4% 5303.17: repack (1000) 217.19(491.72+14.25) 217.31(490.82+14.53) +0.1% 5303.18: repack with kept (1000) 246.12(520.07+14.93) 217.08(490.37+15.10) -11.8% and the --stdin-packs case, which scales a little bit better (although not by that much even at 1,000 packs): 5303.7: repack with --stdin-packs (1) 0.00(0.00+0.00) 0.00(0.00+0.00) = 5303.13: repack with --stdin-packs (50) 3.43(11.75+0.24) 3.43(11.69+0.30) +0.0% 5303.19: repack with --stdin-packs (1000) 130.50(307.15+7.66) 125.13(301.36+8.04) -4.1% Signed-off-by: Jeff King Signed-off-by: Taylor Blau --- object-store.h | 5 +++ packfile.c | 99 ++++++++++++++++++++++++++++---------------------- 2 files changed, 61 insertions(+), 43 deletions(-) diff --git a/object-store.h b/object-store.h index 541dab0858..ec32c23dcb 100644 --- a/object-store.h +++ b/object-store.h @@ -153,6 +153,11 @@ struct raw_object_store { /* A most-recently-used ordered version of the packed_git list. */ struct list_head packed_git_mru; + struct { + struct packed_git **packs; + unsigned flags; + } kept_pack_cache; + /* * A map of packfiles to packed_git structs for tracking which * packs have been loaded already. diff --git a/packfile.c b/packfile.c index 7f84f221ce..57d5b436fb 100644 --- a/packfile.c +++ b/packfile.c @@ -2042,10 +2042,7 @@ static int fill_pack_entry(const struct object_id *oid, return 1; } -static int find_one_pack_entry(struct repository *r, - const struct object_id *oid, - struct pack_entry *e, - int kept_only) +int find_pack_entry(struct repository *r, const struct object_id *oid, struct pack_entry *e) { struct list_head *pos; struct multi_pack_index *m; @@ -2055,49 +2052,63 @@ static int find_one_pack_entry(struct repository *r, return 0; for (m = r->objects->multi_pack_index; m; m = m->next) { - if (!fill_midx_entry(r, oid, e, m)) - continue; - - if (!kept_only) - return 1; - - if (((kept_only & ON_DISK_KEEP_PACKS) && e->p->pack_keep) || - ((kept_only & IN_CORE_KEEP_PACKS) && e->p->pack_keep_in_core)) + if (fill_midx_entry(r, oid, e, m)) return 1; } list_for_each(pos, &r->objects->packed_git_mru) { struct packed_git *p = list_entry(pos, struct packed_git, mru); - if (p->multi_pack_index && !kept_only) { - /* - * If this pack is covered by the MIDX, we'd have found - * the object already in the loop above if it was here, - * so don't bother looking. - * - * The exception is if we are looking only at kept - * packs. An object can be present in two packs covered - * by the MIDX, one kept and one not-kept. And as the - * MIDX points to only one copy of each object, it might - * have returned only the non-kept version above. We - * have to check again to be thorough. - */ - continue; - } - if (!kept_only || - (((kept_only & ON_DISK_KEEP_PACKS) && p->pack_keep) || - ((kept_only & IN_CORE_KEEP_PACKS) && p->pack_keep_in_core))) { - if (fill_pack_entry(oid, e, p)) { - list_move(&p->mru, &r->objects->packed_git_mru); - return 1; - } + if (!p->multi_pack_index && fill_pack_entry(oid, e, p)) { + list_move(&p->mru, &r->objects->packed_git_mru); + return 1; } } return 0; } -int find_pack_entry(struct repository *r, const struct object_id *oid, struct pack_entry *e) +static void maybe_invalidate_kept_pack_cache(struct repository *r, + unsigned flags) { - return find_one_pack_entry(r, oid, e, 0); + if (!r->objects->kept_pack_cache.packs) + return; + if (r->objects->kept_pack_cache.flags == flags) + return; + FREE_AND_NULL(r->objects->kept_pack_cache.packs); + r->objects->kept_pack_cache.flags = 0; +} + +static struct packed_git **kept_pack_cache(struct repository *r, unsigned flags) +{ + maybe_invalidate_kept_pack_cache(r, flags); + + if (!r->objects->kept_pack_cache.packs) { + struct packed_git **packs = NULL; + size_t nr = 0, alloc = 0; + struct packed_git *p; + + /* + * We want "all" packs here, because we need to cover ones that + * are used by a midx, as well. We need to look in every one of + * them (instead of the midx itself) to cover duplicates. It's + * possible that an object is found in two packs that the midx + * covers, one kept and one not kept, but the midx returns only + * the non-kept version. + */ + for (p = get_all_packs(r); p; p = p->next) { + if ((p->pack_keep && (flags & ON_DISK_KEEP_PACKS)) || + (p->pack_keep_in_core && (flags & IN_CORE_KEEP_PACKS))) { + ALLOC_GROW(packs, nr + 1, alloc); + packs[nr++] = p; + } + } + ALLOC_GROW(packs, nr + 1, alloc); + packs[nr] = NULL; + + r->objects->kept_pack_cache.packs = packs; + r->objects->kept_pack_cache.flags = flags; + } + + return r->objects->kept_pack_cache.packs; } int find_kept_pack_entry(struct repository *r, @@ -2105,13 +2116,15 @@ int find_kept_pack_entry(struct repository *r, unsigned flags, struct pack_entry *e) { - /* - * Load all packs, including midx packs, since our "kept" strategy - * relies on that. We're relying on the side effect of it setting up - * r->objects->packed_git, which is a little ugly. - */ - get_all_packs(r); - return find_one_pack_entry(r, oid, e, flags); + struct packed_git **cache; + + for (cache = kept_pack_cache(r, flags); *cache; cache++) { + struct packed_git *p = *cache; + if (fill_pack_entry(oid, e, p)) + return 1; + } + + return 0; } int has_object_pack(const struct object_id *oid) -- 2.30.0.667.g81c0cbc6fd