From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Turner Subject: [PATCH v6 02/19] read-cache: allow to keep mmap'd memory after reading Date: Wed, 27 Apr 2016 16:04:24 -0400 Message-ID: <1461787481-877-3-git-send-email-dturner@twopensource.com> References: <1461787481-877-1-git-send-email-dturner@twopensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: David Turner To: git@vger.kernel.org, pclouds@gmail.com X-From: git-owner@vger.kernel.org Wed Apr 27 22:06:58 2016 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1avVjb-0003mY-Qe for gcvg-git-2@plane.gmane.org; Wed, 27 Apr 2016 22:06:56 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753721AbcD0UGk convert rfc822-to-quoted-printable (ORCPT ); Wed, 27 Apr 2016 16:06:40 -0400 Received: from mail-qg0-f52.google.com ([209.85.192.52]:36100 "EHLO mail-qg0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753065AbcD0UFM (ORCPT ); Wed, 27 Apr 2016 16:05:12 -0400 Received: by mail-qg0-f52.google.com with SMTP id d90so21813551qgd.3 for ; Wed, 27 Apr 2016 13:05:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=twopensource-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=qWsQqUT0TEbkQssEa8cmGJohJfXp0Da97rhFbruFwGg=; b=NCEtFnwYQE/NMUV1FGpj3Gcz/xP/cj9g9XwFsHbIq4rnWjcvWaTqxiPms4RJrkmQnh aJx0SrslEQ1OAVpw67/VgD+vgBkDu7+4l/MPQNC3rNHB5lRmPuhxVPDflVzjovxRhvBe POzjWuzymfM/vjbiHGfzx9dt9Mzze9Iny/P4cYBYt5hxxHXp6mFDed1NBx7i0LvjBI+j aQ9IGYbwSghgy4XzyQ/X6Omr4A77uyj2VX8i6tOLQtlLGtIxhJbBoe49Uc8vw92QjDUb Ws1BcYwBsbDcyzbFYIVWoAPyYLmuc7cgBaNAPxnl8w9jaWRJlUHT+say9OfrcN9Ca79h BWgA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=qWsQqUT0TEbkQssEa8cmGJohJfXp0Da97rhFbruFwGg=; b=M/GZ/Up4d8xH2ebCzklNTjY19zYAtuwT/dwoEvvNLi8e9teaxhE0ip7LqyMayn5dIA rAoGMcz6BMcSrRHgtjzlwvB0ZJ5UJydkvgdvfSVLllkcILPEkcl8vD8SilFcrwTR0ztH 1a+aLhfn7dWDP3MYAzf/+KwccpkdlR/JnKk2vaTPR1kocYisj4NOb3IHSnG4ROXwUKDl +0eGllv/T4wzThcU27TfeVs6qeDWFRmxzOWVfdB95TcQP5T4FXAacShmCiiXz7DqxRfw sGiwUUSfWhv3Beh6ce+9XetVIacOakPJ8+pojHPLfikoQ9jaFnNsSRn+FBYKEUp9Q/IX Wv+Q== X-Gm-Message-State: AOPr4FVWGhys2cbUo38VIZ6qVMs0Wrrz5dvLA2ZBt80I8b7mwQuqRjb06FenBp+jM6GjjQ== X-Received: by 10.140.100.173 with SMTP id s42mr10036551qge.19.1461787511253; Wed, 27 Apr 2016 13:05:11 -0700 (PDT) Received: from ubuntu.twitter.biz ([192.133.79.145]) by smtp.gmail.com with ESMTPSA id r124sm1700085qhr.48.2016.04.27.13.05.09 (version=TLSv1/SSLv3 cipher=OTHER); Wed, 27 Apr 2016 13:05:10 -0700 (PDT) X-Mailer: git-send-email 2.4.2.767.g62658d5-twtrsrc In-Reply-To: <1461787481-877-1-git-send-email-dturner@twopensource.com> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: =46rom: Nguy=E1=BB=85n Th=C3=A1i Ng=E1=BB=8Dc Duy Later, we will introduce git index-helper to share this memory with other git processes. We only unmap it when we discard the index (although the kernel may of course choose to page it out). Signed-off-by: Nguy=E1=BB=85n Th=C3=A1i Ng=E1=BB=8Dc Duy Signed-off-by: David Turner --- cache.h | 3 +++ read-cache.c | 13 ++++++++++++- 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/cache.h b/cache.h index b829410..4180e2b 100644 --- a/cache.h +++ b/cache.h @@ -333,11 +333,14 @@ struct index_state { struct split_index *split_index; struct cache_time timestamp; unsigned name_hash_initialized : 1, + keep_mmap : 1, initialized : 1; struct hashmap name_hash; struct hashmap dir_hash; unsigned char sha1[20]; struct untracked_cache *untracked; + void *mmap; + size_t mmap_size; }; =20 extern struct index_state the_index; diff --git a/read-cache.c b/read-cache.c index 16cc487..3cb0ec3 100644 --- a/read-cache.c +++ b/read-cache.c @@ -1574,6 +1574,10 @@ int do_read_index(struct index_state *istate, co= nst char *path, int must_exist) mmap =3D xmmap(NULL, mmap_size, PROT_READ, MAP_PRIVATE, fd, 0); if (mmap =3D=3D MAP_FAILED) die_errno("unable to map index file"); + if (istate->keep_mmap) { + istate->mmap =3D mmap; + istate->mmap_size =3D mmap_size; + } close(fd); =20 hdr =3D mmap; @@ -1626,11 +1630,13 @@ int do_read_index(struct index_state *istate, c= onst char *path, int must_exist) src_offset +=3D 8; src_offset +=3D extsize; } - munmap(mmap, mmap_size); + if (!istate->keep_mmap) + munmap(mmap, mmap_size); return istate->cache_nr; =20 unmap: munmap(mmap, mmap_size); + istate->mmap =3D NULL; die("index file corrupt"); } =20 @@ -1655,6 +1661,7 @@ int read_index_from(struct index_state *istate, c= onst char *path) discard_index(split_index->base); else split_index->base =3D xcalloc(1, sizeof(*split_index->base)); + split_index->base->keep_mmap =3D istate->keep_mmap; ret =3D do_read_index(split_index->base, git_path("sharedindex.%s", sha1_to_hex(split_index->base_sha1)), 1); @@ -1698,6 +1705,10 @@ int discard_index(struct index_state *istate) free(istate->cache); istate->cache =3D NULL; istate->cache_alloc =3D 0; + if (istate->keep_mmap && istate->mmap) { + munmap(istate->mmap, istate->mmap_size); + istate->mmap =3D NULL; + } discard_split_index(istate); free_untracked_cache(istate->untracked); istate->untracked =3D NULL; --=20 2.4.2.767.g62658d5-twtrsrc