From owner-svn-src-all@FreeBSD.ORG Mon Mar 16 14:24:49 2015 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 105A8FB5; Mon, 16 Mar 2015 14:24:49 +0000 (UTC) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id EF7F1899; Mon, 16 Mar 2015 14:24:48 +0000 (UTC) Received: from svn.freebsd.org ([127.0.1.70]) by svn.freebsd.org (8.14.9/8.14.9) with ESMTP id t2GEOmQT041814; Mon, 16 Mar 2015 14:24:48 GMT (envelope-from glebius@FreeBSD.org) Received: (from glebius@localhost) by svn.freebsd.org (8.14.9/8.14.9/Submit) id t2GEOm0D041812; Mon, 16 Mar 2015 14:24:48 GMT (envelope-from glebius@FreeBSD.org) Message-Id: <201503161424.t2GEOm0D041812@svn.freebsd.org> X-Authentication-Warning: svn.freebsd.org: glebius set sender to glebius@FreeBSD.org using -f From: Gleb Smirnoff Date: Mon, 16 Mar 2015 14:24:48 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r280136 - head/sys/vm X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.18-1 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: Mon, 16 Mar 2015 14:24:49 -0000 Author: glebius Date: Mon Mar 16 14:24:47 2015 New Revision: 280136 URL: https://svnweb.freebsd.org/changeset/base/280136 Log: Provide a comment explaining r279688. Suggested by: alc Modified: head/sys/vm/vnode_pager.c Modified: head/sys/vm/vnode_pager.c ============================================================================== --- head/sys/vm/vnode_pager.c Mon Mar 16 14:12:41 2015 (r280135) +++ head/sys/vm/vnode_pager.c Mon Mar 16 14:24:47 2015 (r280136) @@ -772,6 +772,14 @@ vnode_pager_generic_getpages(struct vnod bsize = vp->v_mount->mnt_stat.f_iosize; foff = IDX_TO_OFF(m[reqpage]->pindex); + /* + * Synchronous and asynchronous paging operations use different + * free pbuf counters. This is done to avoid asynchronous requests + * to consume all pbufs. + * Allocate the pbuf at the very beginning of the function, so that + * if we are low on certain kind of pbufs don't even proceed to BMAP, + * but sleep. + */ freecnt = iodone != NULL ? &vnode_async_pbuf_freecnt : &vnode_pbuf_freecnt; bp = getpbuf(freecnt);