From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from arroyo.ext.ti.com (arroyo.ext.ti.com [192.94.94.40]) by mail.openembedded.org (Postfix) with ESMTP id 1006960D0B for ; Mon, 5 May 2014 00:34:39 +0000 (UTC) Received: from dlelxv90.itg.ti.com ([172.17.2.17]) by arroyo.ext.ti.com (8.13.7/8.13.7) with ESMTP id s450YdPG030184; Sun, 4 May 2014 19:34:39 -0500 Received: from DLEE71.ent.ti.com (dlee71.ent.ti.com [157.170.170.114]) by dlelxv90.itg.ti.com (8.14.3/8.13.8) with ESMTP id s450Ydjc013689; Sun, 4 May 2014 19:34:39 -0500 Received: from dlep33.itg.ti.com (157.170.170.75) by DLEE71.ent.ti.com (157.170.170.114) with Microsoft SMTP Server id 14.3.174.1; Sun, 4 May 2014 19:34:39 -0500 Received: from [172.22.143.171] (ileax41-snat.itg.ti.com [10.172.224.153]) by dlep33.itg.ti.com (8.14.3/8.13.8) with ESMTP id s450YdV7018244; Sun, 4 May 2014 19:34:39 -0500 Message-ID: <5366DC9E.1020702@ti.com> Date: Sun, 4 May 2014 19:34:38 -0500 From: Joel Fernandes User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.1.1 MIME-Version: 1.0 To: Tyler Hall References: <5366A8B5.6020900@ti.com> In-Reply-To: Cc: Patches and discussions about the oe-core layer Subject: Re: Quick question about OE-core/bitbake's re-building X-BeenThere: openembedded-core@lists.openembedded.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Patches and discussions about the oe-core layer List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 05 May 2014 00:34:41 -0000 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit On 05/04/2014 04:52 PM, Tyler Hall wrote: > On Sun, May 4, 2014 at 4:53 PM, Joel Fernandes > wrote: > > How does it figure out when it needs to rebuild a package? > > > Bitbake generates hashes for every task that are based on the data that > will be used when running the task. This includes the body of the task > function, any variables it references, checksums of required files, and > hashes of tasks it depends on. This data is stored for each task in > $BUILDDIR/tmp/stamps. The task will re-run if a matching sigdata file > does not exist in the stamps directory. You can run bitbake-dumpsig on a > sigdata file to see what metadata changes will cause the task to rebuild. > > For example if I modify the file: > ../meta/recipes-core/systemd/systemd-serialgetty/serial-getty@.service > > Does it track the modification time to know it needs to rebuild > "systemd-serialgetty"? > > Because doing such a modification didn't cause it to rebuild. > Thanks for your reply, that was helpful. > The modification time won't trigger a rebuild since the contents hash > the same. Changing the contents of the file should trigger a rebuild, > though. Makes sense. That's what I observed. However one thing, is the updates don't happen if you revert the changes back to what it used to be in an earlier revision. For example if I make changes such that task hash is now X Then I build, and its called r0.0. Then I make some more changes such that the hash is now Y And it becomes r0.1. Then after some more changes, it becomes X. Now instead of rebuilding and calling it r0.2, the rebuild doesn't happen. I wonder if this is the right thing, or the updates should continue to roll. -Joel