148639 2015-08-31 11:08:18 -0700 [CMake] Build with Debug Fission on by default on Debug builds 2015-09-15 06:49:48 -0700 1 1 1 Unclassified WebKit WebKitGTK WebKit Nightly Build Unspecified Unspecified RESOLVED FIXED P2 Normal --- 131177 149161 1 clopez clopez achristensen cgarcia gyuyoung.kim mcatanzaro mrobinson ossy zan oldest_to_newest 1122220 0 clopez 2015-08-31 11:08:18 -0700 We are having some issues on the GTK Debug buildbots. The bots are running out of RAM sometimes. On bug 131177 support for building with Debug Fission was added. Now I suggest to enable this by default when building the Debug build. I have measured the memory usage of building with and without this option for the Debug build: * Without Debug fission: Max memory usage by the linker = 10.2 GB * With Debug fission: Max memory usage by the linker = 7.8 GB Not it only reduces the amount of RAM required to build WebKit in 2.4GB, but it also builds faster. Concerns about Debug Fission builds breaking ccache were sorted out with ccache 3.2.3 https://ccache.samba.org/releasenotes.html#_ccache_3_2_3 1122224 1 clopez 2015-08-31 11:24:15 -0700 Some more stats: * Rebuilding the Debug build from ccache without Debug fission: - Time to build = 06m:42s - Size of WebKitBuild/Debug = 16GB * Rebuilding the Debug build from ccache with Debug fission: - Time to build = 04m:05s - Size of WebKitBuild/Debug = 8.9G The time to build is mostly linking time, since I'm rebuilding from previously generated ccache DB. And this is on a system with an SSD. On a system with a rotational media it will probably improve build times further. Its also nice that the size of the build output has been reduced (almost to half). This will help to save disk space also. 1122235 2 260302 clopez 2015-08-31 11:46:16 -0700 Created attachment 260302 Patch 1122238 3 mrobinson 2015-08-31 11:50:54 -0700 Can you comment on compiler requirements? Does our minimum supported compiler also support debug fission? 1122245 4 clopez 2015-08-31 12:07:47 -0700 (In reply to comment #3) > Can you comment on compiler requirements? Does our minimum supported > compiler also support debug fission? According to https://gcc.gnu.org/wiki/DebugFission it is implemented on GCC 4.7 We already require GCC 4.9, so this shouldn't be a problem. I also tested this with Clang (version 3.6) and it worked without problems. 1122246 5 mcatanzaro 2015-08-31 12:09:55 -0700 (In reply to comment #3) > Can you comment on compiler requirements? Does our minimum supported > compiler also support debug fission? Clang has supported debug fission for a while now. GCC has supported it since 4.7 [1] and nowadays we require 4.8 or 4.9, depending on who you ask :), so we're good. It makes debug builds dramatically faster, especially incremental builds, so I agree it should be on by default. [1] http://gcc.gnu.org/wiki/DebugFission 1122271 6 260302 clopez 2015-08-31 13:28:37 -0700 Comment on attachment 260302 Patch Clearing flags on attachment: 260302 Committed r189179: <http://trac.webkit.org/changeset/189179> 1122272 7 clopez 2015-08-31 13:28:44 -0700 All reviewed patches have been landed. Closing bug. 260302 2015-08-31 11:46:16 -0700 2015-08-31 13:28:37 -0700 Patch bug-148639-20150831204559.patch text/plain 1563 clopez U3VidmVyc2lvbiBSZXZpc2lvbjogMTg5MTc4CmRpZmYgLS1naXQgYS9Tb3VyY2UvY21ha2UvT3B0 aW9uc0NvbW1vbi5jbWFrZSBiL1NvdXJjZS9jbWFrZS9PcHRpb25zQ29tbW9uLmNtYWtlCmluZGV4 IGI1ZjMyOWY1MmQ1MzYwMWE5ZjYzYTYwZTEzMDY4ZDIxNzk4ZGJmZjkuLjY2YWUzMDBlNTUyNTg5 NTMzZDFkODlhMDM0OTEwNTQ4ODQ1Y2JjNTIgMTAwNjQ0Ci0tLSBhL1NvdXJjZS9jbWFrZS9PcHRp b25zQ29tbW9uLmNtYWtlCisrKyBiL1NvdXJjZS9jbWFrZS9PcHRpb25zQ29tbW9uLmNtYWtlCkBA IC03OSwxMCArNzksMTcgQEAgaWYgKFVTRV9MRF9HT0xEKQogICAgICAgICBzZXQoQ01BS0VfU0hB UkVEX0xJTktFUl9GTEFHUyAiJHtDTUFLRV9FWEVfTElOS0VSX0ZMQUdTfSAtZnVzZS1sZD1nb2xk IC1XbCwtLWRpc2FibGUtbmV3LWR0YWdzIikKICAgICBlbHNlICgpCiAgICAgICAgIG1lc3NhZ2Uo V0FSTklORyAiR05VIGdvbGQgbGlua2VyIGlzbid0IGF2YWlsYWJsZSwgdXNpbmcgdGhlIGRlZmF1 bHQgc3lzdGVtIGxpbmtlci4iKQorICAgICAgICBzZXQoVVNFX0xEX0dPTEQgT0ZGKQogICAgIGVu ZGlmICgpCiBlbmRpZiAoKQogCi1vcHRpb24oREVCVUdfRklTU0lPTiAiVXNlIERlYnVnIEZpc3Np b24gc3VwcG9ydCIpCitzZXQoRU5BQkxFX0RFQlVHX0ZJU1NJT05fREVGQVVMVCBPRkYpCitpZiAo VVNFX0xEX0dPTEQgQU5EIENNQUtFX0JVSUxEX1RZUEUgU1RSRVFVQUwgIkRlYnVnIikKKyAgICBz ZXQoRU5BQkxFX0RFQlVHX0ZJU1NJT05fREVGQVVMVCBPTikKK2VuZGlmICgpCisKK29wdGlvbihE RUJVR19GSVNTSU9OICJVc2UgRGVidWcgRmlzc2lvbiBzdXBwb3J0IiAke0VOQUJMRV9ERUJVR19G SVNTSU9OX0RFRkFVTFR9KQorCiBpZiAoREVCVUdfRklTU0lPTikKICAgICBpZiAoTk9UIFVTRV9M RF9HT0xEKQogICAgICAgICBtZXNzYWdlKEZBVEFMX0VSUk9SICJOZWVkIEdOVSBnb2xkIGxpbmtl ciBmb3IgRGVidWcgRmlzc2lvbiBzdXBwb3J0IikKZGlmZiAtLWdpdCBhL0NoYW5nZUxvZyBiL0No YW5nZUxvZwppbmRleCA3Y2VkNWMyNDU3NmQ3OGNhNzc2NGVjYjRjOTEyYWEwMTVlNjVlOGU3Li5j NDFmMmZkOWI2MDdlOWJhNWJjOGQ3ZTg1OGVhNTU2ZjQ4ODE1OWQ5IDEwMDY0NAotLS0gYS9DaGFu Z2VMb2cKKysrIGIvQ2hhbmdlTG9nCkBAIC0xLDMgKzEsMTIgQEAKKzIwMTUtMDgtMzEgIENhcmxv cyBBbGJlcnRvIExvcGV6IFBlcmV6ICA8Y2xvcGV6QGlnYWxpYS5jb20+CisKKyAgICAgICAgW0NN YWtlXSBCdWlsZCB3aXRoIERlYnVnIEZpc3Npb24gb24gYnkgZGVmYXVsdCBvbiBEZWJ1ZyBidWls ZHMuCisgICAgICAgIGh0dHBzOi8vYnVncy53ZWJraXQub3JnL3Nob3dfYnVnLmNnaT9pZD0xNDg2 MzkKKworICAgICAgICBSZXZpZXdlZCBieSBOT0JPRFkgKE9PUFMhKS4KKworICAgICAgICAqIFNv dXJjZS9jbWFrZS9PcHRpb25zQ29tbW9uLmNtYWtlOgorCiAyMDE1LTA4LTI5ICBBbGV4IENocmlz dGVuc2VuICA8YWNocmlzdGVuc2VuQHdlYmtpdC5vcmc+CiAKICAgICAgICAgVW5yZXZpZXdlZCBi dWlsZCBmaXggYWZ0ZXIgcjE3OTkyMy4K