Closed Bug 428532 Opened 15 years ago Closed 7 years ago
single compiler invocation for C++ files per dir
shaver had a crazy scheme, and I have a patch, which I'll attach when my build finishes. This works on Win32/VC++, might need some tweaking for GCC.
Without: real 27m37.750s With: real 21m51.250s Built without -janything, just a straight |make| on a Core 2 Duo/2gb ram WinXP system.
Assignee: nobody → ted.mielczarek
Status: NEW → ASSIGNED
With -j4, without the patch: real 20m52.047s With -j4, with the patch: real 21m18.469s Makes sense, since we're effectively serializing the C++ compilation phase.
Yeah, without being able to ||ize dirs, we'll hit a wall there, though I suspect that we use less CPU with the patch even in the -j4 case, so it might still be a win on more-constrained boxes like the VM-hosted tboxes. Nonetheless, I am sad.
FWIW, I tweaked the patch to work with gcc on Linux. With -j4, without the patch: real 18m With -j4, with the patch: real 30m The PROG_SEPARATE_OBJS change was necessary for xremote: http://bonsai.mozilla.org/cvsblame.cgi?file=/mozilla/widget/src/xremoteclient/Makefile.in&rev=1.23&root=/cvsroot&mark=74-76#71
(In reply to comment #4) > With -j4, without the patch: > real 18m > > With -j4, with the patch: > real 30m :(
This would probably be better with bug 167254.
This is the magic+tweaks patch updated to trunk.
Note to self: I should add something like mddepend.pl does to the deps for $OBJENTRY), so that if any of the object files are missing, it gets rebuilt.
So the data in bug 461395 suggests that this is nice on Windows (with the two patches combined), but break-even or a loss on other platforms. I'm going to tweak this patch so that we'll only enable it on Windows. In fact, the exact logic if going to be something like: if building on Windows: if (makefile requests single-pass-compile) or (building with -j1): enable single-pass-compile Since on Windows it looks to be always a win in the -j1 case, we should enable it there. Otherwise, directories will have to opt-in, since they'll only see a win if they get PARALLEL_DIRS. I'll make content/ use this since it's clearly a win there.
without this patch, building Fennec for WinMo: real 85m42.050s user 3m9.826s sys 8m33.697s with this patch, building Fennec for WinMo: real 61m52.327s user 2m46.921s sys 7m26.657s ummm....can we land this now? Ted, one note I deleted the line with "OBJENTRY = OBJENTRY.BOGUS" because it was breaking the build.
Attachment #344642 - Attachment is obsolete: true
This is simply a better patch. ted made some improvements and I tacked on the use of MSVC9+'s /MP compiler flag. (http://msdn.microsoft.com/en-us/library/bb385193.aspx) Needs the patch from bug 538606 applied as well.
I had to revert the _VPATH_SRCS changes to fix bustage. It seems to work fine regardless, but I can't vouch for its correctness.
Fix a WinCE bug, I missed patching a link command line in the $(PROGRAM) link rule.
This is still breaking the WinMo builds on try server (but not the WinCE builds). blassey thinks his patch in bug 533542 might fix it. I've pushed a build with that patch + this patch to the try server to test.
This passed the try server when combined with bug 533542.
If you have some way of knowing that you're -j1 then there seems to be an easier way of implementing this by adding a rule along these lines: $(TARGETS):: $(CPPSRCS) $(ELOG) $(CCC) -c $(COMPILE_CXXFLAGS) $? early on in the Makefile. (Without -j1 this won't compile the files quickly enough to stop the %.$(OBJ_SUFFIX) rules taking effect.) Either way though, I'm not sure how you expect dependency information to stay up-to-date.
I tried filtering MAKEFLAGS for -j1, but it apparently just doesn't work. I'm not sure what you mean about the dependency information, $(OBJENTRY) depends on $(CPPSRCS).
(In reply to comment #19) > I tried filtering MAKEFLAGS for -j1, but it apparently just doesn't work. If you use -j1 then MAKEFLAGS won't have any j option at all. (Submakes run with -j and --jobserver-fds.) > I'm not sure what you mean about the dependency information, $(OBJENTRY) > depends on $(CPPSRCS). So what about changes to headers?
cl's -MP option conflicts with -showIncludes, the subject of bug 518136, so I've dropped the former option.
I think we'll end up WONTFIXing this in favor of Bug 623617, but I'll leave this open for now.
Assignee: ted.mielczarek → nobody
I think we can reasonably WONTFIX this, considering bug 939583.
Status: ASSIGNED → RESOLVED
Closed: 7 years ago
Resolution: --- → WONTFIX
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