Re: [PATCH] BaseTools: Cannot store library cache of different arch together

["Steven Shi" <steven.shi@intel.com>]

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Hi Christian,

For the extra IO accesses for duplicated library, I plan to introduce the CopyFileOnChange() function to solve it. Below is the CopyFileOnChange() BZ, and I haven't sent its patch yet. The CopyFileOnChange() will ensure only once IO store/restore access for each library. To avoid duplicated library access is critical not only for the performance, but also for the writing data race in multi-threads.





Basetool need CopyFileOnChange function to avoid cache file writing race in multi-thread build

https://bugzilla.tianocore.org/show_bug.cgi?id=1894





Thanks



Steven Shi

Intel\SSG\FID\Firmware Infrastructure



> -----Original Message-----

> From: Rodriguez, Christian

> Sent: Tuesday, June 11, 2019 11:41 PM

> To: Shi, Steven <steven.shi@intel.com>; devel@edk2.groups.io

> Cc: Gao, Liming <liming.gao@intel.com>; Feng, Bob C <bob.c.feng@intel.com>

> Subject: RE: [PATCH] BaseTools: Cannot store library cache of different arch

> together

>

> The change looks good overall, but I'm concerned about the performance if

> there are multiple of the same library used by different modules. In this case

> the library will be copied once per arch per module. I'm not sure if it would

> make a giant impact, but just something to think about because you would be

> doing extra IO accesses for each duplicate library autogen.

>

> Possible suggestion:

> Is it possible to change the hash to include the arch? Or you can store a

> unique tuple pair like (lib.arch, lib) in the set to reduce the libraries being

> copied to a unique subset.

>

> Thanks,

> Christian

>

> >-----Original Message-----

> >From: Shi, Steven

> >Sent: Monday, June 10, 2019 10:53 PM

> >To: devel@edk2.groups.io<mailto:devel@edk2.groups.io>

> >Cc: Gao, Liming <liming.gao@intel.com<mailto:liming.gao@intel.com>>; Feng, Bob C

> ><bob.c.feng@intel.com<mailto:bob.c.feng@intel.com>>; Rodriguez, Christian

> ><christian.rodriguez@intel.com<mailto:christian.rodriguez@intel.com>>

> >Subject: [PATCH] BaseTools: Cannot store library cache of different arch

> >together

> >

> >https://bugzilla.tianocore.org/show_bug.cgi?id=1895

> >

> >Build cache cannot store cache for the same library modules in different arch

> >together. E.g. Both the below IA32 and X64 arch BaseLib caches should exist

> >after build Ovmf3264, but now only the one in X64 arch exist.

> >The reason is the current Basetool use a set() to same all library AutoGen

> >objects, but the different arch lib AutoGen objects have same __hash_ value

> >which comes from the lib MetaFile(The path of module file):

> >    def __hash__(self):

> >        return hash(self.MetaFile)

> >

> >So the different arch lib AutoGen objects are duplicated one to the set() and

> >only one can exist. This is why the Basetool can only store one arch cache for

> >library.

> >This patch avoid to use the set() as the container to save the library and

> >module objects because the objects might have same __hash__ value.

> >

> >Cc: Liming Gao <liming.gao@intel.com<mailto:liming.gao@intel.com>>

> >Cc: Bob Feng <bob.c.feng@intel.com<mailto:bob.c.feng@intel.com>>

> >Cc: Christian Rodriguez <christian.rodriguez@intel.com<mailto:christian.rodriguez@intel.com>>

> >Signed-off-by: Steven Shi <steven.shi@intel.com<mailto:steven.shi@intel.com>>

> >---

> > BaseTools/Source/Python/build/build.py | 13 +++----------

> > 1 file changed, 3 insertions(+), 10 deletions(-)

> >

> >diff --git a/BaseTools/Source/Python/build/build.py

> >b/BaseTools/Source/Python/build/build.py

> >index 0855d4561c..f7a79cbbab 100644

> >--- a/BaseTools/Source/Python/build/build.py

> >+++ b/BaseTools/Source/Python/build/build.py

> >@@ -2203,21 +2203,14 @@ class Build():

> >             RemoveDirectory(os.path.dirname(GlobalData.gDatabasePath), True)

> >

> >     def CreateAsBuiltInf(self):

> >-        all_lib_set = set()

> >-        all_mod_set = set()

> >         for Module in self.BuildModules:

> >             Module.CreateAsBuiltInf()

> >-            all_mod_set.add(Module)

> >+            for lib in Module.LibraryAutoGenList:

> >+                lib.CreateAsBuiltInf(True)

> >         for Module in self.HashSkipModules:

> >             Module.CreateAsBuiltInf(True)

> >-            all_mod_set.add(Module)

> >-        for Module in all_mod_set:

> >             for lib in Module.LibraryAutoGenList:

> >-                all_lib_set.add(lib)

> >-        for lib in all_lib_set:

> >-            lib.CreateAsBuiltInf(True)

> >-        all_lib_set.clear()

> >-        all_mod_set.clear()

> >+                lib.CreateAsBuiltInf(True)

> >         self.BuildModules = []

> >         self.HashSkipModules = []

> >     ## Do some clean-up works when error occurred

> >--

> >2.17.1.windows.2



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