mirror of https://github.com/acidanthera/audk.git
bd907fb638
The current implementation calls both pack() and Buffer.write() Size
times. The new implementation calls both of these methods only once; the
full data to write are constructed locally [1]. The range() function is
replaced by xrange() because the latter is supposed to be faster / lighter
weight [2].
On my laptop, I tested the change as follows: I pre-built the series at
[3] with
build -a X64 -p OvmfPkg/OvmfPkgX64.dsc -t GCC48 -b DEBUG \
-D HTTP_BOOT_ENABLE -D SECURE_BOOT_ENABLE
(The series at [3] is relevant because it increases the size of one of the
padded regions by 8.5 MB, slowing down the build quite a bit.)
With all source code already compiled, repeating the above command takes
approximately 45 seconds. With the patch applied, it goes down to 29
seconds.
[1] http://stackoverflow.com/questions/27384093/fastest-way-to-write-huge-data-in-file
[2] https://docs.python.org/2/library/functions.html?highlight=xrange#xrange
[3] http://thread.gmane.org/gmane.comp.bios.edk2.devel/14214
We can also measure the impact with a synthetic test:
> import timeit
>
> test_old = """
> import struct, string, StringIO
> Size = (8 * 1024 + 512) * 1024
> Buffer = StringIO.StringIO()
> PadData = 0xFF
> for i in range(0, Size):
> Buffer.write(struct.pack('B', PadData))
> """
>
> test_new = """
> import struct, string, StringIO
> Size = (8 * 1024 + 512) * 1024
> Buffer = StringIO.StringIO()
> PadByte = struct.pack('B', 0xFF)
> PadData = string.join(PadByte for i in xrange(0, Size))
> Buffer.write(PadData)
> """
>
> print(timeit.repeat(stmt=test_old, number=1, repeat=3))
> print(timeit.repeat(stmt=test_new, number=1, repeat=3))
The output is
[8.231637001037598, 8.81188416481018, 8.948754072189331]
[0.5503702163696289, 0.5461571216583252, 0.578315019607544]
Cc: Yonghong Zhu <yonghong.zhu@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
|
||
|---|---|---|
| AppPkg | ||
| ArmPkg | ||
| ArmPlatformPkg | ||
| ArmVirtPkg | ||
| BaseTools | ||
| BeagleBoardPkg | ||
| Conf | ||
| CorebootModulePkg | ||
| CorebootPayloadPkg | ||
| CryptoPkg | ||
| DuetPkg | ||
| EdkCompatibilityPkg | ||
| EdkShellBinPkg | ||
| EdkShellPkg | ||
| EmbeddedPkg | ||
| EmulatorPkg | ||
| FatBinPkg | ||
| FatPkg | ||
| IntelFrameworkModulePkg | ||
| IntelFrameworkPkg | ||
| IntelFsp2Pkg | ||
| IntelFsp2WrapperPkg | ||
| IntelFspPkg | ||
| IntelFspWrapperPkg | ||
| IntelSiliconPkg | ||
| MdeModulePkg | ||
| MdePkg | ||
| NetworkPkg | ||
| Nt32Pkg | ||
| Omap35xxPkg | ||
| OptionRomPkg | ||
| OvmfPkg | ||
| PcAtChipsetPkg | ||
| PerformancePkg | ||
| QuarkPlatformPkg | ||
| QuarkSocPkg | ||
| SecurityPkg | ||
| ShellBinPkg | ||
| ShellPkg | ||
| SourceLevelDebugPkg | ||
| StdLib | ||
| StdLibPrivateInternalFiles | ||
| UefiCpuPkg | ||
| UnixPkg | ||
| Vlv2DeviceRefCodePkg | ||
| Vlv2TbltDevicePkg | ||
| .gitignore | ||
| BuildNotes2.txt | ||
| Edk2Setup.bat | ||
| Maintainers.txt | ||
| edksetup.bat | ||
| edksetup.sh | ||