Re: [PATCH] stdlib: reorganize stdlib Makefile routines by functionality

[abush wang <abushwangs@gmail.com>]

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Hi H.J.
Is there an updated version to solve this problem?

On Tue, Apr 2, 2024 at 11:54 AM abush wang <abushwangs@gmail.com> wrote:

> Hi, Lu
> it seems like there is some build issue:
> ```
> /usr/bin/ld: /tmp/cc1NV6qZ.ltrans2.ltrans.o: warning: relocation against
> `seen_eof_include_file' in read-only section `.text'
> /usr/bin/ld: /tmp/cc1NV6qZ.ltrans1.ltrans.o: in function `lang_add_wild':
> /builddir/build/BUILD/binutils-2.42.50/build-x86_64-redhat-linux/ld/../../ld/ldlang.c:8518:(.text+0xa108):
> undefined reference to `in_text_section_ordering_file'
> /usr/bin/ld:
> /builddir/build/BUILD/binutils-2.42.50/build-x86_64-redhat-linux/ld/../../ld/ldlang.c:8552:(.text+0xa3aa):
> undefined reference to `seen_eof_include_file'
> /usr/bin/ld:
> /builddir/build/BUILD/binutils-2.42.50/build-x86_64-redhat-linux/ld/../../ld/ldlang.c:8553:(.text+0xa3b8):
> undefined reference to `in_text_section_ordering_file'
> /usr/bin/ld:
> /builddir/build/BUILD/binutils-2.42.50/build-x86_64-redhat-linux/ld/../../ld/ldlang.c:8551:(.text+0xa48f):
> undefined reference to `in_text_section_ordering_file'
> /usr/bin/ld: /tmp/cc1NV6qZ.ltrans2.ltrans.o: in function
> `ldfile_open_command_file_1.lto_priv.0':
> /builddir/build/BUILD/binutils-2.42.50/build-x86_64-redhat-linux/ld/../../ld/ldfile.c:939:(.text+0x9fc2):
> undefined reference to `in_text_section_ordering_file'
> /usr/bin/ld:
> /builddir/build/BUILD/binutils-2.42.50/build-x86_64-redhat-linux/ld/../../ld/ldfile.c:965:(.text+0x9ff3):
> undefined reference to `in_text_section_ordering_file'
> /usr/bin/ld:
> /builddir/build/BUILD/binutils-2.42.50/build-x86_64-redhat-linux/ld/../../ld/ldfile.c:998:(.text+0xa0e7):
> undefined reference to `in_text_section_ordering_file'
> /usr/bin/ld:
> /builddir/build/BUILD/binutils-2.42.50/build-x86_64-redhat-linux/ld/../../ld/ldfile.c:995:(.text+0xa0f7):
> undefined reference to `seen_eof_include_file'
> /usr/bin/ld: warning: creating DT_TEXTREL in a PIE
> collect2: error: ld returned 1 exit status
> make[4]: *** [Makefile:1265: ld-new] Error 1
> make[3]: *** [Makefile:1903: all-recursive] Error 1
> make[2]: *** [Makefile:1092: all] Error 2
> make[1]: *** [Makefile:8046: all-ld] Error 2
> ```
>
> test by binutils-2.42.50-6.fc41.src.rpm
> this is my repo
> https://mirrors.aliyun.com/fedora/development/rawhide/Everything/x86_64/os/
> I have verified that the error reported is caused by these patches.
>
>
> On Mon, Apr 1, 2024 at 9:17 PM H.J. Lu <hjl.tools@gmail.com> wrote:
>
>> On Mon, Apr 1, 2024 at 6:13 AM Florian Weimer <fweimer@redhat.com> wrote:
>> >
>> > * abush wang:
>> >
>> > > This is test:
>> > > ```
>> > > uint64_t getnsecs() {
>> > >     uint32_t lo, hi;
>> > >     __asm__ __volatile__ (
>> > >         "rdtsc" : "=a"(lo), "=d"(hi)
>> > >     );
>> > >     return ((uint64_t)hi << 32) | lo;
>> > > }
>> > >
>> > > int main() {
>> > >     const int num_iterations = 1;
>> > >     uint64_t start, end, total_time = 0;
>> > >
>> > >     start = getnsecs();
>> > >     for (int i = 0; i < num_iterations; i++) {
>> > >         (void) lrand48();
>> > >     }
>> > >     end = getnsecs();
>> > >     total_time += (end - start);
>> > >
>> > >     printf("Average time for lrand48: %lu cycles\n", total_time /
>> num_iterations);
>> > >     return 0;
>> > > }
>> > > ```
>> > > before:
>> > > Average time for lrand48: 21418 cycles
>> > >
>> > > after:
>> > > Average time for lrand48: 9892 cycles
>> >
>> > Do you see this on x86-64?  So this isn't a displacement range issue?
>> >
>> > It could be that this is a random performance change due to code
>> > alignment, and not actually caused by the direct call distance.
>> >
>>
>> I have a linker patch to control section layout:
>>
>> https://patchwork.sourceware.org/project/binutils/list/?series=29973
>>
>> It can
>>
>> 1. Reduce gaps between text sections.
>> 2. Put hot text sections close to each other.
>>
>> If it can solve this issue, we should add this feature to ld.
>>
>> --
>> H.J.
>>
>

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