Reimplement syscall wrappers for linux/arm64 in terms of supported
syscalls (or in case of Ustat make it return ENOSYS) and remove the
manually added SYS_* consts for the deprecated syscalls. Adapted from
golang.org/x/sys/unix where this is already done since CL 119655.
Change-Id: I94ab48a4645924df3822497d0575f1a1573d509f
Reviewed-on: https://go-review.googlesource.com/c/go/+/199140
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
On linux/riscv64, the renameat syscall no longer exists and has been
superseded by renameat2. Thus we'll have to use Renameat2 to implement
Renameat on linux/riscv64 for #27532. Prepare for this by moving the
Renameat definition to the GOARCH specific files.
Follow CL 157899 which did the same for golang.org/x/sys/unix
Change-Id: I9670213cc3987df48fee962ddee36915a7785560
Reviewed-on: https://go-review.googlesource.com/c/go/+/192077
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
The Linux kernel faccessat system call does not take a flags parameter.
The flag parameter to the C library faccessat function is implemented in C.
The syscall.Faccessat function takes a flags parameter. In older releases
we have passed the flags parameter to the kernel, which ignored it.
In CL 120015 we started returning an error if any flags were set.
That seems clearly better than ignoring them, but it turns out that some
code was using the flags. The code was previously subtly broken.
Now it is obviously broken. That is better, but we can do better still:
we can implement the flags as the C library does. That is what this CL does.
Change-Id: I259bd6f240c3951e939b81c3032dead3d9c567b4
Reviewed-on: https://go-review.googlesource.com/126415
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Change the Pipe() function to use the pipe() syscall (which has a unique
calling convention on linux/mips) instead of using pipe2(). This allows
it work on kernels <2.6.27 when pipe2() was introduced.
Change-Id: I65dfbd2a02b64e777a8eb13013d718e356521be6
GitHub-Last-Rev: c483a06168
GitHub-Pull-Request: golang/go#26608
Reviewed-on: https://go-review.googlesource.com/125915
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Vladimir Stefanovic <vladimir.stefanovic@mips.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The getdents64 syscall is only available for mips64/mips64le starting
with Linux kernel 3.10. Since mips64le requires at least 4.8 according
to [1] (regarding #16848) using it should be fine.
[1] https://golang.org/wiki/MinimumRequirements
This CL changes the binary layout of type Dirent for mips64/mips64le,
but not the public API. But since the currently used layout doesn't
match the struct linux_dirent returned by the getdents syscall this
should be fine as well.
Fixes#23624
Change-Id: Iaa7306fa6e4442ad2fed41c60b37627a7314f117
Reviewed-on: https://go-review.googlesource.com/91055
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
This greatly improves the latency of starting a child process when
the Go process is using a lot of memory. Even though the kernel uses
copy-on-write, preparation for that can take up to several 100ms under
certain conditions. All other goroutines are suspended while starting
a subprocess so this latency directly affects total throughput.
With CLONE_VM the child process shares the same memory with the parent
process. On its own this would lead to conflicting use of the same
memory, so CLONE_VFORK is used to suspend the parent process until the
child releases the memory when switching to to the new program binary
via the exec syscall. When the parent process continues to run, one
has to consider the changes to memory that the child process did,
namely the return address of the syscall function needs to be restored
from a register.
A simple benchmark has shown a difference in latency of 16ms vs. 0.5ms
at 10GB memory usage. However, much higher latencies of several 100ms
have been observed in real world scenarios. For more information see
comments on #5838.
Fixes#5838
Change-Id: I6377d7bd8dcd00c85ca0c52b6683e70ce2174ba6
Reviewed-on: https://go-review.googlesource.com/37439
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Delete use stub from asm.s, leaving only a dummy file.
Deleting the file causes Windows build to fail.
Fixes#16607
Change-Id: Ic5a55e042e588f1e1bc6605a3d309d1eabdeb288
Reviewed-on: https://go-review.googlesource.com/36716
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
