| Commit message (Collapse) | Author | Age | Files | Lines | |
|---|---|---|---|---|---|
| * | os, internal/poll, internal/syscall/unix: use copy_file_range on Linux | Andrei Tudor Călin | 2020-04-28 | 1 | -1/+1 |
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linux 4.5 introduced (and Linux 5.3 refined) the copy_file_range system call, which allows file systems the opportunity to implement copy acceleration techniques. This commit adds support for copy_file_range(2) to the os package. Introduce a new ReadFrom method on *os.File, which makes *os.File implement the io.ReaderFrom interface. If dst and src are both files, this enables io.Copy(dst, src) to call dst.ReadFrom(src), which, in turn, will call copy_file_range(2) if possible. If copy_file_range(2) is not supported by the host kernel, or if either of dst or src refers to a non-regular file, ReadFrom falls back to the regular io.Copy code path. Add internal/poll.CopyFileRange, which acquires locks on the appropriate poll.FDs and performs the actual work, as well as internal/syscall/unix.CopyFileRange, which wraps the copy_file_range system call itself at the lowest level. Rework file layout in internal/syscall/unix to accomodate the additional system call numbers needed for copy_file_range. Merge these definitions with the ones used by getrandom(2) into sysnum_linux_$GOARCH.go files. A note on additional optimizations: if dst and src both refer to pipes in the invocation dst.ReadFrom(src), we could, in theory, use the existing splice(2) code in package internal/poll to splice directly from src to dst. Attempting this runs into trouble with the poller, however. If we call splice(src, dst) and see EAGAIN, we cannot know if it came from src not being ready for reading or dst not being ready for writing. The write end of src and the read end of dst are not under our control, so we cannot reliably use the poller to wait for readiness. Therefore, it seems infeasible to use the new ReadFrom method to splice between pipes directly. In conclusion, for now, the only optimization enabled by the new ReadFrom method on *os.File is the copy_file_range optimization. Fixes #36817. Change-Id: I696372639fa0cdf704e3f65414f7321fc7d30adb Reviewed-on: https://go-review.googlesource.com/c/go/+/229101 Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org> | ||||
| * | internal/syscall/unix: omit unnecessary randomTrap check in GetRandom | Tobias Klauser | 2018-10-24 | 1 | -3/+0 |
| | | | | | | | | | | | | | The randomTrap const is initialized to a non-zero value for linux in getrandom_linux_$GOARCH.go and for freebsd in getrandom_freebsd.go directly since CL 16662. Thus, omit the unnecessary check. Change-Id: Id20cd628dfe6fab9908fa5258c3132e3b422a6b4 Reviewed-on: https://go-review.googlesource.com/c/144108 Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org> | ||||
| * | all: make copyright headers consistent with one space after period | Brad Fitzpatrick | 2016-03-01 | 1 | -1/+1 |
| | | | | | | | | | | | | | | | | | | | | | | | This is a subset of https://golang.org/cl/20022 with only the copyright header lines, so the next CL will be smaller and more reviewable. Go policy has been single space after periods in comments for some time. The copyright header template at: https://golang.org/doc/contribute.html#copyright also uses a single space. Make them all consistent. Change-Id: Icc26c6b8495c3820da6b171ca96a74701b4a01b0 Reviewed-on: https://go-review.googlesource.com/20111 Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> | ||||
| * | internal/syscall/unix: eliminate non-trivial randomTrap initializer | Matthew Dempsky | 2015-11-05 | 1 | -9/+0 |
| | | | | | | | | | | | | | | | While here, enable getrandom on arm64 too (using the value found in include/uapi/asm-generic/unistd.h, which seems to match up with other GOARCH=arm64 syscall numbers). Updates #10848. Change-Id: I5ab36ccf6ee8d5cc6f0e1a61d09f0da7410288b9 Reviewed-on: https://go-review.googlesource.com/16662 Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org> | ||||
| * | internal/syscall: move to unix subdirectory | Ian Lance Taylor | 2015-04-15 | 1 | -0/+58 |
| Move the single file from internal/syscall to internal/syscall/unix, to match the golang.org/x/sys layout. Change-Id: I2fb2832b4cb22efc7666bd276f5401ac3e73dc40 Reviewed-on: https://go-review.googlesource.com/8972 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Reviewed-by: Rob Pike <r@golang.org> | |||||
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