| liburing |
| -------- |
| |
| This is the io_uring library, liburing. liburing provides helpers to setup and |
| teardown io_uring instances, and also a simplified interface for |
| applications that don't need (or want) to deal with the full kernel |
| side implementation. |
| |
| For more info on io_uring, please see: |
| |
| https://kernel.dk/io_uring.pdf |
| |
| Subscribe to [email protected] for io_uring related discussions |
| and development for both kernel and userspace. The list is archived here: |
| |
| https://lore.kernel.org/io-uring/ |
| |
| |
| kernel version dependency |
| -------------------------- |
| |
| liburing itself is not tied to any specific kernel release, and hence it's |
| possible to use the newest liburing release even on older kernels (and vice |
| versa). Newer features may only be available on more recent kernels, |
| obviously. |
| |
| |
| ulimit settings |
| --------------- |
| |
| io_uring accounts memory it needs under the rlimit memlocked option, which |
| can be quite low on some setups (64K). The default is usually enough for |
| most use cases, but bigger rings or things like registered buffers deplete |
| it quickly. root isn't under this restriction, but regular users are. Going |
| into detail on how to bump the limit on various systems is beyond the scope |
| of this little blurb, but check /etc/security/limits.conf for user specific |
| settings, or /etc/systemd/user.conf and /etc/systemd/system.conf for systemd |
| setups. This affects 5.11 and earlier, new kernels are less dependent |
| on RLIMIT_MEMLOCK as it is only used for registering buffers. |
| |
| |
| Regressions tests |
| ----------------- |
| |
| The bulk of liburing is actually regression/unit tests for both liburing and |
| the kernel io_uring support. Please note that this suite isn't expected to |
| pass on older kernels, and may even crash or hang older kernels! |
| |
| |
| License |
| ------- |
| |
| All software contained within this repo is dual licensed LGPL and MIT, see |
| COPYING and LICENSE, except for a header coming from the kernel which is |
| dual licensed GPL with a Linux-syscall-note exception and MIT, see |
| COPYING.GPL and <https://spdx.org/licenses/Linux-syscall-note.html>. |
| |
| Jens Axboe 2022-05-19 |
