Re: Bug#1093243: Upgrade to 6.1.123 kernel causes mariadb hangs

[Xan Charbonnet <xan@charbonnet.com>]

On 1/23/25 20:49, Salvatore Bonaccorso wrote:
> Additionally please try with 6.1.120 and revert this commit
>
> 3ab9326f93ec ("io_uring: wake up optimisations")
>
> (which landed in 6.1.120).
>
> If that solves the problem maybe we miss some prequisites in the 6.1.y
> series here?


I hope I did all this right.  I found this:
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=3181e22fb79910c7071e84a43af93ac89e8a7106

and attempted to undo that change in the vanilla 6.1.124 source by 
making the following change to io_uring/io_uring.c:

585,594d584
< static inline void __io_cq_unlock_post_flush(struct io_ring_ctx *ctx)
<       __releases(ctx->completion_lock)
< {
<       io_commit_cqring(ctx);
<       spin_unlock(&ctx->completion_lock);
<       io_commit_cqring_flush(ctx);
<       if (!(ctx->flags & IORING_SETUP_DEFER_TASKRUN))
<               __io_cqring_wake(ctx);
< }
<
1352c1342
<       __io_cq_unlock_post_flush(ctx);
---
 >         __io_cq_unlock_post(ctx);


I rebooted into the resulting kernel and am happy to report that the 
problem did NOT occur!