On Fri, Nov 22, 2024 at 03:55:23PM -0600, Sam Protsenko wrote: > It's an Exynos based board with eMMC, so it uses DW MMC driver, with > Exynos glue layer on top of it, so: > > drivers/mmc/host/dw_mmc.c > drivers/mmc/host/dw_mmc-exynos.c > > I'm using the regular ARM64 defconfig. Nothing fancy about this setup > neither, the device tree with eMMC definition (mmc_0) is here: > > arch/arm64/boot/dts/exynos/exynos850-e850-96.dts Thanks. eMMC itself never looks at the ioprio field. > FWIW, I was able to narrow down the issue to dd_insert_request() > function. With this hack the freeze is gone: Sounds like it isn't the driver that matters here, but the scheduler. > > 8<-------------------------------------------------------------------->8 > diff --git a/block/mq-deadline.c b/block/mq-deadline.c > index acdc28756d9d..83d272b66e71 100644 > --- a/block/mq-deadline.c > +++ b/block/mq-deadline.c > @@ -676,7 +676,7 @@ static void dd_insert_request(struct blk_mq_hw_ctx > *hctx, struct request *rq, > struct request_queue *q = hctx->queue; > struct deadline_data *dd = q->elevator->elevator_data; > const enum dd_data_dir data_dir = rq_data_dir(rq); > - u16 ioprio = req_get_ioprio(rq); > + u16 ioprio = 0; /* the same as old req->ioprio */ > u8 ioprio_class = IOPRIO_PRIO_CLASS(ioprio); > struct dd_per_prio *per_prio; > enum dd_prio prio; > 8<-------------------------------------------------------------------->8 > > Does it tell you anything about where the possible issue can be? Can you dump the ioprities you see here with and without the reverted patch?