2022-11-04 09:03:38

by Tvrtko Ursulin

[permalink] [raw]
Subject: Re: [RFC][PATCH v3 13/33] timers: drm: Use timer_shutdown_sync() before freeing timer


Hi,

On 04/11/2022 05:41, Steven Rostedt wrote:
> From: "Steven Rostedt (Google)" <[email protected]>
>
> Before a timer is freed, timer_shutdown_sync() must be called.
>
> Link: https://lore.kernel.org/all/[email protected]/
>
> Cc: "Noralf Trønnes" <[email protected]>
> Cc: David Airlie <[email protected]>
> Cc: Daniel Vetter <[email protected]>
> Cc: Jani Nikula <[email protected]>
> Cc: Joonas Lahtinen <[email protected]>
> Cc: Rodrigo Vivi <[email protected]>
> Cc: Tvrtko Ursulin <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Signed-off-by: Steven Rostedt (Google) <[email protected]>
> ---
> drivers/gpu/drm/gud/gud_pipe.c | 2 +-
> drivers/gpu/drm/i915/i915_sw_fence.c | 2 +-

If it stays all DRM drivers in one patch then I guess it needs to go via
drm-misc, which for i915 would be okay I think in this case since patch
is extremely unlikely to clash with anything. Or split it up per driver
and then we can handle it in drm-intel-next once core functionality is in.

We do however have some more calls to del_timer_sync, where freeing is
perhaps not immediately next to the site in code, but things definitely
get freed like on module unload. Would we need to convert all of them to
avoid some, presumably new, warnings?

Regards,

Tvrtko

> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/gud/gud_pipe.c b/drivers/gpu/drm/gud/gud_pipe.c
> index 7c6dc2bcd14a..08429bdd57cf 100644
> --- a/drivers/gpu/drm/gud/gud_pipe.c
> +++ b/drivers/gpu/drm/gud/gud_pipe.c
> @@ -272,7 +272,7 @@ static int gud_usb_bulk(struct gud_device *gdrm, size_t len)
>
> usb_sg_wait(&ctx.sgr);
>
> - if (!del_timer_sync(&ctx.timer))
> + if (!timer_shutdown_sync(&ctx.timer))
> ret = -ETIMEDOUT;
> else if (ctx.sgr.status < 0)
> ret = ctx.sgr.status;
> diff --git a/drivers/gpu/drm/i915/i915_sw_fence.c b/drivers/gpu/drm/i915/i915_sw_fence.c
> index 6fc0d1b89690..bfaa9a67dc35 100644
> --- a/drivers/gpu/drm/i915/i915_sw_fence.c
> +++ b/drivers/gpu/drm/i915/i915_sw_fence.c
> @@ -465,7 +465,7 @@ static void irq_i915_sw_fence_work(struct irq_work *wrk)
> struct i915_sw_dma_fence_cb_timer *cb =
> container_of(wrk, typeof(*cb), work);
>
> - del_timer_sync(&cb->timer);
> + timer_shutdown_sync(&cb->timer);
> dma_fence_put(cb->dma);
>
> kfree_rcu(cb, rcu);


2022-11-04 19:39:25

by Steven Rostedt

[permalink] [raw]
Subject: Re: [RFC][PATCH v3 13/33] timers: drm: Use timer_shutdown_sync() before freeing timer

On Fri, 4 Nov 2022 08:48:28 +0000
Tvrtko Ursulin <[email protected]> wrote:

> If it stays all DRM drivers in one patch then I guess it needs to go via
> drm-misc, which for i915 would be okay I think in this case since patch
> is extremely unlikely to clash with anything. Or split it up per driver
> and then we can handle it in drm-intel-next once core functionality is in.
>
> We do however have some more calls to del_timer_sync, where freeing is
> perhaps not immediately next to the site in code, but things definitely
> get freed like on module unload. Would we need to convert all of them to
> avoid some, presumably new, warnings?


I'm happy to split this patch up. I just got a bit lazy and started
just grouping via entire subsystems. You should see the networking
patch ;-)

-- Steve