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From: Matthew Brost <matthew.brost@intel.com>
To: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: intel-xe@lists.freedesktop.org, dri-devel@lists.freedesktop.org
Subject: Re: [Intel-xe] [PATCH 05/14] drm/xe: Convert GuC CT print to snapshot capture and print.
Date: Tue, 2 May 2023 05:27:08 +0000	[thread overview]
Message-ID: <ZFCfLB9bPSLACRsO@DUT025-TGLU.fm.intel.com> (raw)
In-Reply-To: <20230426205713.512695-6-rodrigo.vivi@intel.com>

On Wed, Apr 26, 2023 at 04:57:04PM -0400, Rodrigo Vivi wrote:
> The goal is to allow for a snapshot capture to be taken at the time
> of the crash, while the print out can happen at a later time through
> the exposed devcoredump virtual device.
> 
> Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_guc_ct.c       | 132 +++++++++++++++++++++++----
>  drivers/gpu/drm/xe/xe_guc_ct.h       |   7 +-
>  drivers/gpu/drm/xe/xe_guc_ct_types.h |  26 ++++++
>  3 files changed, 145 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_guc_ct.c b/drivers/gpu/drm/xe/xe_guc_ct.c
> index e16e5fe37ed4..0b7b95dbd9be 100644
> --- a/drivers/gpu/drm/xe/xe_guc_ct.c
> +++ b/drivers/gpu/drm/xe/xe_guc_ct.c
> @@ -1095,31 +1095,26 @@ static void g2h_worker_func(struct work_struct *w)
>  	xe_device_mem_access_put(ct_to_xe(ct));
>  }
>  
> -static void guc_ct_ctb_print(struct xe_device *xe, struct guc_ctb *ctb,
> -			     struct drm_printer *p)
> +static void guc_ctb_snapshot_capture(struct xe_device *xe, struct guc_ctb *ctb,
> +				     struct guc_ctb_snapshot *snapshot)
>  {
>  	u32 head, tail;
>  
> -	drm_printf(p, "\tsize: %d\n", ctb->info.size);
> -	drm_printf(p, "\tresv_space: %d\n", ctb->info.resv_space);
> -	drm_printf(p, "\thead: %d\n", ctb->info.head);
> -	drm_printf(p, "\ttail: %d\n", ctb->info.tail);
> -	drm_printf(p, "\tspace: %d\n", ctb->info.space);
> -	drm_printf(p, "\tbroken: %d\n", ctb->info.broken);
> +	snapshot->cmds = kmalloc_array(ctb->info.size, sizeof(u32), GFP_ATOMIC);

So since this GFP_ATOMIC I assume this so we can call this code from the
TDR or a CTB handler (dma fence signaling paths)? Also I don't see
where you check for this allocation failing.

>  
> -	head = desc_read(xe, ctb, head);
> -	tail = desc_read(xe, ctb, tail);
> -	drm_printf(p, "\thead (memory): %d\n", head);
> -	drm_printf(p, "\ttail (memory): %d\n", tail);
> -	drm_printf(p, "\tstatus (memory): 0x%x\n", desc_read(xe, ctb, status));
> +	xe_map_memcpy_from(xe, &snapshot->desc, &ctb->desc, 0,
> +			   sizeof(struct guc_ct_buffer_desc));
> +	memcpy(&snapshot->info, &ctb->info, sizeof(struct guc_ctb_info));
> +
> +	head = snapshot->desc.head;
> +	tail = snapshot->desc.tail;
>  
>  	if (head != tail) {
>  		struct iosys_map map =
>  			IOSYS_MAP_INIT_OFFSET(&ctb->cmds, head * sizeof(u32));
>  
>  		while (head != tail) {
> -			drm_printf(p, "\tcmd[%d]: 0x%08x\n", head,
> -				   xe_map_rd(xe, &map, 0, u32));
> +			snapshot->cmds[head] = xe_map_rd(xe, &map, 0, u32);
>  			++head;
>  			if (head == ctb->info.size) {
>  				head = 0;
> @@ -1131,20 +1126,119 @@ static void guc_ct_ctb_print(struct xe_device *xe, struct guc_ctb *ctb,
>  	}
>  }
>  
> -void xe_guc_ct_print(struct xe_guc_ct *ct, struct drm_printer *p)
> +static void guc_ctb_snapshot_print(struct guc_ctb_snapshot *snapshot,
> +				   struct drm_printer *p)
> +{
> +	u32 head, tail;
> +
> +	drm_printf(p, "\tsize: %d\n", snapshot->info.size);
> +	drm_printf(p, "\tresv_space: %d\n", snapshot->info.space);
> +	drm_printf(p, "\thead: %d\n", snapshot->info.head);
> +	drm_printf(p, "\ttail: %d\n", snapshot->info.tail);
> +	drm_printf(p, "\tspace: %d\n", snapshot->info.space);
> +	drm_printf(p, "\tbroken: %d\n", snapshot->info.broken);
> +	drm_printf(p, "\thead (memory): %d\n", snapshot->desc.head);
> +	drm_printf(p, "\ttail (memory): %d\n", snapshot->desc.tail);
> +	drm_printf(p, "\tstatus (memory): 0x%x\n", snapshot->desc.status);
> +
> +	head = snapshot->desc.head;
> +	tail = snapshot->desc.tail;
> +
> +	while (head != tail) {
> +		drm_printf(p, "\tcmd[%d]: 0x%08x\n", head,
> +			   snapshot->cmds[head]);
> +		++head;
> +		if (head == snapshot->info.size)
> +			head = 0;
> +	}
> +}
> +
> +static void guc_ctb_snapshot_free(struct guc_ctb_snapshot *snapshot)
> +{
> +	kfree(snapshot->cmds);
> +}
> +
> +/**
> + * xe_guc_ct_snapshot_capture - Take a quick snapshot of the CT state.
> + * @ct: GuC CT object.
> + *
> + * This can be printed out in a later stage like during dev_coredump
> + * analysis.
> + *
> + * Returns: a GuC CT snapshot object that must be freed by the caller
> + * 	    by using `xe_guc_ct_snapshot_free`.
> + */
> +struct xe_guc_ct_snapshot *xe_guc_ct_snapshot_capture(struct xe_guc_ct *ct)
>  {
> +	struct xe_guc_ct_snapshot *snapshot;
> +
> +	snapshot = kzalloc(sizeof(struct xe_guc_ct_snapshot), GFP_ATOMIC);
> +

Same here, need to check for an alloc failure.

Also maybe we should a flag to switch between GFP_ATOMIC (signaling
path) and GFP_KERNEL (debugfs). In the case above, CMDs might be huge as
deadlock workaround (like 16 MBs or something) so atomic seems risky.

Aside from these comments, I do rather like what you have done here.

Matt

>  	if (ct->enabled) {
> +		snapshot->ct_enabled = true;
> +		guc_ctb_snapshot_capture(ct_to_xe(ct), &ct->ctbs.h2g,
> +					 &snapshot->h2g);
> +		guc_ctb_snapshot_capture(ct_to_xe(ct), &ct->ctbs.g2h,
> +					 &snapshot->g2h);
> +	}
> +
> +	return snapshot;
> +}
> +
> +/**
> + * xe_guc_ct_snapshot_print - Print out a given GuC CT snapshot.
> + * @snapshot: GuC CT snapshot object.
> + * @p: drm_printer where it will be printed out.
> + *
> + * This function prints out a given GuC CT snapshot object.
> + */
> +void xe_guc_ct_snapshot_print(struct xe_guc_ct_snapshot *snapshot,
> +			      struct drm_printer *p)
> +{
> +	if (snapshot->ct_enabled) {
>  		drm_puts(p, "\nH2G CTB (all sizes in DW):\n");
> -		guc_ct_ctb_print(ct_to_xe(ct), &ct->ctbs.h2g, p);
> +		guc_ctb_snapshot_print(&snapshot->h2g, p);
>  
>  		drm_puts(p, "\nG2H CTB (all sizes in DW):\n");
> -		guc_ct_ctb_print(ct_to_xe(ct), &ct->ctbs.g2h, p);
> -		drm_printf(p, "\tg2h outstanding: %d\n", ct->g2h_outstanding);
> +		guc_ctb_snapshot_print(&snapshot->g2h, p);
> +
> +		drm_printf(p, "\tg2h outstanding: %d\n",
> +			   snapshot->g2h_outstanding);
>  	} else {
>  		drm_puts(p, "\nCT disabled\n");
>  	}
>  }
>  
> +/**
> + * xe_guc_ct_snapshot_free - Free all allocated objects for a given snapshot.
> + * @snapshot: GuC CT snapshot object.
> + *
> + * This function free all the memory that needed to be allocated at capture
> + * time.
> + */
> +void xe_guc_ct_snapshot_free(struct xe_guc_ct_snapshot *snapshot)
> +{
> +	guc_ctb_snapshot_free(&snapshot->h2g);
> +	guc_ctb_snapshot_free(&snapshot->g2h);
> +	kfree(snapshot);
> +}
> +
> +/**
> + * xe_guc_ct_print - GuC CT Print.
> + * @ct: GuC CT.
> + * @p: drm_printer where it will be printed out.
> + *
> + * This function quickly capture a snapshot and immediately print it out.
> + */
> +void xe_guc_ct_print(struct xe_guc_ct *ct, struct drm_printer *p)
> +{
> +	struct xe_guc_ct_snapshot *snapshot;
> +
> +	snapshot = xe_guc_ct_snapshot_capture(ct);
> +	xe_guc_ct_snapshot_print(snapshot, p);
> +	xe_guc_ct_snapshot_free(snapshot);
> +}
> +
>  #ifdef XE_GUC_CT_SELFTEST
>  /*
>   * Disable G2H processing in IRQ handler to force xe_guc_ct_send to enter flow
> diff --git a/drivers/gpu/drm/xe/xe_guc_ct.h b/drivers/gpu/drm/xe/xe_guc_ct.h
> index 49fb74f91e4d..29e0dff7ad9b 100644
> --- a/drivers/gpu/drm/xe/xe_guc_ct.h
> +++ b/drivers/gpu/drm/xe/xe_guc_ct.h
> @@ -13,9 +13,14 @@ struct drm_printer;
>  int xe_guc_ct_init(struct xe_guc_ct *ct);
>  int xe_guc_ct_enable(struct xe_guc_ct *ct);
>  void xe_guc_ct_disable(struct xe_guc_ct *ct);
> -void xe_guc_ct_print(struct xe_guc_ct *ct, struct drm_printer *p);
>  void xe_guc_ct_fast_path(struct xe_guc_ct *ct);
>  
> +struct xe_guc_ct_snapshot *xe_guc_ct_snapshot_capture(struct xe_guc_ct *ct);
> +void xe_guc_ct_snapshot_print(struct xe_guc_ct_snapshot *snapshot,
> +			      struct drm_printer *p);
> +void xe_guc_ct_snapshot_free(struct xe_guc_ct_snapshot *snapshot);
> +void xe_guc_ct_print(struct xe_guc_ct *ct, struct drm_printer *p);
> +
>  static inline void xe_guc_ct_irq_handler(struct xe_guc_ct *ct)
>  {
>  	wake_up_all(&ct->wq);
> diff --git a/drivers/gpu/drm/xe/xe_guc_ct_types.h b/drivers/gpu/drm/xe/xe_guc_ct_types.h
> index 64e3dd14d4b2..93046d95b009 100644
> --- a/drivers/gpu/drm/xe/xe_guc_ct_types.h
> +++ b/drivers/gpu/drm/xe/xe_guc_ct_types.h
> @@ -48,6 +48,32 @@ struct guc_ctb {
>  	struct guc_ctb_info info;
>  };
>  
> +/**
> + * struct guc_ctb_snapshot - GuC command transport buffer (CTB) snapshot
> + */
> +struct guc_ctb_snapshot {
> +	/** @desc: snapshot of the CTB descriptor */
> +	struct guc_ct_buffer_desc desc;
> +	/** @cmds: snapshot of the CTB commands */
> +	u32 *cmds;
> +	/** @info: snapshot of the CTB info */
> +	struct guc_ctb_info info;
> +};
> +
> +/**
> + * struct xe_guc_ct_snapshot - GuC command transport (CT) snapshot
> + */
> +struct xe_guc_ct_snapshot {
> +	/** @ct_enabled: CT enabled info at capture time. */
> +	bool ct_enabled;
> +	/** @g2h_outstanding: G2H outstanding info at the capture time */
> +	u32 g2h_outstanding;
> +	/** @g2h: G2H CTB snapshot */
> +	struct guc_ctb_snapshot g2h;
> +	/** @h2g: H2G CTB snapshot */
> +	struct guc_ctb_snapshot h2g;
> +};
> +
>  /**
>   * struct xe_guc_ct - GuC command transport (CT) layer
>   *
> -- 
> 2.39.2
> 

  reply	other threads:[~2023-05-02  5:27 UTC|newest]

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-04-26 20:56 [Intel-xe] [PATCH 00/14] Introduce xe_devcoredump Rodrigo Vivi
2023-04-26 20:57 ` [Intel-xe] [PATCH 01/14] drm/xe: Fix print of RING_EXECLIST_SQ_CONTENTS_HI Rodrigo Vivi
2023-04-26 21:40   ` Lucas De Marchi
2023-04-26 21:59     ` Rodrigo Vivi
2023-04-26 20:57 ` [Intel-xe] [PATCH 02/14] drm/xe: Introduce the dev_coredump infrastructure Rodrigo Vivi
2023-04-27  8:28   ` Thomas Hellström
2023-05-02  7:57     ` Matthew Brost
2023-05-02 18:06       ` Rodrigo Vivi
2023-05-02 20:29         ` Matthew Brost
2023-05-02  7:55   ` Jani Nikula
2023-05-02 17:25     ` Rodrigo Vivi
2023-04-26 20:57 ` [Intel-xe] [PATCH 03/14] drm/xe: Do not take any action if our device was removed Rodrigo Vivi
2023-05-02 15:40   ` Matthew Brost
2023-05-02 17:21     ` Rodrigo Vivi
2023-05-02 23:06       ` Matthew Brost
2023-04-26 20:57 ` [Intel-xe] [PATCH 04/14] drm/xe: Extract non mapped regions out of GuC CTB into its own struct Rodrigo Vivi
2023-05-02  5:12   ` Matthew Brost
2023-04-26 20:57 ` [Intel-xe] [PATCH 05/14] drm/xe: Convert GuC CT print to snapshot capture and print Rodrigo Vivi
2023-05-02  5:27   ` Matthew Brost [this message]
2023-04-26 20:57 ` [Intel-xe] [PATCH 06/14] drm/xe: Add GuC CT snapshot to xe_devcoredump Rodrigo Vivi
2023-05-02 14:55   ` Matthew Brost
2023-04-26 20:57 ` [Intel-xe] [PATCH 07/14] drm/xe: Introduce guc_submit_types.h with relevant structs Rodrigo Vivi
2023-05-02  7:44   ` Matthew Brost
2023-04-26 20:57 ` [Intel-xe] [PATCH 08/14] drm/xe: Convert GuC Engine print to snapshot capture and print Rodrigo Vivi
2023-05-02 15:01   ` Matthew Brost
2023-04-26 20:57 ` [Intel-xe] [PATCH 09/14] drm/xe: Add GuC Submit Engine snapshot to xe_devcoredump Rodrigo Vivi
2023-05-02 15:03   ` Matthew Brost
2023-04-26 20:57 ` [Intel-xe] [PATCH 10/14] drm/xe: Convert Xe HW Engine print to snapshot capture and print Rodrigo Vivi
2023-05-02 15:20   ` Matthew Brost
2023-04-26 20:57 ` [Intel-xe] [PATCH 11/14] drm/xe: Add HW Engine snapshot to xe_devcoredump Rodrigo Vivi
2023-05-02 15:30   ` Matthew Brost
2023-04-26 20:57 ` [Intel-xe] [PATCH 12/14] drm/xe: Limit CONFIG_DRM_XE_SIMPLE_ERROR_CAPTURE to itself Rodrigo Vivi
2023-05-02 15:35   ` Matthew Brost
2023-04-26 20:57 ` [Intel-xe] [PATCH 13/14] drm/xe: Convert VM print to snapshot capture and print Rodrigo Vivi
2023-05-02  7:50   ` Matthew Brost
2023-05-02  8:07   ` Matthew Brost
2023-04-26 20:57 ` [Intel-xe] [PATCH 14/14] drm/xe: Add VM snapshot to xe_devcoredump Rodrigo Vivi
2023-05-02 15:38   ` Matthew Brost
2023-04-26 21:01 ` [Intel-xe] ✓ CI.Patch_applied: success for Introduce xe_devcoredump Patchwork
2023-04-26 21:02 ` [Intel-xe] ✓ CI.KUnit: " Patchwork
2023-04-26 21:06 ` [Intel-xe] ✓ CI.Build: " Patchwork
2023-04-26 21:29 ` [Intel-xe] ○ CI.BAT: info " Patchwork
2023-05-02  8:11 ` [Intel-xe] [PATCH 00/14] " Matthew Brost

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