[PATCH] drm/amdgpu: Add autodump debugfs node for gpu reset v4

Christian König christian.koenig at amd.com
Fri May 15 06:51:17 UTC 2020


The first application to open the autodump node gets the right to use it.

All others only get -EBUSY until the first application is done with the 
hardware.

Christian.

Am 15.05.20 um 04:40 schrieb Zhao, Jiange:
>
> [AMD Official Use Only - Internal Distribution Only]
>
>
> Hi Dennis,
>
> This node/feature is for UMR extension. It is designed for a single user.
>
> Jiange
> ------------------------------------------------------------------------
> *From:* Li, Dennis <Dennis.Li at amd.com>
> *Sent:* Thursday, May 14, 2020 11:15 PM
> *To:* Koenig, Christian <Christian.Koenig at amd.com>; Zhao, Jiange 
> <Jiange.Zhao at amd.com>; amd-gfx at lists.freedesktop.org 
> <amd-gfx at lists.freedesktop.org>
> *Cc:* Deucher, Alexander <Alexander.Deucher at amd.com>; Pelloux-prayer, 
> Pierre-eric <Pierre-eric.Pelloux-prayer at amd.com>; Kuehling, Felix 
> <Felix.Kuehling at amd.com>; Liu, Monk <Monk.Liu at amd.com>; Zhang, Hawking 
> <Hawking.Zhang at amd.com>
> *Subject:* RE: [PATCH] drm/amdgpu: Add autodump debugfs node for gpu 
> reset v4
>
> [AMD Official Use Only - Internal Distribution Only]
>
> Hi, Jiange,
>
> How to handle the case that multi-apps do the auto dump? This patch 
> seems not multi-process safety.
>
> Best Regards
>
> Dennis Li
>
> *From:*amd-gfx <amd-gfx-bounces at lists.freedesktop.org> *On Behalf Of 
> *Christian König
> *Sent:* Thursday, May 14, 2020 4:29 PM
> *To:* Zhao, Jiange <Jiange.Zhao at amd.com>; amd-gfx at lists.freedesktop.org
> *Cc:* Deucher, Alexander <Alexander.Deucher at amd.com>; Pelloux-prayer, 
> Pierre-eric <Pierre-eric.Pelloux-prayer at amd.com>; Kuehling, Felix 
> <Felix.Kuehling at amd.com>; Liu, Monk <Monk.Liu at amd.com>; Zhang, Hawking 
> <Hawking.Zhang at amd.com>
> *Subject:* Re: [PATCH] drm/amdgpu: Add autodump debugfs node for gpu 
> reset v4
>
> Hi Jiange,
>
> it probably won't hurt, but I would just drop that. You need roughly 4 
> billion GPU resets until the UINT_MAX-1 becomes zero again.
>
> Christian.
>
> Am 14.05.20 um 09:14 schrieb Zhao, Jiange:
>
>     [AMD Official Use Only - Internal Distribution Only]
>
>     Hi Christian,
>
>     wait_for_completion_interruptible_timeout() would decrease
>     autodump.dumping.done to UINT_MAX-1.
>
>     complete_all() here would restore autodump.dumping to the state as
>     in amdgpu_debugfs_autodump_init().
>
>     I want to make sure every open() deals with the same situation.
>
>     Jiange
>
>     ------------------------------------------------------------------------
>
>     *From:* Christian König <ckoenig.leichtzumerken at gmail.com>
>     <mailto:ckoenig.leichtzumerken at gmail.com>
>     *Sent:* Thursday, May 14, 2020 3:01 PM
>     *To:* Zhao, Jiange <Jiange.Zhao at amd.com>
>     <mailto:Jiange.Zhao at amd.com>; amd-gfx at lists.freedesktop.org
>     <mailto:amd-gfx at lists.freedesktop.org>
>     <amd-gfx at lists.freedesktop.org> <mailto:amd-gfx at lists.freedesktop.org>
>     *Cc:* Pelloux-prayer, Pierre-eric
>     <Pierre-eric.Pelloux-prayer at amd.com>
>     <mailto:Pierre-eric.Pelloux-prayer at amd.com>; Zhao, Jiange
>     <Jiange.Zhao at amd.com> <mailto:Jiange.Zhao at amd.com>; Kuehling,
>     Felix <Felix.Kuehling at amd.com> <mailto:Felix.Kuehling at amd.com>;
>     Deucher, Alexander <Alexander.Deucher at amd.com>
>     <mailto:Alexander.Deucher at amd.com>; Koenig, Christian
>     <Christian.Koenig at amd.com> <mailto:Christian.Koenig at amd.com>; Liu,
>     Monk <Monk.Liu at amd.com> <mailto:Monk.Liu at amd.com>; Zhang, Hawking
>     <Hawking.Zhang at amd.com> <mailto:Hawking.Zhang at amd.com>
>     *Subject:* Re: [PATCH] drm/amdgpu: Add autodump debugfs node for
>     gpu reset v4
>
>     Am 14.05.20 um 07:29 schrieb jianzh at amd.com <mailto:jianzh at amd.com>:
>     > From: Jiange Zhao <Jiange.Zhao at amd.com> <mailto:Jiange.Zhao at amd.com>
>     >
>     > When GPU got timeout, it would notify an interested part
>     > of an opportunity to dump info before actual GPU reset.
>     >
>     > A usermode app would open 'autodump' node under debugfs system
>     > and poll() for readable/writable. When a GPU reset is due,
>     > amdgpu would notify usermode app through wait_queue_head and give
>     > it 10 minutes to dump info.
>     >
>     > After usermode app has done its work, this 'autodump' node is
>     closed.
>     > On node closure, amdgpu gets to know the dump is done through
>     > the completion that is triggered in release().
>     >
>     > There is no write or read callback because necessary info can be
>     > obtained through dmesg and umr. Messages back and forth between
>     > usermode app and amdgpu are unnecessary.
>     >
>     > v2: (1) changed 'registered' to 'app_listening'
>     >      (2) add a mutex in open() to prevent race condition
>     >
>     > v3 (chk): grab the reset lock to avoid race in autodump_open,
>     >            rename debugfs file to amdgpu_autodump,
>     >            provide autodump_read as well,
>     >            style and code cleanups
>     >
>     > v4: add 'bool app_listening' to differentiate situations, so that
>     >      the node can be reopened; also, there is no need to wait for
>     >      completion when no app is waiting for a dump.
>     >
>     > v5: change 'bool app_listening' to 'enum amdgpu_autodump_state'
>     >      add 'app_state_mutex' for race conditions:
>     >        (1)Only 1 user can open this file node
>     >        (2)wait_dump() can only take effect after poll() executed.
>     >        (3)eliminated the race condition between release() and
>     >           wait_dump()
>     >
>     > v6: removed 'enum amdgpu_autodump_state' and 'app_state_mutex'
>     >      removed state checking in amdgpu_debugfs_wait_dump
>     >      Improve on top of version 3 so that the node can be reopened.
>     >
>     > v7: move reinit_completion into open() so that only one user
>     >      can open it.
>     >
>     > Signed-off-by: Jiange Zhao <Jiange.Zhao at amd.com>
>     <mailto:Jiange.Zhao at amd.com>
>     > ---
>     >   drivers/gpu/drm/amd/amdgpu/amdgpu.h |  2 +
>     >   drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 79
>     ++++++++++++++++++++-
>     >   drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.h |  6 ++
>     >   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c |  2 +
>     >   4 files changed, 88 insertions(+), 1 deletion(-)
>     >
>     > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>     b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>     > index 2a806cb55b78..9e8eeddfe7ce 100644
>     > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>     > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>     > @@ -992,6 +992,8 @@ struct amdgpu_device {
>     >        char product_number[16];
>     >        char product_name[32];
>     >        char serial[16];
>     > +
>     > +     struct amdgpu_autodump autodump;
>     >   };
>     >
>     >   static inline struct amdgpu_device *amdgpu_ttm_adev(struct
>     ttm_bo_device *bdev)
>     > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
>     b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
>     > index 1a4894fa3693..efee3f1adecf 100644
>     > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
>     > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
>     > @@ -27,7 +27,7 @@
>     >   #include <linux/pci.h>
>     >   #include <linux/uaccess.h>
>     >   #include <linux/pm_runtime.h>
>     > -
>     > +#include <linux/poll.h>
>     >   #include <drm/drm_debugfs.h>
>     >
>     >   #include "amdgpu.h"
>     > @@ -74,8 +74,83 @@ int amdgpu_debugfs_add_files(struct
>     amdgpu_device *adev,
>     >        return 0;
>     >   }
>     >
>     > +int amdgpu_debugfs_wait_dump(struct amdgpu_device *adev)
>     > +{
>     > +#if defined(CONFIG_DEBUG_FS)
>     > +     unsigned long timeout = 600 * HZ;
>     > +     int ret;
>     > +
>     > + wake_up_interruptible(&adev->autodump.gpu_hang);
>     > +
>     > +     ret =
>     wait_for_completion_interruptible_timeout(&adev->autodump.dumping,
>     timeout);
>     > + complete_all(&adev->autodump.dumping);
>
>     Sorry that I'm mentioning this only now. But what is this
>     complete_all()
>     here good for?
>
>     I mean we already waited for completion, didn't we?
>
>     Christian.
>
>     > +     if (ret == 0) {
>     > +             pr_err("autodump: timeout, move on to gpu
>     recovery\n");
>     > +             return -ETIMEDOUT;
>     > +     }
>     > +#endif
>     > +     return 0;
>     > +}
>     > +
>     >   #if defined(CONFIG_DEBUG_FS)
>     >
>     > +static int amdgpu_debugfs_autodump_open(struct inode *inode,
>     struct file *file)
>     > +{
>     > +     struct amdgpu_device *adev = inode->i_private;
>     > +     int ret;
>     > +
>     > +     file->private_data = adev;
>     > +
>     > +     mutex_lock(&adev->lock_reset);
>     > +     if (adev->autodump.dumping.done) {
>     > + reinit_completion(&adev->autodump.dumping);
>     > +             ret = 0;
>     > +     } else {
>     > +             ret = -EBUSY;
>     > +     }
>     > +     mutex_unlock(&adev->lock_reset);
>     > +
>     > +     return ret;
>     > +}
>     > +
>     > +static int amdgpu_debugfs_autodump_release(struct inode *inode,
>     struct file *file)
>     > +{
>     > +     struct amdgpu_device *adev = file->private_data;
>     > +
>     > + complete_all(&adev->autodump.dumping);
>     > +     return 0;
>     > +}
>     > +
>     > +static unsigned int amdgpu_debugfs_autodump_poll(struct file
>     *file, struct poll_table_struct *poll_table)
>     > +{
>     > +     struct amdgpu_device *adev = file->private_data;
>     > +
>     > +     poll_wait(file, &adev->autodump.gpu_hang, poll_table);
>     > +
>     > +     if (adev->in_gpu_reset)
>     > +             return POLLIN | POLLRDNORM | POLLWRNORM;
>     > +
>     > +     return 0;
>     > +}
>     > +
>     > +static const struct file_operations autodump_debug_fops = {
>     > +     .owner = THIS_MODULE,
>     > +     .open = amdgpu_debugfs_autodump_open,
>     > +     .poll = amdgpu_debugfs_autodump_poll,
>     > +     .release = amdgpu_debugfs_autodump_release,
>     > +};
>     > +
>     > +static void amdgpu_debugfs_autodump_init(struct amdgpu_device
>     *adev)
>     > +{
>     > + init_completion(&adev->autodump.dumping);
>     > + complete_all(&adev->autodump.dumping);
>     > + init_waitqueue_head(&adev->autodump.gpu_hang);
>     > +
>     > +     debugfs_create_file("amdgpu_autodump", 0600,
>     > + adev->ddev->primary->debugfs_root,
>     > +             adev, &autodump_debug_fops);
>     > +}
>     > +
>     >   /**
>     >    * amdgpu_debugfs_process_reg_op - Handle MMIO register
>     reads/writes
>     >    *
>     > @@ -1434,6 +1509,8 @@ int amdgpu_debugfs_init(struct
>     amdgpu_device *adev)
>     >
>     >        amdgpu_ras_debugfs_create_all(adev);
>     >
>     > +     amdgpu_debugfs_autodump_init(adev);
>     > +
>     >        return amdgpu_debugfs_add_files(adev, amdgpu_debugfs_list,
>     > ARRAY_SIZE(amdgpu_debugfs_list));
>     >   }
>     > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.h
>     b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.h
>     > index de12d1101526..2803884d338d 100644
>     > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.h
>     > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.h
>     > @@ -31,6 +31,11 @@ struct amdgpu_debugfs {
>     >        unsigned                num_files;
>     >   };
>     >
>     > +struct amdgpu_autodump {
>     > +     struct completion dumping;
>     > +     struct wait_queue_head gpu_hang;
>     > +};
>     > +
>     >   int amdgpu_debugfs_regs_init(struct amdgpu_device *adev);
>     >   int amdgpu_debugfs_init(struct amdgpu_device *adev);
>     >   void amdgpu_debugfs_fini(struct amdgpu_device *adev);
>     > @@ -40,3 +45,4 @@ int amdgpu_debugfs_add_files(struct
>     amdgpu_device *adev,
>     >   int amdgpu_debugfs_fence_init(struct amdgpu_device *adev);
>     >   int amdgpu_debugfs_firmware_init(struct amdgpu_device *adev);
>     >   int amdgpu_debugfs_gem_init(struct amdgpu_device *adev);
>     > +int amdgpu_debugfs_wait_dump(struct amdgpu_device *adev);
>     > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>     b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>     > index cc41e8f5ad14..545beebcf43e 100644
>     > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>     > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>     > @@ -3927,6 +3927,8 @@ static int
>     amdgpu_device_pre_asic_reset(struct amdgpu_device *adev,
>     >        int i, r = 0;
>     >        bool need_full_reset  = *need_full_reset_arg;
>     >
>     > +     amdgpu_debugfs_wait_dump(adev);
>     > +
>     >        /* block all schedulers and reset given job's ring */
>     >        for (i = 0; i < AMDGPU_MAX_RINGS; ++i) {
>     >                struct amdgpu_ring *ring = adev->rings[i];
>

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