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[AMD Official Use Only]<br>
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<p class="MsoNormal">We were seeing process leaks on a couple of machines running certain tests that triggered vm faults on purpose.<o:p></o:p></p>
<p class="MsoNormal">I think svm_range_restore_pages gets called unconditionally on vm fault handling (unless the retry interrupt payload bit is supposed to be clear with xnack off)?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Either way, this patch prevents the process leaks we seeing and is also:<o:p></o:p></p>
<p class="MsoNormal">Reviewed-by: Jonathan Kim <jonathan.kim@amd.com><o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Jon<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><b>From:</b> amd-gfx <amd-gfx-bounces@lists.freedesktop.org>
<b>On Behalf Of </b>philip yang<br>
<b>Sent:</b> Wednesday, September 1, 2021 7:30 AM<br>
<b>To:</b> Sierra Guiza, Alejandro (Alex) <Alex.Sierra@amd.com>; amd-gfx@lists.freedesktop.org<br>
<b>Subject:</b> Re: [PATCH] drm/amdkfd: drop process ref count when xnack disable<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">[CAUTION: External Email] <o:p></o:p></p>
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<p><o:p> </o:p></p>
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<p class="MsoNormal">On 2021-08-31 10:41 p.m., Alex Sierra wrote:<o:p></o:p></p>
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<pre>During svm restore pages interrupt handler, kfd_process ref count was<o:p></o:p></pre>
<pre>never dropped when xnack was disabled. Therefore, the object was never<o:p></o:p></pre>
<pre>released.<o:p></o:p></pre>
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<p>Good catch, but if xnack is off, we should not get here to recover fault.<o:p></o:p></p>
<p>The fix looks good to me.<o:p></o:p></p>
<p>Reviewed-by: Philip Yang <a href="mailto:philip.yang@amd.com"><philip.yang@amd.com></a><o:p></o:p></p>
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<pre><o:p> </o:p></pre>
<pre>Signed-off-by: Alex Sierra <a href="mailto:alex.sierra@amd.com"><alex.sierra@amd.com></a><o:p></o:p></pre>
<pre>---<o:p></o:p></pre>
<pre> drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 3 ++-<o:p></o:p></pre>
<pre> 1 file changed, 2 insertions(+), 1 deletion(-)<o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre>diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c<o:p></o:p></pre>
<pre>index 8f9b5b53dab5..110c46cd7fac 100644<o:p></o:p></pre>
<pre>--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c<o:p></o:p></pre>
<pre>+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c<o:p></o:p></pre>
<pre>@@ -2484,7 +2484,8 @@ svm_range_restore_pages(struct amdgpu_device *adev, unsigned int pasid,<o:p></o:p></pre>
<pre> }<o:p></o:p></pre>
<pre> if (!p->xnack_enabled) {<o:p></o:p></pre>
<pre> pr_debug("XNACK not enabled for pasid 0x%x\n", pasid);<o:p></o:p></pre>
<pre>- return -EFAULT;<o:p></o:p></pre>
<pre>+ r = -EFAULT;<o:p></o:p></pre>
<pre>+ goto out;<o:p></o:p></pre>
<pre> }<o:p></o:p></pre>
<pre> svms = &p->svms;<o:p></o:p></pre>
<pre> <o:p></o:p></pre>
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