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Am 20.04.22 um 14:54 schrieb Wang, Yang(Kevin):<br>
<blockquote type="cite" cite="mid:CO6PR12MB547334A5A8E66A578D131C6D82F59@CO6PR12MB5473.namprd12.prod.outlook.com">
<style type="text/css" style="display:none;">P {margin-top:0;margin-bottom:0;}</style>
<p style="font-family:Arial;font-size:10pt;color:#0000FF;margin:5pt;" align="Left">
[AMD Official Use Only]<br>
</p>
<br>
<div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif;
font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
<span style="font-family: "Segoe UI", "Segoe UI
Web (West European)", "Segoe UI",
-apple-system, BlinkMacSystemFont, Roboto, "Helvetica
Neue", sans-serif; font-size: 10.5pt; background-color:
rgb(255, 255, 255); display: inline !important; color:
rgb(0, 0, 0);" class="elementToProof">Hi Chris,</span></div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif;
font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
<span style="font-family: "Segoe UI", "Segoe UI
Web (West European)", "Segoe UI",
-apple-system, BlinkMacSystemFont, Roboto, "Helvetica
Neue", sans-serif; font-size: 10.5pt; background-color:
rgb(255, 255, 255); display: inline !important; color:
rgb(0, 0, 0);"><br>
</span></div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif;
font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
<span style="font-family: "Segoe UI", "Segoe UI
Web (West European)", "Segoe UI",
-apple-system, BlinkMacSystemFont, Roboto, "Helvetica
Neue", sans-serif; font-size: 10.5pt; background-color:
rgb(255, 255, 255); display: inline !important; color:
rgb(0, 0, 0);">1) Change the test case to use something
larger than 1TiB.</span></div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif;
font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
<span style="font-family: "Segoe UI", "Segoe UI
Web (West European)", "Segoe UI",
-apple-system, BlinkMacSystemFont, Roboto, "Helvetica
Neue", sans-serif; font-size: 10.5pt; color: rgb(0, 0,
0); background-color: rgb(255, 255, 255);">sure, we can
increase the size of BO and make test pass,</span></div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif;
font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
<span style="font-family: "Segoe UI", "Segoe UI
Web (West European)", "Segoe UI",
-apple-system, BlinkMacSystemFont, Roboto, "Helvetica
Neue", sans-serif; font-size: 10.5pt; color: rgb(0, 0,
0); background-color: rgb(255, 255, 255);">but if user
really want to allocate 1TB GTT BO, we have no reason to let
it fail? right? <br>
</span></div>
</div>
</blockquote>
<br>
No, the reason is the underlying core kernel doesn't allow kvmalloc
allocations with GFP_ZERO which are large enough to hold the array
of allocated pages for this.<br>
<br>
We are working on top of the core Linux kernel and should *NEVER*
ever add workarounds like what was suggested here.<br>
<br>
Regards,<br>
Christian.<br>
<br>
<blockquote type="cite" cite="mid:CO6PR12MB547334A5A8E66A578D131C6D82F59@CO6PR12MB5473.namprd12.prod.outlook.com">
<div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif;
font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
<span style="font-family: "Segoe UI", "Segoe UI
Web (West European)", "Segoe UI",
-apple-system, BlinkMacSystemFont, Roboto, "Helvetica
Neue", sans-serif; font-size: 10.5pt; color: rgb(0, 0,
0); background-color: rgb(255, 255, 255);">the system
availed memory about 2T, but it will still fail.</span></div>
<div style="color: rgb(0, 0, 0);" class="elementToProof"><font face="Calibri, Arial, Helvetica, sans-serif"><br style="background-color: rgb(255, 255, 255);">
</font></div>
<div style="color: rgb(0, 0, 0);" class="elementToProof"><span style="font-family: "Segoe UI", "Segoe UI Web
(West European)", "Segoe UI", -apple-system,
BlinkMacSystemFont, Roboto, "Helvetica Neue",
sans-serif; font-size: 14px; background-color: rgb(255, 255,
255); display: inline !important;">2) Change kvmalloc to
allow GFP_ZERO allocations even in the vmalloc fallback
path.</span></div>
<div style="color: rgb(0, 0, 0);" class="elementToProof"><span style="font-family: "Segoe UI", "Segoe UI Web
(West European)", "Segoe UI", -apple-system,
BlinkMacSystemFont, Roboto, "Helvetica Neue",
sans-serif; font-size: 14px; background-color: rgb(255, 255,
255); display: inline !important;"> the 5.18 kernel will
add this patch to fix this issue .</span></div>
<div style="color: rgb(0, 0, 0);" class="elementToProof"><span style="font-family: "Segoe UI", "Segoe UI Web
(West European)", "Segoe UI", -apple-system,
BlinkMacSystemFont, Roboto, "Helvetica Neue",
sans-serif; font-size: 14px; background-color: rgb(255, 255,
255); display: inline !important;"><br>
</span></div>
<div style="color: rgb(0, 0, 0);" class="elementToProof"><span style="font-family: "Segoe UI", "Segoe UI Web
(West European)", "Segoe UI", -apple-system,
BlinkMacSystemFont, Roboto, "Helvetica Neue",
sans-serif; font-size: 14px; background-color: rgb(255, 255,
255); display: inline !important;">Best Regards,</span></div>
<div style="color: rgb(0, 0, 0);" class="elementToProof"><span style="font-family: "Segoe UI", "Segoe UI Web
(West European)", "Segoe UI", -apple-system,
BlinkMacSystemFont, Roboto, "Helvetica Neue",
sans-serif; font-size: 14px; background-color: rgb(255, 255,
255); display: inline !important;">Kevin</span></div>
<hr tabindex="-1" style="display:inline-block; width:98%">
<div id="divRplyFwdMsg" dir="ltr"><font style="font-size:11pt" face="Calibri, sans-serif" color="#000000"><b>From:</b>
Koenig, Christian <a class="moz-txt-link-rfc2396E" href="mailto:Christian.Koenig@amd.com"><Christian.Koenig@amd.com></a><br>
<b>Sent:</b> Wednesday, April 20, 2022 8:42 PM<br>
<b>To:</b> Wang, Yang(Kevin) <a class="moz-txt-link-rfc2396E" href="mailto:KevinYang.Wang@amd.com"><KevinYang.Wang@amd.com></a>;
Christian König <a class="moz-txt-link-rfc2396E" href="mailto:ckoenig.leichtzumerken@gmail.com"><ckoenig.leichtzumerken@gmail.com></a>;
<a class="moz-txt-link-abbreviated" href="mailto:dri-devel@lists.freedesktop.org">dri-devel@lists.freedesktop.org</a>
<a class="moz-txt-link-rfc2396E" href="mailto:dri-devel@lists.freedesktop.org"><dri-devel@lists.freedesktop.org></a>;
<a class="moz-txt-link-abbreviated" href="mailto:amd-gfx@lists.freedesktop.org">amd-gfx@lists.freedesktop.org</a>
<a class="moz-txt-link-rfc2396E" href="mailto:amd-gfx@lists.freedesktop.org"><amd-gfx@lists.freedesktop.org></a><br>
<b>Subject:</b> Re: [PATCH] drm/ttm: fix ttm tt init fail
when size exceeds kmalloc limit</font>
<div> </div>
</div>
<div class="elementToProof">Hi Kevin,<br>
<br>
yes and that is perfectly valid and expected behavior. There
is absolutely no need to change anything in TTM here.<br>
<br>
What we could do is:<br>
1) Change the test case to use something larger than 1TiB.<br>
2) Change kvmalloc to allow GFP_ZERO allocations even in the
vmalloc fallback path.<br>
<br>
Regards,<br>
Christian.<br>
<br>
<div class="x_moz-cite-prefix">Am 20.04.22 um 14:39 schrieb
Wang, Yang(Kevin):<br>
</div>
<blockquote type="cite">
<p style="margin-top: 0px; margin-bottom:
0px;font-family:Arial; font-size:10pt; color:#0000FF;
margin:5pt" align="Left">
[AMD Official Use Only]<br>
</p>
<br>
<div>
<div class="x_elementToProof" style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0)">
<span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0);
background-color:rgba(0,0,0,0)">Hi Chirs,</span></div>
<div class="x_elementToProof" style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div class="x_elementToProof" style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0)">
<span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0);
background-color:rgba(0,0,0,0)">yes, right, the amdgpu
drive rwill use </span><span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; background-color:rgba(0,0,0,0);
color:rgb(0,0,0); display:inline!important">amdgpu_bo_validate_size()
function to verify bo size,</span></div>
<div class="x_elementToProof" style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0)">
<span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; background-color:rgba(0,0,0,0);
display:inline!important; color:rgb(0,0,0)">but when
driver try to allocate VRAM domain bo fail, the amdgpu
driver will fall back to allocate domain = (GTT |
VRAM) bo.</span></div>
<div class="x_elementToProof" style="font-family:Calibri,Arial,Helvetica,sans-serif;
color:rgb(0,0,0)">
<span style="font-size:12pt;
font-family:Calibri,Arial,Helvetica,sans-serif;
background-color:rgba(0,0,0,0);
display:inline!important; color:rgb(0,0,0)">please
check following code, it will cause the 2</span><span style="font-family:Calibri,Arial,Helvetica,sans-serif;
background-color:rgba(0,0,0,0); color:rgb(0,0,0);
display:inline!important"><span style="font-size:13.3333px">nd time</span><span style="font-size:12pt"> to allocate bo fail during
allocate 256Mb buffer to store dma address (via
kvmalloc()).</span></span></div>
<div class="x_elementToProof" style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0)">
<span style=""><br>
</span></div>
<div class="x_elementToProof" style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0)">
<span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; background-color:rgba(0,0,0,0);
display:inline!important; color:rgb(0,0,0)">
initial_domain = (u32)(0xffffffff &
args->in.domains);</span><span style="">
<div><span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0);
background-color:rgba(0,0,0,0)">retry:</span></div>
<div><span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0);
background-color:rgba(0,0,0,0)"> r =
amdgpu_gem_object_create(adev, size,
args->in.alignment,</span></div>
<div><span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0);
background-color:rgba(0,0,0,0)">
initial_domain,</span></div>
<div><span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0);
background-color:rgba(0,0,0,0)">
flags, ttm_bo_type_device,
resv, &gobj);</span></div>
<div><span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0);
background-color:rgba(0,0,0,0)"> if (r
&& r != -ERESTARTSYS) {</span></div>
<div><span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0);
background-color:rgba(0,0,0,0)"> if
(flags &
AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED) {</span></div>
<div><span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0);
background-color:rgba(0,0,0,0)">
flags &=
~AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED;</span></div>
<div><span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0);
background-color:rgba(0,0,0,0)">
goto retry;</span></div>
<div><span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0);
background-color:rgba(0,0,0,0)"> }</span></div>
<div><br>
</div>
<div><span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0);
background-color:rgba(0,0,0,0)"> if
(initial_domain == AMDGPU_GEM_DOMAIN_VRAM) {</span></div>
<div><span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0);
background-color:rgba(0,0,0,0)">
initial_domain |= AMDGPU_GEM_DOMAIN_GTT;</span></div>
<div><span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0);
background-color:rgba(0,0,0,0)">
goto retry;</span></div>
<div><span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0);
background-color:rgba(0,0,0,0)"> }</span></div>
<div><span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0);
background-color:rgba(0,0,0,0)">
DRM_DEBUG("Failed to allocate GEM object (%llu,
%d, %llu, %d)\n",</span></div>
<div><span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0);
background-color:rgba(0,0,0,0)">
size, initial_domain,
args->in.alignment, r);</span></div>
</span><span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; background-color:rgba(0,0,0,0);
display:inline!important; color:rgb(0,0,0)"> }</span><span style=""><br>
</span></div>
<div class="x_elementToProof" style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div class="x_elementToProof" style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0)">
<span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0);
background-color:rgba(0,0,0,0)">Best Regards,</span></div>
<div class="x_elementToProof" style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0)">
<span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0);
background-color:rgba(0,0,0,0)">Kevin</span></div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<hr tabindex="-1" style="display:inline-block; width:98%">
<div id="x_divRplyFwdMsg" dir="ltr"><font style="font-size:11pt" face="Calibri, sans-serif" color="#000000"><b>From:</b> Christian König
<a href="mailto:ckoenig.leichtzumerken@gmail.com" data-auth="NotApplicable" class="x_moz-txt-link-rfc2396E" moz-do-not-send="true">
<ckoenig.leichtzumerken@gmail.com></a><br>
<b>Sent:</b> Wednesday, April 20, 2022 7:55 PM<br>
<b>To:</b> Wang, Yang(Kevin) <a href="mailto:KevinYang.Wang@amd.com" data-auth="NotApplicable" class="x_moz-txt-link-rfc2396E" moz-do-not-send="true">
<KevinYang.Wang@amd.com></a>; Koenig,
Christian <a href="mailto:Christian.Koenig@amd.com" data-auth="NotApplicable" class="x_moz-txt-link-rfc2396E" moz-do-not-send="true">
<Christian.Koenig@amd.com></a>; <a href="mailto:dri-devel@lists.freedesktop.org" data-auth="NotApplicable" class="x_moz-txt-link-abbreviated
moz-txt-link-freetext" moz-do-not-send="true">
dri-devel@lists.freedesktop.org</a> <a href="mailto:dri-devel@lists.freedesktop.org" data-auth="NotApplicable" class="x_moz-txt-link-rfc2396E" moz-do-not-send="true">
<dri-devel@lists.freedesktop.org></a>; <a href="mailto:amd-gfx@lists.freedesktop.org" data-auth="NotApplicable" class="x_moz-txt-link-abbreviated
moz-txt-link-freetext" moz-do-not-send="true">
amd-gfx@lists.freedesktop.org</a> <a href="mailto:amd-gfx@lists.freedesktop.org" data-auth="NotApplicable" class="x_moz-txt-link-rfc2396E" moz-do-not-send="true">
<amd-gfx@lists.freedesktop.org></a><br>
<b>Subject:</b> Re: [PATCH] drm/ttm: fix ttm tt init
fail when size exceeds kmalloc limit</font>
<div> </div>
</div>
<div class="x_elementToProof">Hi Kevin,<br>
<br>
no, the test case should already fail in
amdgpu_bo_validate_size().<br>
<br>
If we have a system with 2TiB of memory where the test
case could succeed then we should increase the requested
size to something larger.<br>
<br>
And if the underlying core Linux kernel functions don't
allow allocations as large as the requested one we
should *NEVER* ever add workarounds like this.<br>
<br>
It is perfectly expected that this test case is not able
to fulfill the desired allocation. That it fails during
kvmalloc is unfortunate, but not a show stopper.<br>
<br>
Regards,<br>
Christian.<br>
<br>
<br>
<div class="x_x_moz-cite-prefix">Am 20.04.22 um 13:32
schrieb Wang, Yang(Kevin):<br>
</div>
<blockquote type="cite">
<p style="margin-top: 0px; margin-bottom:
0px;margin-top:0px; margin-bottom:0px;
font-family:Arial; font-size:10pt; color:#0000FF;
margin:5pt" align="Left">
[AMD Official Use Only]<br>
</p>
<br>
<div>
<div class="x_x_elementToProof" style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0)">
<span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0);
background-color:rgba(0,0,0,0)">Hi Chris,</span></div>
<div class="x_x_elementToProof" style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div class="x_x_elementToProof" style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0)">
<span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0);
background-color:rgba(0,0,0,0)">you
misunderstood background about this case.</span></div>
<div class="x_x_elementToProof" style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0)">
<span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0);
background-color:rgba(0,0,0,0)"><br>
</span></div>
<div class="x_x_elementToProof" style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0)">
<span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0);
background-color:rgba(0,0,0,0)">a</span><span style="color:rgb(0,0,0);
font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; background-color:rgba(0,0,0,0)">lthough
we expect this test case to fail, it should fail
at the location where the Bo actual memory is
actually allocated. now the code logic will
cause the failure to allocate memory to store
DMA address.</span></div>
<div class="x_x_elementToProof" style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0)">
<span style="color:rgb(0,0,0);
font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; background-color:rgba(0,0,0,0)"><br>
</span></div>
<div class="x_x_elementToProof" style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0)">
<span style="color:rgb(0,0,0);
font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; background-color:rgba(0,0,0,0)"><span style="background-color:rgb(255,255,255);
display:inline!important">e.g: </span>the case
is failed in 2TB system ram machine, it should
be allocated successful, but it is failed.</span></div>
<div class="x_x_elementToProof" style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0)">
<span style="color:rgb(0,0,0);
font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt"><br>
</span></div>
<div class="x_x_elementToProof" style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0)">
<span style="color:rgb(0,0,0);
font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; background-color:rgba(0,0,0,0)">allocate
1TB BO, the ttm should allocate 1TB/4k * 8
buffer to store allocate result (page address),
this should not be failed usually.</span></div>
<div class="x_x_elementToProof" style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0)">
<span style="color:rgb(0,0,0); font-size:12pt;
background-color:rgba(0,0,0,0);
font-family:Calibri,Arial,Helvetica,sans-serif"><br>
</span></div>
<div class="x_x_elementToProof" style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0)">
<span style="color:rgb(0,0,0); font-size:12pt;
background-color:rgba(0,0,0,0);
font-family:Calibri,Arial,Helvetica,sans-serif">There
is a similar fix in upstream kernel 5.18, b</span><span style="color:rgb(0,0,0); font-size:12pt;
background-color:rgba(0,0,0,0);
font-family:Calibri,Arial,Helvetica,sans-serif">efore
this fix entered the TTM code, this problem
existed in TTM.</span></div>
<div class="x_x_elementToProof" style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0)">
<span style="color:rgb(0,0,0); font-size:12pt;
background-color:rgba(0,0,0,0);
font-family:Calibri,Arial,Helvetica,sans-serif"><br>
</span></div>
<div class="x_x_elementToProof" style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0)">
<span style="color:rgb(0,0,0); font-size:12pt;
background-color:rgba(0,0,0,0);
font-family:Calibri,Arial,Helvetica,sans-serif"><a href="https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%2Fcommit%2F%3Fh%3Dv5.18-rc3%26id%3Da421ef303008b0ceee2cfc625c3246fa7654b0ca&data=05%7C01%7CKevinYang.Wang%40amd.com%7C2e9fd86a27d64a39432508da22c4b1f1%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637860525454702938%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=CiP9x3grwQ2aXFZPjpsAtwLCpBVeJufbGngy%2BtXLFbM%3D&reserved=0" data-auth="Verified" originalsrc="https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v5.18-rc3&id=a421ef303008b0ceee2cfc625c3246fa7654b0ca" shash="KMFRekIa5um9dneRj4pqsGBn2wIcYBwLUel6we5AalD06U/g9WcKPxBwS4F9Mgfpnqpq0GbN+8AA16pzy6v+Ay23e5shnO53IP8e7UcwQUE0fw1Wd4T+gBBF8PJiMugXDZiWlVYrV3tySgoFbmz+CuFzrYJbobUVj6E5khawPfo=" id="LPlnk660272" moz-do-not-send="true">kernel/git/torvalds/linux.git
- Linux kernel source tree</a><br>
</span></div>
<div class="x_x_elementToProof" style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0)">
<span class="x_x_commit-subject" style="font-size:12pt; margin:1.5em 0em 0.5em;
padding:0em; color:rgb(0,0,0);
font-family:Calibri,Arial,Helvetica,sans-serif;
background-color:rgb(255,255,255)">mm: allow
!GFP_KERNEL allocations for kvmalloc</span><br>
</div>
<div class="x_x_elementToProof" style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0)">
<div><br>
</div>
<span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0);
background-color:rgba(0,0,0,0)">Best Regards,</span></div>
<div class="x_x_elementToProof" style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0)">
<span style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0);
background-color:rgba(0,0,0,0)">Kevin</span><br>
<div><br>
</div>
</div>
<hr tabindex="-1" style="display:inline-block;
width:98%">
<div id="x_x_divRplyFwdMsg" dir="ltr"><font style="font-size:11pt" face="Calibri,
sans-serif" color="#000000"><b>From:</b> Koenig,
Christian
<a href="mailto:Christian.Koenig@amd.com" data-auth="NotApplicable" class="x_x_moz-txt-link-rfc2396E" moz-do-not-send="true">
<Christian.Koenig@amd.com></a><br>
<b>Sent:</b> Wednesday, April 20, 2022 6:53 PM<br>
<b>To:</b> Wang, Yang(Kevin) <a href="mailto:KevinYang.Wang@amd.com" data-auth="NotApplicable" class="x_x_moz-txt-link-rfc2396E" moz-do-not-send="true">
<KevinYang.Wang@amd.com></a>; <a href="mailto:dri-devel@lists.freedesktop.org" data-auth="NotApplicable" class="x_x_moz-txt-link-abbreviated
x_moz-txt-link-freetext moz-txt-link-freetext" moz-do-not-send="true">
dri-devel@lists.freedesktop.org</a> <a href="mailto:dri-devel@lists.freedesktop.org" data-auth="NotApplicable" class="x_x_moz-txt-link-rfc2396E" moz-do-not-send="true">
<dri-devel@lists.freedesktop.org></a>; <a href="mailto:amd-gfx@lists.freedesktop.org" data-auth="NotApplicable" class="x_x_moz-txt-link-abbreviated
x_moz-txt-link-freetext moz-txt-link-freetext" moz-do-not-send="true">
amd-gfx@lists.freedesktop.org</a> <a href="mailto:amd-gfx@lists.freedesktop.org" data-auth="NotApplicable" class="x_x_moz-txt-link-rfc2396E" moz-do-not-send="true">
<amd-gfx@lists.freedesktop.org></a><br>
<b>Subject:</b> Re: [PATCH] drm/ttm: fix ttm tt
init fail when size exceeds kmalloc limit</font>
<div> </div>
</div>
<div>Am 20.04.22 um 11:07 schrieb Wang, Yang(Kevin):<br>
<blockquote type="cite">
<p style="margin-top: 0px; margin-bottom:
0px;margin-top:0px; margin-bottom:0px;
margin-top:0px; margin-bottom:0px;
font-family:Arial; font-size:10pt;
color:#0000FF; margin:5pt" align="Left">
[AMD Official Use Only]<br>
</p>
<br>
<div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif;
font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<hr tabindex="-1" style="display:inline-block;
width:98%">
<div id="x_x_x_divRplyFwdMsg" dir="ltr"><font style="font-size:11pt" face="Calibri,
sans-serif" color="#000000"><b>From:</b>
Koenig, Christian
<a href="mailto:Christian.Koenig@amd.com" data-auth="NotApplicable" class="x_x_x_moz-txt-link-rfc2396E" moz-do-not-send="true">
<Christian.Koenig@amd.com></a><br>
<b>Sent:</b> Wednesday, April 20, 2022
5:00 PM<br>
<b>To:</b> Wang, Yang(Kevin) <a href="mailto:KevinYang.Wang@amd.com" data-auth="NotApplicable" class="x_x_x_moz-txt-link-rfc2396E" moz-do-not-send="true">
<KevinYang.Wang@amd.com></a>; <a href="mailto:dri-devel@lists.freedesktop.org" data-auth="NotApplicable" class="x_x_x_moz-txt-link-abbreviated
x_x_moz-txt-link-freetext
x_moz-txt-link-freetext
moz-txt-link-freetext" moz-do-not-send="true">
dri-devel@lists.freedesktop.org</a> <a href="mailto:dri-devel@lists.freedesktop.org" data-auth="NotApplicable" class="x_x_x_moz-txt-link-rfc2396E" moz-do-not-send="true">
<dri-devel@lists.freedesktop.org></a>;
<a href="mailto:amd-gfx@lists.freedesktop.org" data-auth="NotApplicable" class="x_x_x_moz-txt-link-abbreviated
x_x_moz-txt-link-freetext
x_moz-txt-link-freetext
moz-txt-link-freetext" moz-do-not-send="true">
amd-gfx@lists.freedesktop.org</a> <a href="mailto:amd-gfx@lists.freedesktop.org" data-auth="NotApplicable" class="x_x_x_moz-txt-link-rfc2396E" moz-do-not-send="true">
<amd-gfx@lists.freedesktop.org></a><br>
<b>Subject:</b> Re: [PATCH] drm/ttm: fix
ttm tt init fail when size exceeds kmalloc
limit</font>
<div> </div>
</div>
<div class="x_x_x_BodyFragment"><font size="2"><span style="font-size:11pt">
<div class="x_x_x_PlainText
x_x_x_elementToProof">Am 20.04.22 um
10:56 schrieb Yang Wang:<br>
> if the __GFP_ZERO is set, the
kvmalloc() can't fallback to use
vmalloc()<br>
<br>
Hui what? Why should kvmalloc() not be
able to fallback to vmalloc() <br>
when __GFP_ZERO is set?<br>
<br>
And even that is really the case then
that sounds like a bug in kvmalloc().</div>
<div class="x_x_x_PlainText
x_x_x_elementToProof"><br>
Regards,<br>
Christian.</div>
<div class="x_x_x_PlainText
x_x_x_elementToProof"><br>
<div class="x_x_x_PlainText" style="margin:0px;
background-color:rgb(255,255,255)">
[kevin]:</div>
</div>
<div class="x_x_x_PlainText
x_x_x_elementToProof"><span class="x_x_x_PlainText" style="margin:0px;
background-color:rgb(255,255,255)">it
is really test case from libdrm
amdgpu test, which try to allocate a
big BO which will cause ttm tt init
fail.</span><br>
</div>
</span></font></div>
</div>
</blockquote>
<br>
<br>
LOL! Guys, this test case is intended to fail!<br>
<b><br>
</b>The test consists of allocating a buffer so
ridiculous large that it should never succeed and
be rejected by the kernel driver.<br>
<br>
This patch here is a really clear NAK.<br>
<br>
Regards,<br>
Christian.<br>
<br>
<blockquote type="cite">
<div>
<div class="x_x_x_BodyFragment"><font size="2"><span style="font-size:11pt">
<div class="x_x_x_PlainText
x_x_x_elementToProof"><span class="x_x_x_PlainText" style="margin:0px;
background-color:rgb(255,255,255)">it
may be a kvmalloc() bug, and this
patch can as a workaround in<span style="background-color:rgb(255,255,255);
display:inline!important"> ttm</span> before
this issue fix.</span></div>
<div class="x_x_x_PlainText
x_x_x_elementToProof"><span class="x_x_x_PlainText" style="margin:0px;
background-color:rgb(255,255,255)"><br>
</span></div>
<div class="x_x_x_PlainText
x_x_x_elementToProof"><span class="x_x_x_PlainText" style="margin:0px;
background-color:rgb(255,255,255)">void
*kvmalloc_node(size_t size, gfp_t
flags, int node) <br>
</span></div>
<div class="x_x_x_PlainText
x_x_x_elementToProof"><span class="x_x_x_PlainText" style="margin:0px;
background-color:rgb(255,255,255)">{</span></div>
<div class="x_x_x_PlainText
x_x_x_elementToProof"><span class="x_x_x_PlainText" style="margin:0px;
background-color:rgb(255,255,255)">...</span></div>
<div class="x_x_x_PlainText
x_x_x_elementToProof"><span class="x_x_x_PlainText" style="margin:0px;
background-color:rgb(255,255,255)">
if ((flags & GFP_KERNEL)
!= GFP_KERNEL)<br>
</span></div>
<div class="x_x_x_PlainText
x_x_x_elementToProof"><span class="x_x_x_PlainText" style="margin:0px;
background-color:rgb(255,255,255)">
return
kmalloc_node(size, flags, node);<br>
</span></div>
<div class="x_x_x_PlainText
x_x_x_elementToProof"><span class="x_x_x_PlainText" style="margin:0px;
background-color:rgb(255,255,255)">...</span></div>
<div class="x_x_x_PlainText
x_x_x_elementToProof"><span class="x_x_x_PlainText" style="margin:0px;
background-color:rgb(255,255,255)">}</span></div>
<div class="x_x_x_PlainText
x_x_x_elementToProof"><br>
</div>
<div class="x_x_x_PlainText
x_x_x_elementToProof">Best Regards,</div>
<div class="x_x_x_PlainText
x_x_x_elementToProof">Kevin<br>
<br>
> to allocate memory, when request
size is exceeds kmalloc limit, it will<br>
> cause allocate memory fail.<br>
><br>
> e.g: when ttm want to create a BO
with 1TB size, it maybe fail.<br>
><br>
> Signed-off-by: Yang Wang <a href="mailto:KevinYang.Wang@amd.com" data-auth="NotApplicable" class="x_x_x_moz-txt-link-rfc2396E" moz-do-not-send="true">
<KevinYang.Wang@amd.com></a><br>
> ---<br>
> drivers/gpu/drm/ttm/ttm_tt.c |
14 +++++++++++---<br>
> 1 file changed, 11
insertions(+), 3 deletions(-)<br>
><br>
> diff --git
a/drivers/gpu/drm/ttm/ttm_tt.c
b/drivers/gpu/drm/ttm/ttm_tt.c<br>
> index 79c870a3bef8..9f2f3e576b8d
100644<br>
> ---
a/drivers/gpu/drm/ttm/ttm_tt.c<br>
> +++
b/drivers/gpu/drm/ttm/ttm_tt.c<br>
> @@ -97,9 +97,12 @@ int
ttm_tt_create(struct ttm_buffer_object
*bo, bool zero_alloc)<br>
> static int
ttm_tt_alloc_page_directory(struct
ttm_tt *ttm)<br>
> {<br>
> ttm->pages =
kvmalloc_array(ttm->num_pages,
sizeof(void*),<br>
> - GFP_KERNEL
| __GFP_ZERO);<br>
> +
GFP_KERNEL);<br>
> if (!ttm->pages)<br>
> return -ENOMEM;<br>
> +<br>
> + memset(ttm->pages, 0,
ttm->num_pages * sizeof(void *));<br>
> +<br>
> return 0;<br>
> }<br>
> <br>
> @@ -108,10 +111,12 @@ static int
ttm_dma_tt_alloc_page_directory(struct
ttm_tt *ttm)<br>
> ttm->pages =
kvmalloc_array(ttm->num_pages,<br>
> sizeof(*ttm->pages) +<br>
> sizeof(*ttm->dma_address),<br>
> -
GFP_KERNEL | __GFP_ZERO);<br>
> +
GFP_KERNEL);<br>
> if (!ttm->pages)<br>
> return -ENOMEM;<br>
> <br>
> + memset(ttm->pages, 0,
ttm->num_pages *
(sizeof(*ttm->pages) +
sizeof(*ttm->dma_address)));<br>
> +<br>
> ttm->dma_address =
(void *)(ttm->pages +
ttm->num_pages);<br>
> return 0;<br>
> }<br>
> @@ -120,9 +125,12 @@ static int
ttm_sg_tt_alloc_page_directory(struct
ttm_tt *ttm)<br>
> {<br>
> ttm->dma_address =
kvmalloc_array(ttm->num_pages,<br>
>
sizeof(*ttm->dma_address),<br>
>
-
GFP_KERNEL | __GFP_ZERO);<br>
>
+
GFP_KERNEL);<br>
> if (!ttm->dma_address)<br>
> return -ENOMEM;<br>
> +<br>
> + memset(ttm->dma_address,
0, ttm->num_pages *
sizeof(*ttm->dma_address));<br>
> +<br>
> return 0;<br>
> }<br>
> <br>
<br>
</div>
</span></font></div>
</div>
</blockquote>
<br>
</div>
</div>
</blockquote>
<br>
</div>
</div>
</blockquote>
<br>
</div>
</div>
</blockquote>
<br>
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