<!DOCTYPE html><html><head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> </head> <body> <p><br> </p> <div class="moz-cite-prefix">On 1/6/2025 8:02 PM, Deng, Emily wrote:<br> </div> <blockquote type="cite" cite="mid:PH0PR12MB5417A0CED996D52E33D234B98F112@PH0PR12MB5417.namprd12.prod.outlook.com"> <meta name="Generator" content="Microsoft Word 15 (filtered medium)"> <style>@font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4;}@font-face {font-family:DengXian; panose-1:2 1 6 0 3 1 1 1 1 1;}@font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4;}@font-face {font-family:Aptos;}@font-face {font-family:"\@DengXian"; panose-1:2 1 6 0 3 1 1 1 1 1;}@font-face {font-family:Consolas; panose-1:2 11 6 9 2 2 4 3 2 4;}p.MsoNormal, li.MsoNormal, div.MsoNormal {margin:0in; font-size:12.0pt; font-family:"Aptos",sans-serif;}a:link, span.MsoHyperlink {mso-style-priority:99; color:blue; text-decoration:underline;}pre {mso-style-priority:99; mso-style-link:"HTML Preformatted Char"; margin:0in; font-size:10.0pt; font-family:"Courier New";}span.HTMLPreformattedChar {mso-style-name:"HTML Preformatted Char"; mso-style-priority:99; mso-style-link:"HTML Preformatted"; font-family:Consolas;}span.EmailStyle21 {mso-style-type:personal-reply; font-family:"Arial",sans-serif; color:windowtext;}.MsoChpDefault {mso-style-type:export-only; font-size:10.0pt; mso-ligatures:none;}div.WordSection1 {page:WordSection1;}</style> <p style="font-family:Calibri;font-size:10pt;color:#0000FF;margin:5pt;font-style:normal;font-weight:normal;text-decoration:none;" align="Left"> [AMD Official Use Only - AMD Internal Distribution Only]<br> </p> <br> <div> <div class="WordSection1"> <p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Arial",sans-serif"><o:p> </o:p></span></p> <p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Arial",sans-serif"><o:p> </o:p></span></p> <div style="border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt"> <div> <div style="border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in"> <p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> Chen, Xiaogang <a class="moz-txt-link-rfc2396E" href="mailto:Xiaogang.Chen@amd.com"><Xiaogang.Chen@amd.com></a> <br> <b>Sent:</b> Monday, January 6, 2025 11:27 PM<br> <b>To:</b> Deng, Emily <a class="moz-txt-link-rfc2396E" href="mailto:Emily.Deng@amd.com"><Emily.Deng@amd.com></a>; <a class="moz-txt-link-abbreviated" href="mailto:amd-gfx@lists.freedesktop.org">amd-gfx@lists.freedesktop.org</a><br> <b>Subject:</b> Re: [PATCH] drm/amdkfd: Fix partial migrate issue<o:p></o:p></span></p> </div> </div> <p class="MsoNormal"><o:p> </o:p></p> <p><o:p> </o:p></p> <div> <p class="MsoNormal">On 1/2/2025 6:06 PM, Emily Deng wrote:<o:p></o:p></p> </div> <blockquote style="margin-top:5.0pt;margin-bottom:5.0pt"> <pre>For partial migrate from ram to vram, the migrate->cpages is not<o:p></o:p></pre> <pre>equal to migrate->npages, should use migrate->npages to check all needed<o:p></o:p></pre> <pre>migrate pages which could be copied or not.<o:p></o:p></pre> <pre><o:p> </o:p></pre> <pre>And only need to set those pages could be migrated to migrate->dst[i], or<o:p></o:p></pre> <pre>the migrate_vma_pages will migrate the wrong pages based on the migrate->dst[i].<o:p></o:p></pre> <pre><o:p> </o:p></pre> <pre>Signed-off-by: Emily Deng <a href="mailto:Emily.Deng@amd.com" moz-do-not-send="true"><Emily.Deng@amd.com></a><o:p></o:p></pre> <pre>---<o:p></o:p></pre> <pre> drivers/gpu/drm/amd/amdkfd/kfd_migrate.c | 8 ++++----<o:p></o:p></pre> <pre> 1 file changed, 4 insertions(+), 4 deletions(-)<o:p></o:p></pre> <pre><o:p> </o:p></pre> <pre>diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c<o:p></o:p></pre> <pre>index 4b275937d05e..5c96c2d425e3 100644<o:p></o:p></pre> <pre>--- a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c<o:p></o:p></pre> <pre>+++ b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c<o:p></o:p></pre> <pre>@@ -278,7 +278,7 @@ svm_migrate_copy_to_vram(struct kfd_node *node, struct svm_range *prange,<o:p></o:p></pre> <pre> struct migrate_vma *migrate, struct dma_fence **mfence,<o:p></o:p></pre> <pre> dma_addr_t *scratch, uint64_t ttm_res_offset)<o:p></o:p></pre> <pre> {<o:p></o:p></pre> <pre>- uint64_t npages = migrate->cpages;<o:p></o:p></pre> <pre>+ uint64_t npages = migrate->npages;<o:p></o:p></pre> </blockquote> <p class="MsoNormal">I agree this part.<br> <br> <o:p></o:p></p> <blockquote style="margin-top:5.0pt;margin-bottom:5.0pt"> <pre><o:p> </o:p></pre> <pre> struct amdgpu_device *adev = node->adev;<o:p></o:p></pre> <pre> struct device *dev = adev->dev;<o:p></o:p></pre> <pre> struct amdgpu_res_cursor cursor;<o:p></o:p></pre> <pre>@@ -299,9 +299,6 @@ svm_migrate_copy_to_vram(struct kfd_node *node, struct svm_range *prange,<o:p></o:p></pre> <pre> struct page *spage;<o:p></o:p></pre> <pre> <o:p></o:p></pre> <pre> dst[i] = cursor.start + (j << PAGE_SHIFT);<o:p></o:p></pre> <pre>- migrate->dst[i] = svm_migrate_addr_to_pfn(adev, dst[i]);<o:p></o:p></pre> <pre>- svm_migrate_get_vram_page(prange, migrate->dst[i]);<o:p></o:p></pre> <pre>- migrate->dst[i] = migrate_pfn(migrate->dst[i]);<o:p></o:p></pre> <pre> <o:p></o:p></pre> <pre> spage = migrate_pfn_to_page(migrate->src[i]);<o:p></o:p></pre> <pre> if (spage && !is_zone_device_page(spage)) {<o:p></o:p></pre> <pre>@@ -345,6 +342,9 @@ svm_migrate_copy_to_vram(struct kfd_node *node, struct svm_range *prange,<o:p></o:p></pre> <pre> } else {<o:p></o:p></pre> <pre> j++;<o:p></o:p></pre> <pre> }<o:p></o:p></pre> <pre>+ migrate->dst[i] = svm_migrate_addr_to_pfn(adev, dst[i]);<o:p></o:p></pre> <pre>+ svm_migrate_get_vram_page(prange, migrate->dst[i]);<o:p></o:p></pre> <pre>+ migrate->dst[i] = migrate_pfn(migrate->dst[i]);<o:p></o:p></pre> </blockquote> <p>I think what current code misses here is that migrate->dst[i] should match migrate->src[i]: migrate->dst[i](vram page) got set for page that will be migrated from system ram, otherwise migrate->dst[i] should be zero. Your change makes migrates->dst[i] not set though its page has been migrated by svm_migrate_copy_memory_gart for the case that cpages != npages, because you set migrate->dst[i] at end of loop and use 'continue' after migration.<o:p></o:p></p> <p>The page migration happens at svm_migrate_copy_memory_gart, not migrate_vma_pages that migrates struct page meta-data from source struct page to destination struct page and has mmu notification.<o:p></o:p></p> <p>Regards<o:p></o:p></p> <p>Xiaogang<o:p></o:p></p> <p><span style="font-size:11.0pt;font-family:"Arial",sans-serif">The </span>migrate->dst[i] default value is 0. The purpose of the change is to match the migrate->dst[i] and migrate->src[i]. And for svm_migrate_copy_to_vram, it only will call svm_migrate_copy_memory_gart to copy those pages which need to be migrated, for those don’t need migrate pages, it won’t call svm_migrate_copy_memory_gart.</p> </div> </div> </div> </blockquote> <p>Yes, the issue here is we need match migrate->dst[i] and migrate->src[i]: migrate->dst[i] need be set only when its correspondent migrate->src[i] page will be migrated or the src page has dma address setup by dma_map_page. Then why not set migrate->dst[i] at same time when have dma_map_page for src page? That way will simplify the logic and not need use amdgpu_res_next to jump vram cursor. <br> </p> <p>Regards</p> <p>Xiaogang<br> </p> <blockquote type="cite" cite="mid:PH0PR12MB5417A0CED996D52E33D234B98F112@PH0PR12MB5417.namprd12.prod.outlook.com"> <div> <div class="WordSection1"> <div style="border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt"> <p><o:p></o:p></p> <blockquote style="margin-top:5.0pt;margin-bottom:5.0pt"> <pre><o:p> </o:p></pre> <pre> }<o:p></o:p></pre> <pre> <o:p></o:p></pre> <pre> r = svm_migrate_copy_memory_gart(adev, src + i - j, dst + i - j, j,<o:p></o:p></pre> </blockquote> </div> </div> </div> </blockquote> </body> </html>