<!DOCTYPE html><html><head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> </head> <body> Am 16.02.24 um 15:20 schrieb Thomas Hellström: [SNIP] <blockquote type="cite" cite="mid:47fc8e42dcfd868341ffc32754c302e58ac49484.camel@linux.intel.com"> <blockquote type="cite"> <pre class="moz-quote-pre" wrap="">My approach was basically to not only lock the current BO, but also the next one. Since only a locked BO can move on the LRU we effectively created an anchor. Before I dig into the code a couple of questions: </pre> </blockquote> <pre class="moz-quote-pre" wrap="">These are described in the patches but brief comments inline. </pre> <blockquote type="cite"> <pre class="moz-quote-pre" wrap="">1. How do you distinct BOs and iteration anchors on the LRU? </pre> </blockquote> <pre class="moz-quote-pre" wrap="">Using a struct ttm_lru_item, containing a struct list_head and the type. List nodes embeds this instead of a struct list_head. This is larger than the list head but makes it explicit what we're doing.</pre> </blockquote> Need to look deeper into the code of this, but it would be nice if we could abstract that better somehow. <blockquote type="cite" cite="mid:47fc8e42dcfd868341ffc32754c302e58ac49484.camel@linux.intel.com"> <blockquote type="cite"> <pre class="moz-quote-pre" wrap="">2. How do you detect that a bulk list moved on the LRU? </pre> </blockquote> <pre class="moz-quote-pre" wrap="">An age u64 counter on the bulk move that we're comparing against. It's updated each time it moves. </pre> <blockquote type="cite"> <pre class="moz-quote-pre" wrap="">3. How do you remove the iteration anchors from the bulk list? </pre> </blockquote> <pre class="moz-quote-pre" wrap="">A function call at the end of iteration, that the function iterating is requried to call.</pre> </blockquote> Thinking quite a bit about that in the last week and I came to the conclusion that this might be overkill. All BOs in a bulk share the same reservation object. So when you acquired one you can just keep the dma-resv locked even after evicting the BO. Since moving BOs requires locking the dma-resv object the whole problem then just boils down to a list_for_each_element_safe(). That's probably a bit simpler than doing the add/remove dance. Regards, Christian. <blockquote type="cite" cite="mid:47fc8e42dcfd868341ffc32754c302e58ac49484.camel@linux.intel.com"> <pre class="moz-quote-pre" wrap=""> /Thomas </pre> <blockquote type="cite"> <pre class="moz-quote-pre" wrap=""> Regards, Christian. </pre> <blockquote type="cite"> <pre class="moz-quote-pre" wrap=""> The restartable property is used in patch 4 to restart swapout if needed, but the main purpose is this paves the way for shrinker- and exhaustive eviction. Cc: Christian König <a class="moz-txt-link-rfc2396E" href="mailto:christian.koenig@amd.com"><christian.koenig@amd.com></a> Cc: <a class="moz-txt-link-rfc2396E" href="mailto:dri-devel@lists.freedesktop.org"><dri-devel@lists.freedesktop.org></a> Thomas Hellström (4): drm/ttm: Allow TTM LRU list nodes of different types drm/ttm: Use LRU hitches drm/ttm: Consider hitch moves within bulk sublist moves drm/ttm: Allow continued swapout after -ENOSPC falure drivers/gpu/drm/ttm/ttm_bo.c | 1 + drivers/gpu/drm/ttm/ttm_device.c | 33 +++-- drivers/gpu/drm/ttm/ttm_resource.c | 202 +++++++++++++++++++++++- ----- include/drm/ttm/ttm_resource.h | 91 +++++++++++-- 4 files changed, 267 insertions(+), 60 deletions(-) </pre> </blockquote> <pre class="moz-quote-pre" wrap=""> </pre> </blockquote> <pre class="moz-quote-pre" wrap=""> </pre> </blockquote> </body> </html>