On 14.07.25 07:18, Dave Airlie wrote: > From: Dave Airlie <airl...@redhat.com> > > There is an existing workload that cgroup support might regress, > the systems are setup to allocate 1GB of uncached pages at system > startup to prime the pool, then any further users will take them > from the pool. The current cgroup code might handle that, but > it also may regress, so add an option to ttm to avoid using > memcg for the pool pages. > > Signed-off-by: Dave Airlie <airl...@redhat.com> > --- > drivers/gpu/drm/ttm/ttm_pool.c | 19 +++++++++++++++++-- > 1 file changed, 17 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/ttm/ttm_pool.c b/drivers/gpu/drm/ttm/ttm_pool.c > index 1e6da2cc1f06..9d84d9991176 100644 > --- a/drivers/gpu/drm/ttm/ttm_pool.c > +++ b/drivers/gpu/drm/ttm/ttm_pool.c > @@ -118,6 +118,21 @@ static unsigned long page_pool_size; > MODULE_PARM_DESC(page_pool_size, "Number of pages in the WC/UC/DMA pool per > NUMA node"); > module_param(page_pool_size, ulong, 0644);
I think we need that for the whole memcg integration and off by default for now. Regards, Christian. > > +/* > + * Don't use the memcg aware lru for pooled pages. > + * > + * There are use-cases where for example one application in a cgroup will > preallocate 1GB > + * of uncached pages, and immediately release them into the pool, for other > consumers > + * to use. This use-case could be handled with a proper cgroup hierarchy, > but to allow > + * that use case to continue to operate as-is, add a module option. > + * > + * This still stores the pages in the list_lru, it just doesn't use the > memcg when > + * adding/removing them. > + */ > +static bool pool_cgroup = true; > +MODULE_PARM_DESC(pool_cgroup, "Manage pooled memory using cgroups (default: > true)"); > +module_param(pool_cgroup, bool, 0444); > + > static unsigned long pool_node_limit[MAX_NUMNODES]; > static atomic_long_t allocated_pages[MAX_NUMNODES]; > > @@ -305,7 +320,7 @@ static void ttm_pool_type_give(struct ttm_pool_type *pt, > struct page *p) > > INIT_LIST_HEAD(&p->lru); > rcu_read_lock(); > - list_lru_add(&pt->pages, &p->lru, nid, page_memcg_check(p)); > + list_lru_add(&pt->pages, &p->lru, nid, pool_cgroup ? > page_memcg_check(p) : NULL); > rcu_read_unlock(); > > atomic_long_add(num_pages, &allocated_pages[nid]); > @@ -354,7 +369,7 @@ static struct page *ttm_pool_type_take(struct > ttm_pool_type *pt, int nid, > struct page *page_out = NULL; > int ret; > struct mem_cgroup *orig_memcg = orig_objcg ? > get_mem_cgroup_from_objcg(orig_objcg) : NULL; > - struct mem_cgroup *memcg = orig_memcg; > + struct mem_cgroup *memcg = pool_cgroup ? orig_memcg : NULL; > > /* > * Attempt to get a page from the current memcg, but if it hasn't got > any in it's level,
