Add a function to pin, and to unipn memory and adjust the calculations in dmem_cgroup_state_evict_valuable().
Signed-off-by: Maarten Lankhorst <[email protected]> --- include/linux/cgroup_dmem.h | 2 ++ kernel/cgroup/dmem.c | 57 +++++++++++++++++++++++++++++++++++-- 2 files changed, 56 insertions(+), 3 deletions(-) diff --git a/include/linux/cgroup_dmem.h b/include/linux/cgroup_dmem.h index dd4869f1d736e..a981bb692ba22 100644 --- a/include/linux/cgroup_dmem.h +++ b/include/linux/cgroup_dmem.h @@ -21,6 +21,8 @@ int dmem_cgroup_try_charge(struct dmem_cgroup_region *region, u64 size, struct dmem_cgroup_pool_state **ret_pool, struct dmem_cgroup_pool_state **ret_limit_pool); void dmem_cgroup_uncharge(struct dmem_cgroup_pool_state *pool, u64 size); +int dmem_cgroup_try_pin(struct dmem_cgroup_pool_state *pool, u64 size); +void dmem_cgroup_unpin(struct dmem_cgroup_pool_state *pool, u64 size); bool dmem_cgroup_state_evict_valuable(struct dmem_cgroup_pool_state *limit_pool, struct dmem_cgroup_pool_state *test_pool, bool ignore_low, bool *ret_hit_low); diff --git a/kernel/cgroup/dmem.c b/kernel/cgroup/dmem.c index 10b63433f0573..ec8b1ffec78de 100644 --- a/kernel/cgroup/dmem.c +++ b/kernel/cgroup/dmem.c @@ -147,6 +147,11 @@ static u64 get_resource_current(struct dmem_cgroup_pool_state *pool) return pool ? page_counter_read(&pool->cnt) : 0; } +static u64 get_resource_pinned(struct dmem_cgroup_pool_state *pool) +{ + return pool ? page_counter_pinned(&pool->cnt) : 0; +} + static void reset_all_resource_limits(struct dmem_cgroup_pool_state *rpool) { set_resource_min(rpool, 0); @@ -270,7 +275,7 @@ bool dmem_cgroup_state_evict_valuable(struct dmem_cgroup_pool_state *limit_pool, { struct dmem_cgroup_pool_state *pool = test_pool; struct page_counter *ctest; - u64 used, min, low; + u64 used, min, low, pinned; /* Can always evict from current pool, despite limits */ if (limit_pool == test_pool) @@ -296,16 +301,18 @@ bool dmem_cgroup_state_evict_valuable(struct dmem_cgroup_pool_state *limit_pool, ctest = &test_pool->cnt; + /* Protection is calculated without pinned memory */ dmem_cgroup_calculate_protection(limit_pool, test_pool); used = page_counter_read(ctest); - min = READ_ONCE(ctest->emin); + pinned = page_counter_pinned(ctest); + min = READ_ONCE(ctest->emin) + pinned; if (used <= min) return false; if (!ignore_low) { - low = READ_ONCE(ctest->elow); + low = READ_ONCE(ctest->elow) + pinned; if (used > low) return true; @@ -641,6 +648,41 @@ int dmem_cgroup_try_charge(struct dmem_cgroup_region *region, u64 size, } EXPORT_SYMBOL_GPL(dmem_cgroup_try_charge); +/** + * dmem_cgroup_unpin() - Unpin from a pool. + * @pool: Pool to unpin. + * @size: Size to unpin. + * + * Undoes the effects of dmem_cgroup_try_pin. + * Must be called with the returned pool as argument, + * and same @index and @size. + */ +void dmem_cgroup_unpin(struct dmem_cgroup_pool_state *pool, u64 size) +{ + if (pool) + page_counter_unpin(&pool->cnt, size); +} +EXPORT_SYMBOL_GPL(dmem_cgroup_unpin); + +/** + * dmem_cgroup_try_pin() - Try pinning an existing allocation to a region. + * @pool: dmem region to pin + * @size: Size (in bytes) to pin. + * + * This function pins in @pool for a size of @size bytes. + * + * If the function succeeds, the memory is succesfully accounted as being pinned. + * The memory may not be uncharged before unpin is called. + * + * Return: 0 on success, -EAGAIN on hitting a limit, or a negative errno on failure. + */ +int dmem_cgroup_try_pin(struct dmem_cgroup_pool_state *pool, u64 size) +{ + return page_counter_try_pin(&pool->cnt, size) ? 0 : -EAGAIN; + +} +EXPORT_SYMBOL_GPL(dmem_cgroup_try_pin); + static int dmem_cgroup_region_capacity_show(struct seq_file *sf, void *v) { struct dmem_cgroup_region *region; @@ -756,6 +798,11 @@ static int dmem_cgroup_region_current_show(struct seq_file *sf, void *v) return dmemcg_limit_show(sf, v, get_resource_current); } +static int dmem_cgroup_region_pinned_show(struct seq_file *sf, void *v) +{ + return dmemcg_limit_show(sf, v, get_resource_pinned); +} + static int dmem_cgroup_region_min_show(struct seq_file *sf, void *v) { return dmemcg_limit_show(sf, v, get_resource_min); @@ -799,6 +846,10 @@ static struct cftype files[] = { .name = "current", .seq_show = dmem_cgroup_region_current_show, }, + { + .name = "pinned", + .seq_show = dmem_cgroup_region_pinned_show, + }, { .name = "min", .write = dmem_cgroup_region_min_write, -- 2.50.0
