drm.lgpu A read-write nested-keyed file which exists on all cgroups. Each entry is keyed by the DRM device's major:minor.
lgpu stands for logical GPU, it is an abstraction used to subdivide a physical DRM device for the purpose of resource management. This file stores user configuration while the drm.lgpu.effective reflects the actual allocation after considering the relationship between the cgroups and their configurations.
The lgpu is a discrete quantity that is device specific (i.e. some DRM devices may have 64 lgpus while others may have 100 lgpus.) The lgpu is a single quantity that can be allocated in three different ways denoted by the following nested keys.
===== ============================================== weight Allocate by proportion in relationship with active sibling cgroups count Allocate by amount statically, treat lgpu as anonymous resources list Allocate statically, treat lgpu as named resource ===== ==============================================
For example: 226:0 weight=100 count=256 list=0-255 226:1 weight=100 count=4 list=0,2,4,6 226:2 weight=100 count=32 list=32-63 226:3 weight=100 count=0 list= 226:4 weight=500 count=0 list=
lgpu is represented by a bitmap and uses the bitmap_parselist kernel function so the list key input format is a comma-separated list of decimal numbers and ranges.
Consecutively set bits are shown as two hyphen-separated decimal numbers, the smallest and largest bit numbers set in the range. Optionally each range can be postfixed to denote that only parts of it should be set. The range will divided to groups of specific size. Syntax: range:used_size/group_size Example: 0-1023:2/256 ==> 0,1,256,257,512,513,768,769
The count key is the hamming weight / hweight of the bitmap.
Weight, count and list accept the max and default keywords.
Some DRM devices may only support lgpu as anonymous resources. In such case, the significance of the position of the set bits in list will be ignored.
The weight quantity is only in effect when static allocation is not used (by setting count=0) for this cgroup. The weight quantity distributes lgpus that are not statically allocated by the siblings. For example, given siblings cgroupA, cgroupB and cgroupC for a DRM device that has 64 lgpus, if cgroupA occupies 0-63, no lgpu is available to be distributed by weight. Similarly, if cgroupA has list=0-31 and cgroupB has list=16-63, cgroupC will be starved if it tries to allocate by weight.
On the other hand, if cgroupA has weight=100 count=0, cgroupB has list=16-47, and cgroupC has weight=100 count=0, then 32 lgpus are available to be distributed evenly between cgroupA and cgroupC. In drm.lgpu.effective, cgroupA will have list=0-15 and cgroupC will have list=48-63.
This lgpu resource supports the 'allocation' and 'weight' resource distribution model.
drm.lgpu.effective A read-only nested-keyed file which exists on all cgroups. Each entry is keyed by the DRM device's major:minor.
lgpu stands for logical GPU, it is an abstraction used to subdivide a physical DRM device for the purpose of resource management. This file reflects the actual allocation after considering the relationship between the cgroups and their configurations in drm.lgpu.
Change-Id: Idde0ef9a331fd67bb9c7eb8ef9978439e6452488 Signed-off-by: Kenny Ho Kenny.Ho@amd.com --- Documentation/admin-guide/cgroup-v2.rst | 80 ++++++ include/drm/drm_cgroup.h | 3 + include/linux/cgroup_drm.h | 22 ++ kernel/cgroup/drm.c | 324 +++++++++++++++++++++++- 4 files changed, 427 insertions(+), 2 deletions(-)
diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index ce5dc027366a..d8a41956e5c7 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -2120,6 +2120,86 @@ DRM Interface Files Set largest allocation for /dev/dri/card1 to 4MB echo "226:1 4m" > drm.buffer.peak.max
+ drm.lgpu + A read-write nested-keyed file which exists on all cgroups. + Each entry is keyed by the DRM device's major:minor. + + lgpu stands for logical GPU, it is an abstraction used to + subdivide a physical DRM device for the purpose of resource + management. This file stores user configuration while the + drm.lgpu.effective reflects the actual allocation after + considering the relationship between the cgroups and their + configurations. + + The lgpu is a discrete quantity that is device specific (i.e. + some DRM devices may have 64 lgpus while others may have 100 + lgpus.) The lgpu is a single quantity that can be allocated + in three different ways denoted by the following nested keys. + + ===== ============================================== + weight Allocate by proportion in relationship with + active sibling cgroups + count Allocate by amount statically, treat lgpu as + anonymous resources + list Allocate statically, treat lgpu as named + resource + ===== ============================================== + + For example: + 226:0 weight=100 count=256 list=0-255 + 226:1 weight=100 count=4 list=0,2,4,6 + 226:2 weight=100 count=32 list=32-63 + 226:3 weight=100 count=0 list= + 226:4 weight=500 count=0 list= + + lgpu is represented by a bitmap and uses the bitmap_parselist + kernel function so the list key input format is a + comma-separated list of decimal numbers and ranges. + + Consecutively set bits are shown as two hyphen-separated decimal + numbers, the smallest and largest bit numbers set in the range. + Optionally each range can be postfixed to denote that only parts + of it should be set. The range will divided to groups of + specific size. + Syntax: range:used_size/group_size + Example: 0-1023:2/256 ==> 0,1,256,257,512,513,768,769 + + The count key is the hamming weight / hweight of the bitmap. + + Weight, count and list accept the max and default keywords. + + Some DRM devices may only support lgpu as anonymous resources. + In such case, the significance of the position of the set bits + in list will be ignored. + + The weight quantity is only in effect when static allocation + is not used (by setting count=0) for this cgroup. The weight + quantity distributes lgpus that are not statically allocated by + the siblings. For example, given siblings cgroupA, cgroupB and + cgroupC for a DRM device that has 64 lgpus, if cgroupA occupies + 0-63, no lgpu is available to be distributed by weight. + Similarly, if cgroupA has list=0-31 and cgroupB has list=16-63, + cgroupC will be starved if it tries to allocate by weight. + + On the other hand, if cgroupA has weight=100 count=0, cgroupB + has list=16-47, and cgroupC has weight=100 count=0, then 32 + lgpus are available to be distributed evenly between cgroupA + and cgroupC. In drm.lgpu.effective, cgroupA will have + list=0-15 and cgroupC will have list=48-63. + + This lgpu resource supports the 'allocation' and 'weight' + resource distribution model. + + drm.lgpu.effective + A read-only nested-keyed file which exists on all cgroups. + Each entry is keyed by the DRM device's major:minor. + + lgpu stands for logical GPU, it is an abstraction used to + subdivide a physical DRM device for the purpose of resource + management. This file reflects the actual allocation after + considering the relationship between the cgroups and their + configurations in drm.lgpu. + GEM Buffer Ownership ~~~~~~~~~~~~~~~~~~~~
diff --git a/include/drm/drm_cgroup.h b/include/drm/drm_cgroup.h index 2b41d4d22e33..619a110cc748 100644 --- a/include/drm/drm_cgroup.h +++ b/include/drm/drm_cgroup.h @@ -17,6 +17,9 @@ struct drmcg_props {
s64 bo_limits_total_allocated_default; s64 bo_limits_peak_allocated_default; + + int lgpu_capacity; + DECLARE_BITMAP(lgpu_slots, MAX_DRMCG_LGPU_CAPACITY); };
void drmcg_bind(struct drm_minor (*(*acq_dm)(unsigned int minor_id)), diff --git a/include/linux/cgroup_drm.h b/include/linux/cgroup_drm.h index eae400f3d9b4..bb09704e7f71 100644 --- a/include/linux/cgroup_drm.h +++ b/include/linux/cgroup_drm.h @@ -11,10 +11,14 @@ /* limit defined per the way drm_minor_alloc operates */ #define MAX_DRM_DEV (64 * DRM_MINOR_RENDER)
+#define MAX_DRMCG_LGPU_CAPACITY 256 + enum drmcg_res_type { DRMCG_TYPE_BO_TOTAL, DRMCG_TYPE_BO_PEAK, DRMCG_TYPE_BO_COUNT, + DRMCG_TYPE_LGPU, + DRMCG_TYPE_LGPU_EFF, __DRMCG_TYPE_LAST, };
@@ -32,6 +36,24 @@ struct drmcg_device_resource { s64 bo_limits_peak_allocated;
s64 bo_stats_count_allocated; + + /** + * Logical GPU + * + * *_cfg are properties configured by users + * *_eff are the effective properties being applied to the hardware + * *_stg is used to calculate _eff before applying to _eff + * after considering the entire hierarchy + */ + DECLARE_BITMAP(lgpu_stg, MAX_DRMCG_LGPU_CAPACITY); + /* user configurations */ + s64 lgpu_weight_cfg; + DECLARE_BITMAP(lgpu_cfg, MAX_DRMCG_LGPU_CAPACITY); + /* effective lgpu for the cgroup after considering + * relationship with other cgroup + */ + s64 lgpu_count_eff; + DECLARE_BITMAP(lgpu_eff, MAX_DRMCG_LGPU_CAPACITY); };
/** diff --git a/kernel/cgroup/drm.c b/kernel/cgroup/drm.c index 5fcbbc13fa1c..a4e88a3704bb 100644 --- a/kernel/cgroup/drm.c +++ b/kernel/cgroup/drm.c @@ -9,6 +9,7 @@ #include <linux/seq_file.h> #include <linux/mutex.h> #include <linux/kernel.h> +#include <linux/bitmap.h> #include <linux/cgroup_drm.h> #include <drm/drm_file.h> #include <drm/drm_drv.h> @@ -41,6 +42,10 @@ enum drmcg_file_type { DRMCG_FTYPE_DEFAULT, };
+#define LGPU_LIMITS_NAME_LIST "list" +#define LGPU_LIMITS_NAME_COUNT "count" +#define LGPU_LIMITS_NAME_WEIGHT "weight" + /** * drmcg_bind - Bind DRM subsystem to cgroup subsystem * @acq_dm: function pointer to the drm_minor_acquire function @@ -98,6 +103,13 @@ static inline int init_drmcg_single(struct drmcg *drmcg, struct drm_device *dev) ddr->bo_limits_peak_allocated = dev->drmcg_props.bo_limits_peak_allocated_default;
+ bitmap_copy(ddr->lgpu_cfg, dev->drmcg_props.lgpu_slots, + MAX_DRMCG_LGPU_CAPACITY); + bitmap_copy(ddr->lgpu_stg, dev->drmcg_props.lgpu_slots, + MAX_DRMCG_LGPU_CAPACITY); + + ddr->lgpu_weight_cfg = CGROUP_WEIGHT_DFL; + return 0; }
@@ -121,6 +133,120 @@ static inline void drmcg_update_cg_tree(struct drm_device *dev) mutex_unlock(&cgroup_mutex); }
+static void drmcg_calculate_effective_lgpu(struct drm_device *dev, + const unsigned long *free_static, + const unsigned long *free_weighted, + struct drmcg *parent_drmcg) +{ + int capacity = dev->drmcg_props.lgpu_capacity; + DECLARE_BITMAP(lgpu_unused, MAX_DRMCG_LGPU_CAPACITY); + DECLARE_BITMAP(lgpu_by_weight, MAX_DRMCG_LGPU_CAPACITY); + struct drmcg_device_resource *parent_ddr; + struct drmcg_device_resource *ddr; + int minor = dev->primary->index; + struct cgroup_subsys_state *pos; + struct drmcg *child; + s64 weight_sum = 0; + s64 unused; + + parent_ddr = parent_drmcg->dev_resources[minor]; + + if (bitmap_empty(parent_ddr->lgpu_cfg, capacity)) + /* no static cfg, use weight for calculating the effective */ + bitmap_copy(parent_ddr->lgpu_stg, free_weighted, capacity); + else + /* lgpu statically configured, use the overlap as effective */ + bitmap_and(parent_ddr->lgpu_stg, free_static, + parent_ddr->lgpu_cfg, capacity); + + /* calculate lgpu available for distribution by weight for children */ + bitmap_copy(lgpu_unused, parent_ddr->lgpu_stg, capacity); + css_for_each_child(pos, &parent_drmcg->css) { + child = css_to_drmcg(pos); + ddr = child->dev_resources[minor]; + + if (bitmap_empty(ddr->lgpu_cfg, capacity)) + /* no static allocation, participate in weight dist */ + weight_sum += ddr->lgpu_weight_cfg; + else + /* take out statically allocated lgpu by siblings */ + bitmap_andnot(lgpu_unused, lgpu_unused, ddr->lgpu_cfg, + capacity); + } + + unused = bitmap_weight(lgpu_unused, capacity); + + css_for_each_child(pos, &parent_drmcg->css) { + child = css_to_drmcg(pos); + ddr = child->dev_resources[minor]; + + bitmap_zero(lgpu_by_weight, capacity); + /* no static allocation, participate in weight distribution */ + if (bitmap_empty(ddr->lgpu_cfg, capacity)) { + int c; + int p = 0; + + for (c = ddr->lgpu_weight_cfg * unused / weight_sum; + c > 0; c--) { + p = find_next_bit(lgpu_unused, capacity, p); + if (p < capacity) { + clear_bit(p, lgpu_unused); + set_bit(p, lgpu_by_weight); + } + } + + } + + drmcg_calculate_effective_lgpu(dev, parent_ddr->lgpu_stg, + lgpu_by_weight, child); + } +} + +static void drmcg_apply_effective_lgpu(struct drm_device *dev) +{ + int capacity = dev->drmcg_props.lgpu_capacity; + int minor = dev->primary->index; + struct drmcg_device_resource *ddr; + struct cgroup_subsys_state *pos; + struct drmcg *drmcg; + + if (root_drmcg == NULL) { + WARN_ON(root_drmcg == NULL); + return; + } + + rcu_read_lock(); + + /* process the entire cgroup tree from root to simplify the algorithm */ + drmcg_calculate_effective_lgpu(dev, dev->drmcg_props.lgpu_slots, + dev->drmcg_props.lgpu_slots, root_drmcg); + + /* apply changes to effective only if there is a change */ + css_for_each_descendant_pre(pos, &root_drmcg->css) { + drmcg = css_to_drmcg(pos); + ddr = drmcg->dev_resources[minor]; + + if (!bitmap_equal(ddr->lgpu_stg, ddr->lgpu_eff, capacity)) { + bitmap_copy(ddr->lgpu_eff, ddr->lgpu_stg, capacity); + ddr->lgpu_count_eff = + bitmap_weight(ddr->lgpu_eff, capacity); + } + } + rcu_read_unlock(); +} + +static void drmcg_apply_effective(enum drmcg_res_type type, + struct drm_device *dev, struct drmcg *changed_drmcg) +{ + switch (type) { + case DRMCG_TYPE_LGPU: + drmcg_apply_effective_lgpu(dev); + break; + default: + break; + } +} + /** * drmcg_register_dev - register a DRM device for usage in drm cgroup * @dev: DRM device @@ -143,7 +269,13 @@ void drmcg_register_dev(struct drm_device *dev) { dev->driver->drmcg_custom_init(dev, &dev->drmcg_props);
+ WARN_ON(dev->drmcg_props.lgpu_capacity != + bitmap_weight(dev->drmcg_props.lgpu_slots, + MAX_DRMCG_LGPU_CAPACITY)); + drmcg_update_cg_tree(dev); + + drmcg_apply_effective(DRMCG_TYPE_LGPU, dev, root_drmcg); } mutex_unlock(&drmcg_mutex); } @@ -297,7 +429,8 @@ static void drmcg_print_stats(struct drmcg_device_resource *ddr, }
static void drmcg_print_limits(struct drmcg_device_resource *ddr, - struct seq_file *sf, enum drmcg_res_type type) + struct seq_file *sf, enum drmcg_res_type type, + struct drm_device *dev) { if (ddr == NULL) { seq_puts(sf, "\n"); @@ -311,6 +444,25 @@ static void drmcg_print_limits(struct drmcg_device_resource *ddr, case DRMCG_TYPE_BO_PEAK: seq_printf(sf, "%lld\n", ddr->bo_limits_peak_allocated); break; + case DRMCG_TYPE_LGPU: + seq_printf(sf, "%s=%lld %s=%d %s=%*pbl\n", + LGPU_LIMITS_NAME_WEIGHT, + ddr->lgpu_weight_cfg, + LGPU_LIMITS_NAME_COUNT, + bitmap_weight(ddr->lgpu_cfg, + dev->drmcg_props.lgpu_capacity), + LGPU_LIMITS_NAME_LIST, + dev->drmcg_props.lgpu_capacity, + ddr->lgpu_cfg); + break; + case DRMCG_TYPE_LGPU_EFF: + seq_printf(sf, "%s=%lld %s=%*pbl\n", + LGPU_LIMITS_NAME_COUNT, + ddr->lgpu_count_eff, + LGPU_LIMITS_NAME_LIST, + dev->drmcg_props.lgpu_capacity, + ddr->lgpu_eff); + break; default: seq_puts(sf, "\n"); break; @@ -329,6 +481,17 @@ static void drmcg_print_default(struct drmcg_props *props, seq_printf(sf, "%lld\n", props->bo_limits_peak_allocated_default); break; + case DRMCG_TYPE_LGPU: + seq_printf(sf, "%s=%d %s=%d %s=%*pbl\n", + LGPU_LIMITS_NAME_WEIGHT, + CGROUP_WEIGHT_DFL, + LGPU_LIMITS_NAME_COUNT, + bitmap_weight(props->lgpu_slots, + props->lgpu_capacity), + LGPU_LIMITS_NAME_LIST, + props->lgpu_capacity, + props->lgpu_slots); + break; default: seq_puts(sf, "\n"); break; @@ -358,7 +521,7 @@ static int drmcg_seq_show_fn(int id, void *ptr, void *data) drmcg_print_stats(ddr, sf, type); break; case DRMCG_FTYPE_LIMIT: - drmcg_print_limits(ddr, sf, type); + drmcg_print_limits(ddr, sf, type, minor->dev); break; case DRMCG_FTYPE_DEFAULT: drmcg_print_default(&minor->dev->drmcg_props, sf, type); @@ -415,6 +578,115 @@ static int drmcg_process_limit_s64_val(char *sval, bool is_mem, return rc; }
+static void drmcg_nested_limit_parse(struct kernfs_open_file *of, + struct drm_device *dev, char *attrs) +{ + DECLARE_BITMAP(tmp_bitmap, MAX_DRMCG_LGPU_CAPACITY); + DECLARE_BITMAP(chk_bitmap, MAX_DRMCG_LGPU_CAPACITY); + enum drmcg_res_type type = + DRMCG_CTF_PRIV2RESTYPE(of_cft(of)->private); + struct drmcg *drmcg = css_to_drmcg(of_css(of)); + struct drmcg_props *props = &dev->drmcg_props; + char *cft_name = of_cft(of)->name; + int minor = dev->primary->index; + char *nested = strstrip(attrs); + struct drmcg_device_resource *ddr = + drmcg->dev_resources[minor]; + char *attr; + char sname[256]; + char sval[256]; + s64 val; + int rc; + + while (nested != NULL) { + attr = strsep(&nested, " "); + + if (sscanf(attr, "%255[^=]=%255[^=]", sname, sval) != 2) + continue; + + switch (type) { + case DRMCG_TYPE_LGPU: + if (strncmp(sname, LGPU_LIMITS_NAME_LIST, 256) && + strncmp(sname, LGPU_LIMITS_NAME_COUNT, 256) && + strncmp(sname, LGPU_LIMITS_NAME_WEIGHT, 256)) + continue; + + if (strncmp(sname, LGPU_LIMITS_NAME_WEIGHT, 256) && + (!strcmp("max", sval) || + !strcmp("default", sval))) { + bitmap_copy(ddr->lgpu_cfg, props->lgpu_slots, + props->lgpu_capacity); + + continue; + } + + if (strncmp(sname, LGPU_LIMITS_NAME_WEIGHT, 256) == 0) { + rc = drmcg_process_limit_s64_val(sval, + false, CGROUP_WEIGHT_DFL, + CGROUP_WEIGHT_MAX, &val); + + if (rc || val < CGROUP_WEIGHT_MIN || + val > CGROUP_WEIGHT_MAX) { + drmcg_pr_cft_err(drmcg, rc, cft_name, + minor); + continue; + } + + ddr->lgpu_weight_cfg = val; + continue; + } + + if (strncmp(sname, LGPU_LIMITS_NAME_COUNT, 256) == 0) { + rc = drmcg_process_limit_s64_val(sval, + false, props->lgpu_capacity, + props->lgpu_capacity, &val); + + if (rc || val < 0) { + drmcg_pr_cft_err(drmcg, rc, cft_name, + minor); + continue; + } + + bitmap_zero(tmp_bitmap, + MAX_DRMCG_LGPU_CAPACITY); + bitmap_set(tmp_bitmap, 0, val); + } + + if (strncmp(sname, LGPU_LIMITS_NAME_LIST, 256) == 0) { + rc = bitmap_parselist(sval, tmp_bitmap, + MAX_DRMCG_LGPU_CAPACITY); + + if (rc) { + drmcg_pr_cft_err(drmcg, rc, cft_name, + minor); + continue; + } + + bitmap_andnot(chk_bitmap, tmp_bitmap, + props->lgpu_slots, + MAX_DRMCG_LGPU_CAPACITY); + + /* user setting does not intersect with + * available lgpu */ + if (!bitmap_empty(chk_bitmap, + MAX_DRMCG_LGPU_CAPACITY)) { + drmcg_pr_cft_err(drmcg, 0, cft_name, + minor); + continue; + } + } + + bitmap_copy(ddr->lgpu_cfg, tmp_bitmap, + props->lgpu_capacity); + + break; /* DRMCG_TYPE_LGPU */ + default: + break; + } /* switch (type) */ + } +} + + /** * drmcg_limit_write - parse cgroup interface files to obtain user config * @@ -499,9 +771,15 @@ static ssize_t drmcg_limit_write(struct kernfs_open_file *of, char *buf,
ddr->bo_limits_peak_allocated = val; break; + case DRMCG_TYPE_LGPU: + drmcg_nested_limit_parse(of, dm->dev, sattr); + break; default: break; } + + drmcg_apply_effective(type, dm->dev, drmcg); + mutex_unlock(&dm->dev->drmcg_mutex);
mutex_lock(&drmcg_mutex); @@ -560,12 +838,51 @@ struct cftype files[] = { .private = DRMCG_CTF_PRIV(DRMCG_TYPE_BO_COUNT, DRMCG_FTYPE_STATS), }, + { + .name = "lgpu", + .seq_show = drmcg_seq_show, + .write = drmcg_limit_write, + .private = DRMCG_CTF_PRIV(DRMCG_TYPE_LGPU, + DRMCG_FTYPE_LIMIT), + }, + { + .name = "lgpu.default", + .seq_show = drmcg_seq_show, + .flags = CFTYPE_ONLY_ON_ROOT, + .private = DRMCG_CTF_PRIV(DRMCG_TYPE_LGPU, + DRMCG_FTYPE_DEFAULT), + }, + { + .name = "lgpu.effective", + .seq_show = drmcg_seq_show, + .private = DRMCG_CTF_PRIV(DRMCG_TYPE_LGPU_EFF, + DRMCG_FTYPE_LIMIT), + }, { } /* terminate */ };
+static int drmcg_online_fn(int id, void *ptr, void *data) +{ + struct drm_minor *minor = ptr; + struct drmcg *drmcg = data; + + if (minor->type != DRM_MINOR_PRIMARY) + return 0; + + drmcg_apply_effective(DRMCG_TYPE_LGPU, minor->dev, drmcg); + + return 0; +} + +static int drmcg_css_online(struct cgroup_subsys_state *css) +{ + return drm_minor_for_each(&drmcg_online_fn, css_to_drmcg(css)); +} + struct cgroup_subsys drm_cgrp_subsys = { .css_alloc = drmcg_css_alloc, .css_free = drmcg_css_free, + .css_online = drmcg_css_online, .early_init = false, .legacy_cftypes = files, .dfl_cftypes = files, @@ -585,6 +902,9 @@ void drmcg_device_early_init(struct drm_device *dev) dev->drmcg_props.bo_limits_total_allocated_default = S64_MAX; dev->drmcg_props.bo_limits_peak_allocated_default = S64_MAX;
+ dev->drmcg_props.lgpu_capacity = MAX_DRMCG_LGPU_CAPACITY; + bitmap_fill(dev->drmcg_props.lgpu_slots, MAX_DRMCG_LGPU_CAPACITY); + drmcg_update_cg_tree(dev); } EXPORT_SYMBOL(drmcg_device_early_init);