Rather than relying on the TTM watermark accounting add a shrinker
for xe_bos in TT or system memory.
Leverage the newly added TTM per-page shrinking and shmem backup
support.
Although xe doesn't fully support WONTNEED (purgeable) bos yet,
introduce and add shrinker support for purgeable ttm_tts.
v2:
- Cleanups bugfixes and a KUNIT shrinker test.
- Add writeback support, and activate if kswapd.
v3:
- Move the try_shrink() helper to core TTM.
- Minor cleanups.
v4:
- Add runtime pm for the shrinker. Shrinking may require an active
device for CCS metadata copying.
v5:
- Separately purge ghost- and zombie objects in the shrinker.
- Fix a format specifier - type inconsistency. (Kernel test robot).
Cc: Christian König <christian.koe...@amd.com>
Cc: Somalapuram Amaranath <amaranath.somalapu...@amd.com>
Cc: Matthew Brost <matthew.br...@intel.com>
Cc: <dri-devel@lists.freedesktop.org>
Signed-off-by: Thomas Hellström <thomas.hellst...@linux.intel.com>
---
drivers/gpu/drm/ttm/ttm_bo_util.c | 67 ++++++
drivers/gpu/drm/xe/Makefile | 1 +
drivers/gpu/drm/xe/tests/xe_bo.c | 118 +++++++++++
drivers/gpu/drm/xe/tests/xe_bo_test.c | 1 +
drivers/gpu/drm/xe/tests/xe_bo_test.h | 1 +
drivers/gpu/drm/xe/xe_bo.c | 155 ++++++++++++--
drivers/gpu/drm/xe/xe_bo.h | 26 +++
drivers/gpu/drm/xe/xe_device.c | 8 +
drivers/gpu/drm/xe/xe_device_types.h | 2 +
drivers/gpu/drm/xe/xe_shrinker.c | 287 ++++++++++++++++++++++++++
drivers/gpu/drm/xe/xe_shrinker.h | 18 ++
include/drm/ttm/ttm_bo.h | 3 +
12 files changed, 671 insertions(+), 16 deletions(-)
create mode 100644 drivers/gpu/drm/xe/xe_shrinker.c
create mode 100644 drivers/gpu/drm/xe/xe_shrinker.h
diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c
b/drivers/gpu/drm/ttm/ttm_bo_util.c
index c4f678f30fc2..563e96a4cf06 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -924,3 +924,70 @@ long ttm_lru_walk_for_evict(struct ttm_lru_walk *walk,
struct ttm_device *bdev,
return progress;
}
+EXPORT_SYMBOL(ttm_lru_walk_for_evict);
+
+/**
+ * ttm_bo_try_shrink - LRU walk helper to shrink a ttm buffer object.
+ * @walk: The struct xe_ttm_lru_walk that describes the walk.
+ * @bo: The buffer object.
+ * @purge: Whether to attempt to purge the bo content since it's no
+ * longer needed.
+ * @writeback: If !@purge, attempt to write out to persistent storage.
+ *
+ * The function uses the ttm_tt_back_up functionality to back up or
+ * purge a struct ttm_tt. If the bo is not in system, it's first
+ * moved there.
+ *
+ * Return: The number of pages shrunken or purged, or
+ * negative error code on failure.
+ */
+long ttm_bo_try_shrink(struct ttm_lru_walk *walk, struct ttm_buffer_object *bo,
+ bool purge, bool writeback)
+{
+ static const struct ttm_place sys_placement_flags = {
+ .fpfn = 0,
+ .lpfn = 0,
+ .mem_type = TTM_PL_SYSTEM,
+ .flags = 0,
+ };
+ static struct ttm_placement sys_placement = {
+ .num_placement = 1,
+ .placement = &sys_placement_flags,
+ };
+ struct ttm_operation_ctx *ctx = walk->ctx;
+ struct ttm_tt *tt = bo->ttm;
+ long lret;
+
+ dma_resv_assert_held(bo->base.resv);
+
+ if (!tt || !ttm_tt_is_populated(tt))
+ return 0;
+
+ if (bo->resource->mem_type != TTM_PL_SYSTEM) {
+ int ret = ttm_bo_validate(bo, &sys_placement, ctx);
+
+ if (ret) {
+ if (ret == -EINTR || ret == -EDEADLK ||
+ ret == -ERESTARTSYS)
+ return ret;
+ return 0;
+ }
+ }
+
+ lret = ttm_bo_wait_ctx(bo, ctx);
+ if (lret < 0) {
+ if (lret == -ERESTARTSYS)
+ return lret;
+ return 0;
+ }
+
+ if (bo->deleted)
+ lret = ttm_tt_backup(bo->bdev, tt, true, writeback);
+ else
+ lret = ttm_tt_backup(bo->bdev, tt, purge, writeback);
+ if (lret < 0 && lret != -EINTR)
+ return 0;
+
+ return lret;
+}
+EXPORT_SYMBOL(ttm_bo_try_shrink);
diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
index b1e03bfe4a68..1eba51bdd172 100644
--- a/drivers/gpu/drm/xe/Makefile
+++ b/drivers/gpu/drm/xe/Makefile
@@ -112,6 +112,7 @@ xe-y += xe_bb.o \
xe_ring_ops.o \
xe_sa.o \
xe_sched_job.o \
+ xe_shrinker.o \
xe_step.o \
xe_sync.o \
xe_tile.o \
diff --git a/drivers/gpu/drm/xe/tests/xe_bo.c b/drivers/gpu/drm/xe/tests/xe_bo.c
index 9f3c02826464..49617f16dc76 100644
--- a/drivers/gpu/drm/xe/tests/xe_bo.c
+++ b/drivers/gpu/drm/xe/tests/xe_bo.c
@@ -6,6 +6,8 @@
#include <kunit/test.h>
#include <kunit/visibility.h>
+#include <uapi/linux/sysinfo.h>
+
#include "tests/xe_bo_test.h"
#include "tests/xe_pci_test.h"
#include "tests/xe_test.h"
@@ -350,3 +352,119 @@ void xe_bo_evict_kunit(struct kunit *test)
xe_call_for_each_device(evict_test_run_device);
}
EXPORT_SYMBOL_IF_KUNIT(xe_bo_evict_kunit);
+
+struct xe_bo_link {
+ struct list_head link;
+ struct xe_bo *bo;
+};
+
+#define XE_BO_SHRINK_SIZE ((unsigned long)SZ_64M)
+
+/*
+ * Try to create system bos corresponding to twice the amount
+ * of available system memory to test shrinker functionality.
+ * If no swap space is available to accommodate the
+ * memory overcommit, mark bos purgeable.
+ */
+static int shrink_test_run_device(struct xe_device *xe)
+{
+ struct kunit *test = xe_cur_kunit();
+ LIST_HEAD(bos);
+ struct xe_bo_link *link, *next;
+ struct sysinfo si;
+ size_t total, alloced;
+ unsigned int interrupted = 0, successful = 0;
+
+ si_meminfo(&si);
+ total = si.freeram * si.mem_unit;
+
+ kunit_info(test, "Free ram is %lu bytes. Will allocate twice of
that.\n",
+ (unsigned long) total);
+
+ total <<= 1;
+ for (alloced = 0; alloced < total ; alloced += XE_BO_SHRINK_SIZE) {
+ struct xe_bo *bo;
+ unsigned int mem_type;
+
+ link = kzalloc(sizeof(*link), GFP_KERNEL);
+ if (!link) {
+ KUNIT_FAIL(test, "Unexpeced link allocation failure\n");
+ break;
+ }
+
+ INIT_LIST_HEAD(&link->link);
+
+ /* We can create bos using WC caching here. But it is slower. */
+ bo = xe_bo_create_user(xe, NULL, NULL, XE_BO_SHRINK_SIZE,
+ DRM_XE_GEM_CPU_CACHING_WB,
+ ttm_bo_type_device,
+ XE_BO_FLAG_SYSTEM);
+ if (IS_ERR(bo)) {
+ if (bo != ERR_PTR(-ENOMEM) && bo != ERR_PTR(-ENOSPC) &&
+ bo != ERR_PTR(-EINTR) && bo !=
ERR_PTR(-ERESTARTSYS))
+ KUNIT_FAIL(test, "Error creating bo: %pe\n",
bo);
+ kfree(link);
+ break;
+ }
+ link->bo = bo;
+ list_add_tail(&link->link, &bos);
+ xe_bo_lock(bo, false);
+
+ /*
+ * If we're low on swap entries, we can't shrink unless the bo
+ * is marked purgeable.
+ */
+ if (get_nr_swap_pages() < (XE_BO_SHRINK_SIZE >> PAGE_SHIFT) *
128) {
+ struct xe_ttm_tt *xe_tt =
+ container_of(bo->ttm.ttm, typeof(*xe_tt), ttm);
+ long num_pages = xe_tt->ttm.num_pages;
+
+ xe_tt->purgeable = true;
+ xe_shrinker_mod_pages(xe->mem.shrinker, -num_pages,
+ num_pages);
+ }
+
+ mem_type = bo->ttm.resource->mem_type;
+ xe_bo_unlock(bo);
+ if (mem_type != XE_PL_TT)
+ KUNIT_FAIL(test, "Bo in incorrect memory type: %u\n",
+ bo->ttm.resource->mem_type);
+ cond_resched();
+ if (signal_pending(current))
+ break;
+ }
+
+ /* Read back and destroy bos */
+ list_for_each_entry_safe_reverse(link, next, &bos, link) {
+ static struct ttm_operation_ctx ctx = {.interruptible = true};
+ struct xe_bo *bo = link->bo;
+ int ret;
+
+ if (!signal_pending(current)) {
+ xe_bo_lock(bo, NULL);
+ ret = ttm_bo_validate(&bo->ttm, &tt_placement, &ctx);
+ xe_bo_unlock(bo);
+ if (ret && ret != -EINTR)
+ KUNIT_FAIL(test, "Validation failed: %pe\n",
+ ERR_PTR(ret));
+ else if (ret)
+ interrupted++;
+ else
+ successful++;
+ }
+ xe_bo_put(link->bo);
+ list_del(&link->link);
+ kfree(link);
+ cond_resched();
+ }
+ kunit_info(test, "Readbacks interrupted: %u successful: %u\n",
+ interrupted, successful);
+
+ return 0;
+}
+
+void xe_bo_shrink_kunit(struct kunit *test)
+{
+ xe_call_for_each_device(shrink_test_run_device);
+}
+EXPORT_SYMBOL_IF_KUNIT(xe_bo_shrink_kunit);
diff --git a/drivers/gpu/drm/xe/tests/xe_bo_test.c
b/drivers/gpu/drm/xe/tests/xe_bo_test.c
index a324cde77db8..317fa923e287 100644
--- a/drivers/gpu/drm/xe/tests/xe_bo_test.c
+++ b/drivers/gpu/drm/xe/tests/xe_bo_test.c
@@ -10,6 +10,7 @@
static struct kunit_case xe_bo_tests[] = {
KUNIT_CASE(xe_ccs_migrate_kunit),
KUNIT_CASE(xe_bo_evict_kunit),
+ KUNIT_CASE_SLOW(xe_bo_shrink_kunit),
{}
};
diff --git a/drivers/gpu/drm/xe/tests/xe_bo_test.h b/drivers/gpu/drm/xe/tests/xe_bo_test.h
index 0113ab45066a..7f44d14a45c5 100644
--- a/drivers/gpu/drm/xe/tests/xe_bo_test.h
+++ b/drivers/gpu/drm/xe/tests/xe_bo_test.h
@@ -10,5 +10,6 @@ struct kunit;
void xe_ccs_migrate_kunit(struct kunit *test);
void xe_bo_evict_kunit(struct kunit *test);
+void xe_bo_shrink_kunit(struct kunit *test);
#endif
diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c
index 65c696966e96..6ab63d1642ae 100644
--- a/drivers/gpu/drm/xe/xe_bo.c
+++ b/drivers/gpu/drm/xe/xe_bo.c
@@ -10,6 +10,7 @@
#include <drm/drm_drv.h>
#include <drm/drm_gem_ttm_helper.h>
#include <drm/drm_managed.h>
+#include <drm/ttm/ttm_backup.h>
#include <drm/ttm/ttm_device.h>
#include <drm/ttm/ttm_placement.h>
#include <drm/ttm/ttm_tt.h>
@@ -25,6 +26,7 @@
#include "xe_pm.h"
#include "xe_preempt_fence.h"
#include "xe_res_cursor.h"
+#include "xe_shrinker.h"
#include "xe_trace_bo.h"
#include "xe_ttm_stolen_mgr.h"
#include "xe_vm.h"
@@ -278,11 +280,15 @@ static void xe_evict_flags(struct ttm_buffer_object *tbo,
}
}
+/* struct xe_ttm_tt - Subclassed ttm_tt for xe */
struct xe_ttm_tt {
struct ttm_tt ttm;
- struct device *dev;
+ /** @xe - The xe device */
+ struct xe_device *xe;
struct sg_table sgt;
struct sg_table *sg;
+ /** @purgeable - Whether the bo is purgeable (WONTNEED) */
+ bool purgeable;
};
static int xe_tt_map_sg(struct ttm_tt *tt)
@@ -291,7 +297,8 @@ static int xe_tt_map_sg(struct ttm_tt *tt)
unsigned long num_pages = tt->num_pages;
int ret;
- XE_WARN_ON(tt->page_flags & TTM_TT_FLAG_EXTERNAL);
+ XE_WARN_ON((tt->page_flags & TTM_TT_FLAG_EXTERNAL) &&
+ !(tt->page_flags & TTM_TT_FLAG_EXTERNAL_MAPPABLE));
if (xe_tt->sg)
return 0;
@@ -299,13 +306,13 @@ static int xe_tt_map_sg(struct ttm_tt *tt)
ret = sg_alloc_table_from_pages_segment(&xe_tt->sgt, tt->pages,
num_pages, 0,
(u64)num_pages << PAGE_SHIFT,
- xe_sg_segment_size(xe_tt->dev),
+
xe_sg_segment_size(xe_tt->xe->drm.dev),
GFP_KERNEL);
if (ret)
return ret;
xe_tt->sg = &xe_tt->sgt;
- ret = dma_map_sgtable(xe_tt->dev, xe_tt->sg, DMA_BIDIRECTIONAL,
+ ret = dma_map_sgtable(xe_tt->xe->drm.dev, xe_tt->sg, DMA_BIDIRECTIONAL,
DMA_ATTR_SKIP_CPU_SYNC);
if (ret) {
sg_free_table(xe_tt->sg);
@@ -321,7 +328,7 @@ static void xe_tt_unmap_sg(struct ttm_tt *tt)
struct xe_ttm_tt *xe_tt = container_of(tt, struct xe_ttm_tt, ttm);
if (xe_tt->sg) {
- dma_unmap_sgtable(xe_tt->dev, xe_tt->sg,
+ dma_unmap_sgtable(xe_tt->xe->drm.dev, xe_tt->sg,
DMA_BIDIRECTIONAL, 0);
sg_free_table(xe_tt->sg);
xe_tt->sg = NULL;
@@ -336,21 +343,41 @@ struct sg_table *xe_bo_sg(struct xe_bo *bo)
return xe_tt->sg;
}
+/*
+ * Account ttm pages against the device shrinker's shrinkable and
+ * purgeable counts.
+ */
+static void xe_ttm_tt_account(struct ttm_tt *tt, bool add)
+{
+ struct xe_ttm_tt *xe_tt = container_of(tt, struct xe_ttm_tt, ttm);
+ long num_pages = tt->num_pages;
+
+ if (!add)
+ num_pages = -num_pages;
+
+ if (xe_tt->purgeable)
+ xe_shrinker_mod_pages(xe_tt->xe->mem.shrinker, 0, num_pages);
+ else
+ xe_shrinker_mod_pages(xe_tt->xe->mem.shrinker, num_pages, 0);
+}
+
static struct ttm_tt *xe_ttm_tt_create(struct ttm_buffer_object *ttm_bo,
u32 page_flags)
{
struct xe_bo *bo = ttm_to_xe_bo(ttm_bo);
struct xe_device *xe = xe_bo_device(bo);
- struct xe_ttm_tt *tt;
+ struct xe_ttm_tt *xe_tt;
+ struct ttm_tt *tt;
unsigned long extra_pages;
enum ttm_caching caching;
int err;
- tt = kzalloc(sizeof(*tt), GFP_KERNEL);
- if (!tt)
+ xe_tt = kzalloc(sizeof(*xe_tt), GFP_KERNEL);
+ if (!xe_tt)
return NULL;
- tt->dev = xe->drm.dev;
+ tt = &xe_tt->ttm;
+ xe_tt->xe = xe;
extra_pages = 0;
if (xe_bo_needs_ccs_pages(bo))
@@ -387,42 +414,128 @@ static struct ttm_tt *xe_ttm_tt_create(struct
ttm_buffer_object *ttm_bo,
caching = ttm_uncached;
}
- err = ttm_tt_init(&tt->ttm, &bo->ttm, page_flags, caching, extra_pages);
+ if (ttm_bo->type != ttm_bo_type_sg)
+ page_flags |= TTM_TT_FLAG_EXTERNAL |
TTM_TT_FLAG_EXTERNAL_MAPPABLE;
+
+ err = ttm_tt_init(tt, &bo->ttm, page_flags, caching, extra_pages);
if (err) {
- kfree(tt);
+ kfree(xe_tt);
return NULL;
}
- return &tt->ttm;
+ tt->backup = ttm_backup_shmem_create(tt->num_pages << PAGE_SHIFT);
