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.koenig@xxxxxxx>
Cc: Somalapuram Amaranath <Amaranath.Somalapuram@xxxxxxx>
Cc: Matthew Brost <matthew.brost@xxxxxxxxx>
Cc: <dri-devel@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
---
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);
+ if (IS_ERR(tt->backup)) {
+ ttm_tt_fini(tt);
+ kfree(xe_tt);
+ return NULL;
+ }
+
+ return tt;
}
static int xe_ttm_tt_populate(struct ttm_device *ttm_dev, struct ttm_tt *tt,
struct ttm_operation_ctx *ctx)
{
+ struct xe_ttm_tt *xe_tt = container_of(tt, struct xe_ttm_tt, ttm);
int err;
/*
* dma-bufs are not populated with pages, and the dma-
* addresses are set up when moved to XE_PL_TT.
*/
- if (tt->page_flags & TTM_TT_FLAG_EXTERNAL)
+ if ((tt->page_flags & TTM_TT_FLAG_EXTERNAL) &&
+ !(tt->page_flags & TTM_TT_FLAG_EXTERNAL_MAPPABLE))
return 0;
err = ttm_pool_alloc(&ttm_dev->pool, tt, ctx);
if (err)
return err;
- return err;
+ xe_tt->purgeable = false;
+ xe_ttm_tt_account(tt, true);
+
+ return 0;
}
static void xe_ttm_tt_unpopulate(struct ttm_device *ttm_dev, struct ttm_tt *tt)
{
- if (tt->page_flags & TTM_TT_FLAG_EXTERNAL)
+ if ((tt->page_flags & TTM_TT_FLAG_EXTERNAL) &&
+ !(tt->page_flags & TTM_TT_FLAG_EXTERNAL_MAPPABLE))
return;
xe_tt_unmap_sg(tt);
- return ttm_pool_free(&ttm_dev->pool, tt);
+ ttm_pool_free(&ttm_dev->pool, tt);
+ xe_ttm_tt_account(tt, false);
+}
+
+/**
+ * xe_bo_shrink() - Try to shrink an xe bo.
+ * @walk: - The walk parameters
+ * @bo: The TTM buffer object
+ * @purge: Only consider purgeable bos.
+ * @writeback: Try to write back to persistent storage.
+ *
+ * Try to shrink- or purge a bo, and if it succeeds, unmap dma.
+ * Note that we need to be able to handle also non xe bos
+ * (ghost bos), but only if the struct ttm_tt is embedded in
+ * a struct xe_ttm_tt.
+ *
+ * Return: The number of pages shrunken or purged, or negative error
+ * code on failure.
+ */
+long xe_bo_shrink(struct ttm_lru_walk *walk, struct ttm_buffer_object *bo,
+ bool purge, bool writeback)
+{
+ struct ttm_tt *tt = bo->ttm;
+ struct xe_ttm_tt *xe_tt = container_of(tt, struct xe_ttm_tt, ttm);
+ struct ttm_place place = {.mem_type = bo->resource->mem_type};
+ struct xe_bo *xe_bo = ttm_to_xe_bo(bo);
+ struct xe_device *xe = xe_tt->xe;
+ bool needs_rpm;
+ long lret = 0L;
+
+ if (!tt || !ttm_tt_is_populated(tt) ||
+ !(tt->page_flags & TTM_TT_FLAG_EXTERNAL_MAPPABLE) ||
+ (purge && !xe_tt->purgeable))
+ return 0L;
+
+ if (!ttm_bo_eviction_valuable(bo, &place))
+ return 0L;
+
+ /* Beware of zombies (GEM object refcount == 0) and ghosts. */
+ if (!xe_bo_is_xe_bo(bo) || !xe_bo_get_unless_zero(xe_bo)) {
+ struct ttm_placement null_placement = { .num_placement = 0 };
+
+ lret = ttm_bo_wait_ctx(bo, walk->ctx);
+ if (lret)
+ return lret;
+
+ /* Purge the bo content! */
+ ttm_bo_validate(bo, &null_placement, walk->ctx);
+ return tt->num_pages;
+ }
+
+ /* System CCS needs gpu copy when moving PL_TT -> PL_SYSTEM */
+ needs_rpm = (!IS_DGFX(xe) && bo->resource->mem_type != XE_PL_SYSTEM &&
+ xe_bo && xe_bo_needs_ccs_pages(xe_bo) && !xe_tt->purgeable);
+ if (needs_rpm && !xe_pm_runtime_get_if_active(xe))
+ goto out_unref;
+
+ lret = ttm_bo_try_shrink(walk, bo, xe_tt->purgeable, writeback);
+ if (needs_rpm)
+ xe_pm_runtime_put(xe);
+
+ if (lret > 0) {
+ xe_assert(xe, !ttm_tt_is_populated(tt));
+
+ xe_ttm_tt_account(tt, false);
+ }
+
+out_unref:
+ xe_bo_put(xe_bo);
+
+ return lret;
}
static void xe_ttm_tt_destroy(struct ttm_device *ttm_dev, struct ttm_tt *tt)
@@ -1238,6 +1351,7 @@ struct xe_bo *___xe_bo_create_locked(struct xe_device *xe, struct xe_bo *bo,
struct ttm_operation_ctx ctx = {
.interruptible = true,
.no_wait_gpu = false,
+ .gfp_retry_mayfail = true,
};
struct ttm_placement *placement;
uint32_t alignment;
@@ -1681,6 +1795,8 @@ int xe_bo_pin_external(struct xe_bo *bo)
}
ttm_bo_pin(&bo->ttm);
+ if (bo->ttm.ttm && ttm_tt_is_populated(bo->ttm.ttm))
+ xe_ttm_tt_account(bo->ttm.ttm, false);
/*
* FIXME: If we always use the reserve / unreserve functions for locking
@@ -1739,6 +1855,8 @@ int xe_bo_pin(struct xe_bo *bo)
}
ttm_bo_pin(&bo->ttm);
+ if (bo->ttm.ttm && ttm_tt_is_populated(bo->ttm.ttm))
+ xe_ttm_tt_account(bo->ttm.ttm, false);
/*
* FIXME: If we always use the reserve / unreserve functions for locking
@@ -1773,6 +1891,9 @@ void xe_bo_unpin_external(struct xe_bo *bo)
spin_unlock(&xe->pinned.lock);
ttm_bo_unpin(&bo->ttm);
+ if (bo->ttm.ttm && ttm_tt_is_populated(bo->ttm.ttm))
+ xe_ttm_tt_account(bo->ttm.ttm, true);
+
/*
* FIXME: If we always use the reserve / unreserve functions for locking
@@ -1801,6 +1922,8 @@ void xe_bo_unpin(struct xe_bo *bo)
}
ttm_bo_unpin(&bo->ttm);
+ if (bo->ttm.ttm && ttm_tt_is_populated(bo->ttm.ttm))
+ xe_ttm_tt_account(bo->ttm.ttm, true);
}
/**
diff --git a/drivers/gpu/drm/xe/xe_bo.h b/drivers/gpu/drm/xe/xe_bo.h
index 6de894c728f5..8463e3f3f6f1 100644
--- a/drivers/gpu/drm/xe/xe_bo.h
+++ b/drivers/gpu/drm/xe/xe_bo.h
@@ -63,6 +63,7 @@
#define XE_BO_PROPS_INVALID (-1)
struct sg_table;
+struct xe_ttm_lru_walk;
struct xe_bo *xe_bo_alloc(void);
void xe_bo_free(struct xe_bo *bo);
@@ -126,6 +127,28 @@ static inline struct xe_bo *xe_bo_get(struct xe_bo *bo)
return bo;
}
+/*
+ * xe_bo_get_unless_zero() - Conditionally obtain a GEM object refcount on an
+ * xe bo
+ * @bo: The bo for which we want to obtain a refcount.
+ *
+ * There is a short window between where the bo's GEM object refcount reaches
+ * zero and where we put the final ttm_bo reference. Code in the eviction- and
+ * shrinking path should therefore attempt to grab a gem object reference before
+ * trying to use members outside of the base class ttm object. This function is
+ * intended for that purpose. On successful return, this function must be paired
+ * with an xe_bo_put().
+ *
+ * Return: @bo on success, NULL on failure.
+ */
+static inline __must_check struct xe_bo *xe_bo_get_unless_zero(struct xe_bo *bo)
+{
+ if (!bo || !kref_get_unless_zero(&bo->ttm.base.refcount))
+ return NULL;
+
+ return bo;
+}
+
static inline void xe_bo_put(struct xe_bo *bo)
{
if (bo)
@@ -315,6 +338,9 @@ static inline unsigned int xe_sg_segment_size(struct device *dev)
#define i915_gem_object_flush_if_display(obj) ((void)(obj))
+long xe_bo_shrink(struct ttm_lru_walk *walk, struct ttm_buffer_object *bo,
+ bool purge, bool writeback);
+
#if IS_ENABLED(CONFIG_DRM_XE_KUNIT_TEST)
/**
* xe_bo_is_mem_type - Whether the bo currently resides in the given
diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
index cfda7cb5df2c..58fecc4b0a18 100644
--- a/drivers/gpu/drm/xe/xe_device.c
+++ b/drivers/gpu/drm/xe/xe_device.c
@@ -47,6 +47,7 @@
#include "xe_perf.h"
#include "xe_pm.h"
#include "xe_query.h"
+#include "xe_shrinker.h"
#include "xe_sriov.h"
#include "xe_tile.h"
#include "xe_ttm_stolen_mgr.h"
@@ -241,6 +242,9 @@ static void xe_device_destroy(struct drm_device *dev, void *dummy)
if (xe->unordered_wq)
destroy_workqueue(xe->unordered_wq);
+ if (!IS_ERR_OR_NULL(xe->mem.shrinker))
+ xe_shrinker_destroy(xe->mem.shrinker);
+
ttm_device_fini(&xe->ttm);
}
@@ -270,6 +274,10 @@ struct xe_device *xe_device_create(struct pci_dev *pdev,
if (err)
goto err;
+ xe->mem.shrinker = xe_shrinker_create(xe);
+ if (IS_ERR(xe->mem.shrinker))
+ return ERR_CAST(xe->mem.shrinker);
+
xe->info.devid = pdev->device;
xe->info.revid = pdev->revision;
xe->info.force_execlist = xe_modparam.force_execlist;
diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
index c37be471d11c..3d5440aba52e 100644
--- a/drivers/gpu/drm/xe/xe_device_types.h
+++ b/drivers/gpu/drm/xe/xe_device_types.h
@@ -325,6 +325,8 @@ struct xe_device {
struct xe_mem_region vram;
/** @mem.sys_mgr: system TTM manager */
struct ttm_resource_manager sys_mgr;
+ /** @mem.sys_mgr: system memory shrinker. */
+ struct xe_shrinker *shrinker;
} mem;
/** @sriov: device level virtualization data */
diff --git a/drivers/gpu/drm/xe/xe_shrinker.c b/drivers/gpu/drm/xe/xe_shrinker.c
new file mode 100644
index 000000000000..3f9554bdc06b
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_shrinker.c
@@ -0,0 +1,287 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2024 Intel Corporation
+ */
+
+#include <linux/shrinker.h>
+#include <linux/swap.h>
+
+#include <drm/ttm/ttm_bo.h>
+#include <drm/ttm/ttm_tt.h>
+
+#include "xe_bo.h"
+#include "xe_pm.h"
+#include "xe_shrinker.h"
+
+/**
+ * struct xe_shrinker - per-device shrinker
+ * @xe: Back pointer to the device.
+ * @lock: Lock protecting accounting.
+ * @shrinkable_pages: Number of pages that are currently shrinkable.
+ * @purgeable_pages: Number of pages that are currently purgeable.
+ * @shrink: Pointer to the mm shrinker.
+ * @pm_worker: Worker to wake up the device if required.
+ */
+struct xe_shrinker {
+ struct xe_device *xe;
+ rwlock_t lock;
+ long shrinkable_pages;
+ long purgeable_pages;
+ struct shrinker *shrink;
+ struct work_struct pm_worker;
+};
+
+/**
+ * struct xe_shrink_lru_walk - lru_walk subclass for shrinker
+ * @walk: The embedded base class.
+ * @xe: Pointer to the xe device.
+ * @purge: Purgeable only request from the srinker.
+ * @writeback: Try to write back to persistent storage.
+ */
+struct xe_shrink_lru_walk {
+ struct ttm_lru_walk walk;
+ struct xe_device *xe;
+ bool purge;
+ bool writeback;
+};
+
+static struct xe_shrinker *to_xe_shrinker(struct shrinker *shrink)
+{
+ return shrink->private_data;
+}
+
+static struct xe_shrink_lru_walk *
+to_xe_shrink_lru_walk(struct ttm_lru_walk *walk)
+{
+ return container_of(walk, struct xe_shrink_lru_walk, walk);
+}
+
+/**
+ * xe_shrinker_mod_pages() - Modify shrinker page accounting
+ * @shrinker: Pointer to the struct xe_shrinker.
+ * @shrinkable: Shrinkable pages delta. May be negative.
+ * @purgeable: Purgeable page delta. May be negative.
+ *
+ * Modifies the shrinkable and purgeable pages accounting.
+ */
+void
+xe_shrinker_mod_pages(struct xe_shrinker *shrinker, long shrinkable, long purgeable)
+{
+ write_lock(&shrinker->lock);
+ shrinker->shrinkable_pages += shrinkable;
+ shrinker->purgeable_pages += purgeable;
+ write_unlock(&shrinker->lock);
+}
+
+static long xe_shrinker_process_bo(struct ttm_lru_walk *walk, struct ttm_buffer_object *bo)
+{
+ struct xe_shrink_lru_walk *shrink_walk = to_xe_shrink_lru_walk(walk);
+
+ return xe_bo_shrink(walk, bo, shrink_walk->purge, shrink_walk->writeback);
+}
+
+static long xe_shrinker_walk(struct xe_shrink_lru_walk *shrink_walk, long target)
+{
+ struct xe_device *xe = shrink_walk->xe;
+ struct ttm_resource_manager *man;
+ unsigned int mem_type;
+ long sofar = 0;
+ long lret;
+
+ for (mem_type = XE_PL_SYSTEM; mem_type <= XE_PL_TT; ++mem_type) {
+ man = ttm_manager_type(&xe->ttm, mem_type);
+ if (!man || !man->use_tt)
+ continue;
+
+ lret = ttm_lru_walk_for_evict(&shrink_walk->walk, &xe->ttm, man, target);
+ if (lret < 0)
+ return lret;
+
+ sofar += lret;
+ if (sofar >= target)
+ break;
+ }
+
+ return sofar;
+}
+
+static unsigned long
+xe_shrinker_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+ struct xe_shrinker *shrinker = to_xe_shrinker(shrink);
+ unsigned long num_pages;
+
+ num_pages = get_nr_swap_pages();
+ read_lock(&shrinker->lock);
+ num_pages = min_t(unsigned long, num_pages, shrinker->shrinkable_pages);
+ num_pages += shrinker->purgeable_pages;
+ read_unlock(&shrinker->lock);
+
+ return num_pages ? num_pages : SHRINK_EMPTY;
+}
+
+static const struct ttm_lru_walk_ops xe_shrink_ops = {
+ .process_bo = xe_shrinker_process_bo,
+};
+
+/*
+ * Check if we need runtime pm, and if so try to grab a reference if
+ * already active. If grabbing a reference fails, queue a worker that
+ * does it for us outside of reclaim, but don't wait for it to complete.
+ * If bo shrinking needs an rpm reference and we don't have it (yet),
+ * that bo will be skipped anyway.
+ */
+static bool xe_shrinker_runtime_pm_get(struct xe_shrinker *shrinker, bool force,
+ unsigned long nr_to_scan)
+{
+ struct xe_device *xe = shrinker->xe;
+
+ if (IS_DGFX(xe) || !xe_device_has_flat_ccs(xe) ||
+ !get_nr_swap_pages())
+ return false;
+
+ if (!force) {
+ read_lock(&shrinker->lock);
+ force = (nr_to_scan > shrinker->purgeable_pages);
+ read_unlock(&shrinker->lock);
+ if (!force)
+ return false;
+ }
+
+ if (!xe_pm_runtime_get_if_active(xe)) {
+ queue_work(xe->unordered_wq, &shrinker->pm_worker);
+ return false;
+ }
+
+ return true;
+}
+
+static void xe_shrinker_runtime_pm_put(struct xe_shrinker *shrinker, bool runtime_pm)
+{
+ if (runtime_pm)
+ xe_pm_runtime_put(shrinker->xe);
+}
+
+static unsigned long xe_shrinker_scan(struct shrinker *shrink, struct shrink_control *sc)
+{
+ struct xe_shrinker *shrinker = to_xe_shrinker(shrink);
+ bool is_kswapd = current_is_kswapd();
+ struct ttm_operation_ctx ctx = {
+ .interruptible = false,
+ .no_wait_gpu = !is_kswapd,
+ };
+ unsigned long nr_to_scan, freed = 0;
+ struct xe_shrink_lru_walk shrink_walk = {
+ .walk = {
+ .ops = &xe_shrink_ops,
+ .ctx = &ctx,
+ .trylock_only = true,
+ },
+ .xe = shrinker->xe,
+ .purge = true,
+ .writeback = is_kswapd,
+ };
+ bool runtime_pm;
+ bool purgeable;
+ long ret;
+
+ sc->nr_scanned = 0;
+ nr_to_scan = sc->nr_to_scan;
+
+ read_lock(&shrinker->lock);
+ purgeable = !!shrinker->purgeable_pages;
+ read_unlock(&shrinker->lock);
+
+ /* Might need runtime PM. Try to wake early if it looks like it. */
+ runtime_pm = xe_shrinker_runtime_pm_get(shrinker, false, nr_to_scan);
+
+ while (purgeable && freed < nr_to_scan) {
+ ret = xe_shrinker_walk(&shrink_walk, nr_to_scan);
+ if (ret <= 0)
+ break;
+
+ freed += ret;
+ }
+
+ sc->nr_scanned = freed;
+ if (freed < nr_to_scan)
+ nr_to_scan -= freed;
+ else
+ nr_to_scan = 0;
+ if (!nr_to_scan)
+ goto out;
+
+ /* If we didn't wake before, try to do it now if needed. */
+ if (!runtime_pm)
+ runtime_pm = xe_shrinker_runtime_pm_get(shrinker, true, 0);
+
+ shrink_walk.purge = false;
+ nr_to_scan = sc->nr_to_scan;
+ while (freed < nr_to_scan) {
+ ret = xe_shrinker_walk(&shrink_walk, nr_to_scan);
+ if (ret <= 0)
+ break;
+
+ freed += ret;
+ }
+
+ sc->nr_scanned = freed;
+
+out:
+ xe_shrinker_runtime_pm_put(shrinker, runtime_pm);
+ return freed ? freed : SHRINK_STOP;
+}
+
+/* Wake up the device for shrinking. */
+static void xe_shrinker_pm(struct work_struct *work)
+{
+ struct xe_shrinker *shrinker =
+ container_of(work, typeof(*shrinker), pm_worker);
+
+ xe_pm_runtime_get(shrinker->xe);
+ xe_pm_runtime_put(shrinker->xe);
+}
+
+/**
+ * xe_shrinker_create() - Create an xe per-device shrinker
+ * @xe: Pointer to the xe device.
+ *
+ * Returns: A pointer to the created shrinker on success,
+ * Negative error code on failure.
+ */
+struct xe_shrinker *xe_shrinker_create(struct xe_device *xe)
+{
+ struct xe_shrinker *shrinker = kzalloc(sizeof(*shrinker), GFP_KERNEL);
+
+ if (!shrinker)
+ return ERR_PTR(-ENOMEM);
+
+ shrinker->shrink = shrinker_alloc(0, "xe system shrinker");
+ if (!shrinker->shrink) {
+ kfree(shrinker);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ INIT_WORK(&shrinker->pm_worker, xe_shrinker_pm);
+ shrinker->xe = xe;
+ rwlock_init(&shrinker->lock);
+ shrinker->shrink->count_objects = xe_shrinker_count;
+ shrinker->shrink->scan_objects = xe_shrinker_scan;
+ shrinker->shrink->private_data = shrinker;
+ shrinker_register(shrinker->shrink);
+
+ return shrinker;
+}
+
+/**
+ * xe_shrinker_destroy() - Destroy an xe per-device shrinker
+ * @shrinker: Pointer to the shrinker to destroy.
+ */
+void xe_shrinker_destroy(struct xe_shrinker *shrinker)
+{
+ xe_assert(shrinker->xe, !shrinker->shrinkable_pages);
+ xe_assert(shrinker->xe, !shrinker->purgeable_pages);
+ shrinker_free(shrinker->shrink);
+ flush_work(&shrinker->pm_worker);
+ kfree(shrinker);
+}
diff --git a/drivers/gpu/drm/xe/xe_shrinker.h b/drivers/gpu/drm/xe/xe_shrinker.h
new file mode 100644
index 000000000000..28a038f4fcbf
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_shrinker.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2024 Intel Corporation
+ */
+
+#ifndef _XE_SHRINKER_H_
+#define _XE_SHRINKER_H_
+
+struct xe_shrinker;
+struct xe_device;
+
+void xe_shrinker_mod_pages(struct xe_shrinker *shrinker, long shrinkable, long purgeable);
+
+struct xe_shrinker *xe_shrinker_create(struct xe_device *xe);
+
+void xe_shrinker_destroy(struct xe_shrinker *shrinker);
+
+#endif
diff --git a/include/drm/ttm/ttm_bo.h b/include/drm/ttm/ttm_bo.h
index e577528f5dfc..c7e81ae025d9 100644
--- a/include/drm/ttm/ttm_bo.h
+++ b/include/drm/ttm/ttm_bo.h
@@ -229,6 +229,9 @@ struct ttm_lru_walk {
long ttm_lru_walk_for_evict(struct ttm_lru_walk *walk, struct ttm_device *bdev,
struct ttm_resource_manager *man, long target);
+long ttm_bo_try_shrink(struct ttm_lru_walk *walk, struct ttm_buffer_object *bo,
+ bool purge, bool writeback);
+
/**
* ttm_bo_get - reference a struct ttm_buffer_object
*
--
2.44.0
