Linaro-mm-sig December 2024

linaro-mm-sig@lists.linaro.org

11 participants
22 discussions

[PATCH 6.12 187/466] dma-fence: Use kernels sort for merging fences

by Greg Kroah-Hartman

6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tvrtko Ursulin <tvrtko.ursulin(a)igalia.com> commit fe52c649438b8489c9456681d93a9b3de3d38263 upstream. One alternative to the fix Christian proposed in https://lore.kernel.org/dri-devel/20241024124159.4519-3-christian.koenig@am… is to replace the rather complex open coded sorting loops with the kernel standard sort followed by a context squashing pass. Proposed advantage of this would be readability but one concern Christian raised was that there could be many fences, that they are typically mostly sorted, and so the kernel's heap sort would be much worse by the proposed algorithm. I had a look running some games and vkcube to see what are the typical number of input fences. Tested scenarios: 1) Hogwarts Legacy under Gamescope 450 calls per second to __dma_fence_unwrap_merge. Percentages per number of fences buckets, before and after checking for signalled status, sorting and flattening: N Before After 0 0.91% 1 69.40% 2-3 28.72% 9.4% (90.6% resolved to one fence) 4-5 0.93% 6-9 0.03% 10+ 2) Cyberpunk 2077 under Gamescope 1050 calls per second, amounting to 0.01% CPU time according to perf top. N Before After 0 1.13% 1 52.30% 2-3 40.34% 55.57% 4-5 1.46% 0.50% 6-9 2.44% 10+ 2.34% 3) vkcube under Plasma 90 calls per second. N Before After 0 1 2-3 100% 0% (Ie. all resolved to a single fence) 4-5 6-9 10+ In the case of vkcube all invocations in the 2-3 bucket were actually just two input fences. >From these numbers it looks like the heap sort should not be a disadvantage, given how the dominant case is <= 2 input fences which heap sort solves with just one compare and swap. (And for the case of one input fence we have a fast path in the previous patch.) A complementary possibility is to implement a different sorting algorithm under the same API as the kernel's sort() and so keep the simplicity, potentially moving the new sort under lib/ if it would be found more widely useful. v2: * Hold on to fence references and reduce commentary. (Christian) * Record and use latest signaled timestamp in the 2nd loop too. * Consolidate zero or one fences fast paths. v3: * Reverse the seqno sort order for a simpler squashing pass. (Christian) Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin(a)igalia.com> Fixes: 245a4a7b531c ("dma-buf: generalize dma_fence unwrap & merging v3") Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3617 Cc: Christian König <christian.koenig(a)amd.com> Cc: Daniel Vetter <daniel.vetter(a)ffwll.ch> Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: Gustavo Padovan <gustavo(a)padovan.org> Cc: Friedrich Vock <friedrich.vock(a)gmx.de> Cc: linux-media(a)vger.kernel.org Cc: dri-devel(a)lists.freedesktop.org Cc: linaro-mm-sig(a)lists.linaro.org Cc: <stable(a)vger.kernel.org> # v6.0+ Reviewed-by: Christian König <christian.koenig(a)amd.com> Signed-off-by: Christian König <christian.koenig(a)amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20241115102153.1980-3-tursuli… Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/dma-buf/dma-fence-unwrap.c | 126 +++++++++++++++++-------------------- 1 file changed, 60 insertions(+), 66 deletions(-) --- a/drivers/dma-buf/dma-fence-unwrap.c +++ b/drivers/dma-buf/dma-fence-unwrap.c @@ -12,6 +12,7 @@ #include <linux/dma-fence-chain.h> #include <linux/dma-fence-unwrap.h> #include <linux/slab.h> +#include <linux/sort.h> /* Internal helper to start new array iteration, don't use directly */ static struct dma_fence * @@ -59,6 +60,25 @@ struct dma_fence *dma_fence_unwrap_next( } EXPORT_SYMBOL_GPL(dma_fence_unwrap_next); + +static int fence_cmp(const void *_a, const void *_b) +{ + struct dma_fence *a = *(struct dma_fence **)_a; + struct dma_fence *b = *(struct dma_fence **)_b; + + if (a->context < b->context) + return -1; + else if (a->context > b->context) + return 1; + + if (dma_fence_is_later(b, a)) + return 1; + else if (dma_fence_is_later(a, b)) + return -1; + + return 0; +} + /* Implementation for the dma_fence_merge() marco, don't use directly */ struct dma_fence *__dma_fence_unwrap_merge(unsigned int num_fences, struct dma_fence **fences, @@ -67,8 +87,7 @@ struct dma_fence *__dma_fence_unwrap_mer struct dma_fence_array *result; struct dma_fence *tmp, **array; ktime_t timestamp; - unsigned int i; - size_t count; + int i, j, count; count = 0; timestamp = ns_to_ktime(0); @@ -96,80 +115,55 @@ struct dma_fence *__dma_fence_unwrap_mer if (!array) return NULL; - /* - * This trashes the input fence array and uses it as position for the - * following merge loop. This works because the dma_fence_merge() - * wrapper macro is creating this temporary array on the stack together - * with the iterators. - */ - for (i = 0; i < num_fences; ++i) - fences[i] = dma_fence_unwrap_first(fences[i], &iter[i]); - count = 0; - do { - unsigned int sel; - -restart: - tmp = NULL; - for (i = 0; i < num_fences; ++i) { - struct dma_fence *next; - - while (fences[i] && dma_fence_is_signaled(fences[i])) - fences[i] = dma_fence_unwrap_next(&iter[i]); - - next = fences[i]; - if (!next) - continue; - - /* - * We can't guarantee that inpute fences are ordered by - * context, but it is still quite likely when this - * function is used multiple times. So attempt to order - * the fences by context as we pass over them and merge - * fences with the same context. - */ - if (!tmp || tmp->context > next->context) { - tmp = next; - sel = i; - - } else if (tmp->context < next->context) { - continue; - - } else if (dma_fence_is_later(tmp, next)) { - fences[i] = dma_fence_unwrap_next(&iter[i]); - goto restart; + for (i = 0; i < num_fences; ++i) { + dma_fence_unwrap_for_each(tmp, &iter[i], fences[i]) { + if (!dma_fence_is_signaled(tmp)) { + array[count++] = dma_fence_get(tmp); } else { - fences[sel] = dma_fence_unwrap_next(&iter[sel]); - goto restart; + ktime_t t = dma_fence_timestamp(tmp); + + if (ktime_after(t, timestamp)) + timestamp = t; } } + } - if (tmp) { - array[count++] = dma_fence_get(tmp); - fences[sel] = dma_fence_unwrap_next(&iter[sel]); - } - } while (tmp); + if (count == 0 || count == 1) + goto return_fastpath; - if (count == 0) { - tmp = dma_fence_allocate_private_stub(ktime_get()); - goto return_tmp; - } + sort(array, count, sizeof(*array), fence_cmp, NULL); - if (count == 1) { - tmp = array[0]; - goto return_tmp; + /* + * Only keep the most recent fence for each context. + */ + j = 0; + for (i = 1; i < count; i++) { + if (array[i]->context == array[j]->context) + dma_fence_put(array[i]); + else + array[++j] = array[i]; } + count = ++j; - result = dma_fence_array_create(count, array, - dma_fence_context_alloc(1), - 1, false); - if (!result) { - for (i = 0; i < count; i++) - dma_fence_put(array[i]); - tmp = NULL; - goto return_tmp; + if (count > 1) { + result = dma_fence_array_create(count, array, + dma_fence_context_alloc(1), + 1, false); + if (!result) { + for (i = 0; i < count; i++) + dma_fence_put(array[i]); + tmp = NULL; + goto return_tmp; + } + return &result->base; } - return &result->base; + +return_fastpath: + if (count == 0) + tmp = dma_fence_allocate_private_stub(timestamp); + else + tmp = array[0]; return_tmp: kfree(array);

1 week, 5 days

[PATCH 6.12 186/466] dma-fence: Fix reference leak on fence merge failure path

by Greg Kroah-Hartman

6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tvrtko Ursulin <tvrtko.ursulin(a)igalia.com> commit 949291c5314009b4f6e252391edbb40fdd5d5414 upstream. Release all fence references if the output dma-fence-array could not be allocated. Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin(a)igalia.com> Fixes: 245a4a7b531c ("dma-buf: generalize dma_fence unwrap & merging v3") Cc: Christian König <christian.koenig(a)amd.com> Cc: Daniel Vetter <daniel.vetter(a)ffwll.ch> Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: Gustavo Padovan <gustavo(a)padovan.org> Cc: Friedrich Vock <friedrich.vock(a)gmx.de> Cc: linux-media(a)vger.kernel.org Cc: dri-devel(a)lists.freedesktop.org Cc: linaro-mm-sig(a)lists.linaro.org Cc: <stable(a)vger.kernel.org> # v6.0+ Reviewed-by: Christian König <christian.koenig(a)amd.com> Signed-off-by: Christian König <christian.koenig(a)amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20241115102153.1980-2-tursuli… Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/dma-buf/dma-fence-unwrap.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/dma-buf/dma-fence-unwrap.c +++ b/drivers/dma-buf/dma-fence-unwrap.c @@ -164,6 +164,8 @@ restart: dma_fence_context_alloc(1), 1, false); if (!result) { + for (i = 0; i < count; i++) + dma_fence_put(array[i]); tmp = NULL; goto return_tmp; }

1 week, 5 days

Patch "dma-fence: Use kernel's sort for merging fences" has been added to the 6.12-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled dma-fence: Use kernel's sort for merging fences to the 6.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: dma-fence-use-kernel-s-sort-for-merging-fences.patch and it can be found in the queue-6.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. From fe52c649438b8489c9456681d93a9b3de3d38263 Mon Sep 17 00:00:00 2001 From: Tvrtko Ursulin <tvrtko.ursulin(a)igalia.com> Date: Fri, 15 Nov 2024 10:21:50 +0000 Subject: dma-fence: Use kernel's sort for merging fences MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Tvrtko Ursulin <tvrtko.ursulin(a)igalia.com> commit fe52c649438b8489c9456681d93a9b3de3d38263 upstream. One alternative to the fix Christian proposed in https://lore.kernel.org/dri-devel/20241024124159.4519-3-christian.koenig@am… is to replace the rather complex open coded sorting loops with the kernel standard sort followed by a context squashing pass. Proposed advantage of this would be readability but one concern Christian raised was that there could be many fences, that they are typically mostly sorted, and so the kernel's heap sort would be much worse by the proposed algorithm. I had a look running some games and vkcube to see what are the typical number of input fences. Tested scenarios: 1) Hogwarts Legacy under Gamescope 450 calls per second to __dma_fence_unwrap_merge. Percentages per number of fences buckets, before and after checking for signalled status, sorting and flattening: N Before After 0 0.91% 1 69.40% 2-3 28.72% 9.4% (90.6% resolved to one fence) 4-5 0.93% 6-9 0.03% 10+ 2) Cyberpunk 2077 under Gamescope 1050 calls per second, amounting to 0.01% CPU time according to perf top. N Before After 0 1.13% 1 52.30% 2-3 40.34% 55.57% 4-5 1.46% 0.50% 6-9 2.44% 10+ 2.34% 3) vkcube under Plasma 90 calls per second. N Before After 0 1 2-3 100% 0% (Ie. all resolved to a single fence) 4-5 6-9 10+ In the case of vkcube all invocations in the 2-3 bucket were actually just two input fences. From these numbers it looks like the heap sort should not be a disadvantage, given how the dominant case is <= 2 input fences which heap sort solves with just one compare and swap. (And for the case of one input fence we have a fast path in the previous patch.) A complementary possibility is to implement a different sorting algorithm under the same API as the kernel's sort() and so keep the simplicity, potentially moving the new sort under lib/ if it would be found more widely useful. v2: * Hold on to fence references and reduce commentary. (Christian) * Record and use latest signaled timestamp in the 2nd loop too. * Consolidate zero or one fences fast paths. v3: * Reverse the seqno sort order for a simpler squashing pass. (Christian) Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin(a)igalia.com> Fixes: 245a4a7b531c ("dma-buf: generalize dma_fence unwrap & merging v3") Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3617 Cc: Christian König <christian.koenig(a)amd.com> Cc: Daniel Vetter <daniel.vetter(a)ffwll.ch> Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: Gustavo Padovan <gustavo(a)padovan.org> Cc: Friedrich Vock <friedrich.vock(a)gmx.de> Cc: linux-media(a)vger.kernel.org Cc: dri-devel(a)lists.freedesktop.org Cc: linaro-mm-sig(a)lists.linaro.org Cc: <stable(a)vger.kernel.org> # v6.0+ Reviewed-by: Christian König <christian.koenig(a)amd.com> Signed-off-by: Christian König <christian.koenig(a)amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20241115102153.1980-3-tursuli… Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/dma-buf/dma-fence-unwrap.c | 126 +++++++++++++++++-------------------- 1 file changed, 60 insertions(+), 66 deletions(-) --- a/drivers/dma-buf/dma-fence-unwrap.c +++ b/drivers/dma-buf/dma-fence-unwrap.c @@ -12,6 +12,7 @@ #include <linux/dma-fence-chain.h> #include <linux/dma-fence-unwrap.h> #include <linux/slab.h> +#include <linux/sort.h> /* Internal helper to start new array iteration, don't use directly */ static struct dma_fence * @@ -59,6 +60,25 @@ struct dma_fence *dma_fence_unwrap_next( } EXPORT_SYMBOL_GPL(dma_fence_unwrap_next); + +static int fence_cmp(const void *_a, const void *_b) +{ + struct dma_fence *a = *(struct dma_fence **)_a; + struct dma_fence *b = *(struct dma_fence **)_b; + + if (a->context < b->context) + return -1; + else if (a->context > b->context) + return 1; + + if (dma_fence_is_later(b, a)) + return 1; + else if (dma_fence_is_later(a, b)) + return -1; + + return 0; +} + /* Implementation for the dma_fence_merge() marco, don't use directly */ struct dma_fence *__dma_fence_unwrap_merge(unsigned int num_fences, struct dma_fence **fences, @@ -67,8 +87,7 @@ struct dma_fence *__dma_fence_unwrap_mer struct dma_fence_array *result; struct dma_fence *tmp, **array; ktime_t timestamp; - unsigned int i; - size_t count; + int i, j, count; count = 0; timestamp = ns_to_ktime(0); @@ -96,80 +115,55 @@ struct dma_fence *__dma_fence_unwrap_mer if (!array) return NULL; - /* - * This trashes the input fence array and uses it as position for the - * following merge loop. This works because the dma_fence_merge() - * wrapper macro is creating this temporary array on the stack together - * with the iterators. - */ - for (i = 0; i < num_fences; ++i) - fences[i] = dma_fence_unwrap_first(fences[i], &iter[i]); - count = 0; - do { - unsigned int sel; - -restart: - tmp = NULL; - for (i = 0; i < num_fences; ++i) { - struct dma_fence *next; - - while (fences[i] && dma_fence_is_signaled(fences[i])) - fences[i] = dma_fence_unwrap_next(&iter[i]); - - next = fences[i]; - if (!next) - continue; - - /* - * We can't guarantee that inpute fences are ordered by - * context, but it is still quite likely when this - * function is used multiple times. So attempt to order - * the fences by context as we pass over them and merge - * fences with the same context. - */ - if (!tmp || tmp->context > next->context) { - tmp = next; - sel = i; - - } else if (tmp->context < next->context) { - continue; - - } else if (dma_fence_is_later(tmp, next)) { - fences[i] = dma_fence_unwrap_next(&iter[i]); - goto restart; + for (i = 0; i < num_fences; ++i) { + dma_fence_unwrap_for_each(tmp, &iter[i], fences[i]) { + if (!dma_fence_is_signaled(tmp)) { + array[count++] = dma_fence_get(tmp); } else { - fences[sel] = dma_fence_unwrap_next(&iter[sel]); - goto restart; + ktime_t t = dma_fence_timestamp(tmp); + + if (ktime_after(t, timestamp)) + timestamp = t; } } + } - if (tmp) { - array[count++] = dma_fence_get(tmp); - fences[sel] = dma_fence_unwrap_next(&iter[sel]); - } - } while (tmp); + if (count == 0 || count == 1) + goto return_fastpath; - if (count == 0) { - tmp = dma_fence_allocate_private_stub(ktime_get()); - goto return_tmp; - } + sort(array, count, sizeof(*array), fence_cmp, NULL); - if (count == 1) { - tmp = array[0]; - goto return_tmp; + /* + * Only keep the most recent fence for each context. + */ + j = 0; + for (i = 1; i < count; i++) { + if (array[i]->context == array[j]->context) + dma_fence_put(array[i]); + else + array[++j] = array[i]; } + count = ++j; - result = dma_fence_array_create(count, array, - dma_fence_context_alloc(1), - 1, false); - if (!result) { - for (i = 0; i < count; i++) - dma_fence_put(array[i]); - tmp = NULL; - goto return_tmp; + if (count > 1) { + result = dma_fence_array_create(count, array, + dma_fence_context_alloc(1), + 1, false); + if (!result) { + for (i = 0; i < count; i++) + dma_fence_put(array[i]); + tmp = NULL; + goto return_tmp; + } + return &result->base; } - return &result->base; + +return_fastpath: + if (count == 0) + tmp = dma_fence_allocate_private_stub(timestamp); + else + tmp = array[0]; return_tmp: kfree(array); Patches currently in stable-queue which might be from tvrtko.ursulin(a)igalia.com are queue-6.12/dma-fence-use-kernel-s-sort-for-merging-fences.patch queue-6.12/dma-buf-fix-dma_fence_array_signaled-v4.patch queue-6.12/dma-fence-fix-reference-leak-on-fence-merge-failure-path.patch

2 weeks

Patch "dma-fence: Fix reference leak on fence merge failure path" has been added to the 6.12-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled dma-fence: Fix reference leak on fence merge failure path to the 6.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: dma-fence-fix-reference-leak-on-fence-merge-failure-path.patch and it can be found in the queue-6.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. From 949291c5314009b4f6e252391edbb40fdd5d5414 Mon Sep 17 00:00:00 2001 From: Tvrtko Ursulin <tvrtko.ursulin(a)igalia.com> Date: Fri, 15 Nov 2024 10:21:49 +0000 Subject: dma-fence: Fix reference leak on fence merge failure path MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Tvrtko Ursulin <tvrtko.ursulin(a)igalia.com> commit 949291c5314009b4f6e252391edbb40fdd5d5414 upstream. Release all fence references if the output dma-fence-array could not be allocated. Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin(a)igalia.com> Fixes: 245a4a7b531c ("dma-buf: generalize dma_fence unwrap & merging v3") Cc: Christian König <christian.koenig(a)amd.com> Cc: Daniel Vetter <daniel.vetter(a)ffwll.ch> Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: Gustavo Padovan <gustavo(a)padovan.org> Cc: Friedrich Vock <friedrich.vock(a)gmx.de> Cc: linux-media(a)vger.kernel.org Cc: dri-devel(a)lists.freedesktop.org Cc: linaro-mm-sig(a)lists.linaro.org Cc: <stable(a)vger.kernel.org> # v6.0+ Reviewed-by: Christian König <christian.koenig(a)amd.com> Signed-off-by: Christian König <christian.koenig(a)amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20241115102153.1980-2-tursuli… Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/dma-buf/dma-fence-unwrap.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/dma-buf/dma-fence-unwrap.c +++ b/drivers/dma-buf/dma-fence-unwrap.c @@ -164,6 +164,8 @@ restart: dma_fence_context_alloc(1), 1, false); if (!result) { + for (i = 0; i < count; i++) + dma_fence_put(array[i]); tmp = NULL; goto return_tmp; } Patches currently in stable-queue which might be from tvrtko.ursulin(a)igalia.com are queue-6.12/dma-fence-use-kernel-s-sort-for-merging-fences.patch queue-6.12/dma-buf-fix-dma_fence_array_signaled-v4.patch queue-6.12/dma-fence-fix-reference-leak-on-fence-merge-failure-path.patch

2 weeks

Patch "dma-fence: Use kernel's sort for merging fences" has been added to the 6.6-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled dma-fence: Use kernel's sort for merging fences to the 6.6-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: dma-fence-use-kernel-s-sort-for-merging-fences.patch and it can be found in the queue-6.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. From fe52c649438b8489c9456681d93a9b3de3d38263 Mon Sep 17 00:00:00 2001 From: Tvrtko Ursulin <tvrtko.ursulin(a)igalia.com> Date: Fri, 15 Nov 2024 10:21:50 +0000 Subject: dma-fence: Use kernel's sort for merging fences MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Tvrtko Ursulin <tvrtko.ursulin(a)igalia.com> commit fe52c649438b8489c9456681d93a9b3de3d38263 upstream. One alternative to the fix Christian proposed in https://lore.kernel.org/dri-devel/20241024124159.4519-3-christian.koenig@am… is to replace the rather complex open coded sorting loops with the kernel standard sort followed by a context squashing pass. Proposed advantage of this would be readability but one concern Christian raised was that there could be many fences, that they are typically mostly sorted, and so the kernel's heap sort would be much worse by the proposed algorithm. I had a look running some games and vkcube to see what are the typical number of input fences. Tested scenarios: 1) Hogwarts Legacy under Gamescope 450 calls per second to __dma_fence_unwrap_merge. Percentages per number of fences buckets, before and after checking for signalled status, sorting and flattening: N Before After 0 0.91% 1 69.40% 2-3 28.72% 9.4% (90.6% resolved to one fence) 4-5 0.93% 6-9 0.03% 10+ 2) Cyberpunk 2077 under Gamescope 1050 calls per second, amounting to 0.01% CPU time according to perf top. N Before After 0 1.13% 1 52.30% 2-3 40.34% 55.57% 4-5 1.46% 0.50% 6-9 2.44% 10+ 2.34% 3) vkcube under Plasma 90 calls per second. N Before After 0 1 2-3 100% 0% (Ie. all resolved to a single fence) 4-5 6-9 10+ In the case of vkcube all invocations in the 2-3 bucket were actually just two input fences. From these numbers it looks like the heap sort should not be a disadvantage, given how the dominant case is <= 2 input fences which heap sort solves with just one compare and swap. (And for the case of one input fence we have a fast path in the previous patch.) A complementary possibility is to implement a different sorting algorithm under the same API as the kernel's sort() and so keep the simplicity, potentially moving the new sort under lib/ if it would be found more widely useful. v2: * Hold on to fence references and reduce commentary. (Christian) * Record and use latest signaled timestamp in the 2nd loop too. * Consolidate zero or one fences fast paths. v3: * Reverse the seqno sort order for a simpler squashing pass. (Christian) Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin(a)igalia.com> Fixes: 245a4a7b531c ("dma-buf: generalize dma_fence unwrap & merging v3") Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3617 Cc: Christian König <christian.koenig(a)amd.com> Cc: Daniel Vetter <daniel.vetter(a)ffwll.ch> Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: Gustavo Padovan <gustavo(a)padovan.org> Cc: Friedrich Vock <friedrich.vock(a)gmx.de> Cc: linux-media(a)vger.kernel.org Cc: dri-devel(a)lists.freedesktop.org Cc: linaro-mm-sig(a)lists.linaro.org Cc: <stable(a)vger.kernel.org> # v6.0+ Reviewed-by: Christian König <christian.koenig(a)amd.com> Signed-off-by: Christian König <christian.koenig(a)amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20241115102153.1980-3-tursuli… Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/dma-buf/dma-fence-unwrap.c | 126 +++++++++++++++++-------------------- 1 file changed, 60 insertions(+), 66 deletions(-) --- a/drivers/dma-buf/dma-fence-unwrap.c +++ b/drivers/dma-buf/dma-fence-unwrap.c @@ -12,6 +12,7 @@ #include <linux/dma-fence-chain.h> #include <linux/dma-fence-unwrap.h> #include <linux/slab.h> +#include <linux/sort.h> /* Internal helper to start new array iteration, don't use directly */ static struct dma_fence * @@ -59,6 +60,25 @@ struct dma_fence *dma_fence_unwrap_next( } EXPORT_SYMBOL_GPL(dma_fence_unwrap_next); + +static int fence_cmp(const void *_a, const void *_b) +{ + struct dma_fence *a = *(struct dma_fence **)_a; + struct dma_fence *b = *(struct dma_fence **)_b; + + if (a->context < b->context) + return -1; + else if (a->context > b->context) + return 1; + + if (dma_fence_is_later(b, a)) + return 1; + else if (dma_fence_is_later(a, b)) + return -1; + + return 0; +} + /* Implementation for the dma_fence_merge() marco, don't use directly */ struct dma_fence *__dma_fence_unwrap_merge(unsigned int num_fences, struct dma_fence **fences, @@ -67,8 +87,7 @@ struct dma_fence *__dma_fence_unwrap_mer struct dma_fence_array *result; struct dma_fence *tmp, **array; ktime_t timestamp; - unsigned int i; - size_t count; + int i, j, count; count = 0; timestamp = ns_to_ktime(0); @@ -96,80 +115,55 @@ struct dma_fence *__dma_fence_unwrap_mer if (!array) return NULL; - /* - * This trashes the input fence array and uses it as position for the - * following merge loop. This works because the dma_fence_merge() - * wrapper macro is creating this temporary array on the stack together - * with the iterators. - */ - for (i = 0; i < num_fences; ++i) - fences[i] = dma_fence_unwrap_first(fences[i], &iter[i]); - count = 0; - do { - unsigned int sel; - -restart: - tmp = NULL; - for (i = 0; i < num_fences; ++i) { - struct dma_fence *next; - - while (fences[i] && dma_fence_is_signaled(fences[i])) - fences[i] = dma_fence_unwrap_next(&iter[i]); - - next = fences[i]; - if (!next) - continue; - - /* - * We can't guarantee that inpute fences are ordered by - * context, but it is still quite likely when this - * function is used multiple times. So attempt to order - * the fences by context as we pass over them and merge - * fences with the same context. - */ - if (!tmp || tmp->context > next->context) { - tmp = next; - sel = i; - - } else if (tmp->context < next->context) { - continue; - - } else if (dma_fence_is_later(tmp, next)) { - fences[i] = dma_fence_unwrap_next(&iter[i]); - goto restart; + for (i = 0; i < num_fences; ++i) { + dma_fence_unwrap_for_each(tmp, &iter[i], fences[i]) { + if (!dma_fence_is_signaled(tmp)) { + array[count++] = dma_fence_get(tmp); } else { - fences[sel] = dma_fence_unwrap_next(&iter[sel]); - goto restart; + ktime_t t = dma_fence_timestamp(tmp); + + if (ktime_after(t, timestamp)) + timestamp = t; } } + } - if (tmp) { - array[count++] = dma_fence_get(tmp); - fences[sel] = dma_fence_unwrap_next(&iter[sel]); - } - } while (tmp); + if (count == 0 || count == 1) + goto return_fastpath; - if (count == 0) { - tmp = dma_fence_allocate_private_stub(ktime_get()); - goto return_tmp; - } + sort(array, count, sizeof(*array), fence_cmp, NULL); - if (count == 1) { - tmp = array[0]; - goto return_tmp; + /* + * Only keep the most recent fence for each context. + */ + j = 0; + for (i = 1; i < count; i++) { + if (array[i]->context == array[j]->context) + dma_fence_put(array[i]); + else + array[++j] = array[i]; } + count = ++j; - result = dma_fence_array_create(count, array, - dma_fence_context_alloc(1), - 1, false); - if (!result) { - for (i = 0; i < count; i++) - dma_fence_put(array[i]); - tmp = NULL; - goto return_tmp; + if (count > 1) { + result = dma_fence_array_create(count, array, + dma_fence_context_alloc(1), + 1, false); + if (!result) { + for (i = 0; i < count; i++) + dma_fence_put(array[i]); + tmp = NULL; + goto return_tmp; + } + return &result->base; } - return &result->base; + +return_fastpath: + if (count == 0) + tmp = dma_fence_allocate_private_stub(timestamp); + else + tmp = array[0]; return_tmp: kfree(array); Patches currently in stable-queue which might be from tvrtko.ursulin(a)igalia.com are queue-6.6/dma-fence-use-kernel-s-sort-for-merging-fences.patch queue-6.6/dma-buf-fix-dma_fence_array_signaled-v4.patch queue-6.6/dma-fence-fix-reference-leak-on-fence-merge-failure-path.patch

2 weeks

Patch "dma-fence: Fix reference leak on fence merge failure path" has been added to the 6.6-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled dma-fence: Fix reference leak on fence merge failure path to the 6.6-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: dma-fence-fix-reference-leak-on-fence-merge-failure-path.patch and it can be found in the queue-6.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. From 949291c5314009b4f6e252391edbb40fdd5d5414 Mon Sep 17 00:00:00 2001 From: Tvrtko Ursulin <tvrtko.ursulin(a)igalia.com> Date: Fri, 15 Nov 2024 10:21:49 +0000 Subject: dma-fence: Fix reference leak on fence merge failure path MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Tvrtko Ursulin <tvrtko.ursulin(a)igalia.com> commit 949291c5314009b4f6e252391edbb40fdd5d5414 upstream. Release all fence references if the output dma-fence-array could not be allocated. Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin(a)igalia.com> Fixes: 245a4a7b531c ("dma-buf: generalize dma_fence unwrap & merging v3") Cc: Christian König <christian.koenig(a)amd.com> Cc: Daniel Vetter <daniel.vetter(a)ffwll.ch> Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: Gustavo Padovan <gustavo(a)padovan.org> Cc: Friedrich Vock <friedrich.vock(a)gmx.de> Cc: linux-media(a)vger.kernel.org Cc: dri-devel(a)lists.freedesktop.org Cc: linaro-mm-sig(a)lists.linaro.org Cc: <stable(a)vger.kernel.org> # v6.0+ Reviewed-by: Christian König <christian.koenig(a)amd.com> Signed-off-by: Christian König <christian.koenig(a)amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20241115102153.1980-2-tursuli… Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/dma-buf/dma-fence-unwrap.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/dma-buf/dma-fence-unwrap.c +++ b/drivers/dma-buf/dma-fence-unwrap.c @@ -164,6 +164,8 @@ restart: dma_fence_context_alloc(1), 1, false); if (!result) { + for (i = 0; i < count; i++) + dma_fence_put(array[i]); tmp = NULL; goto return_tmp; } Patches currently in stable-queue which might be from tvrtko.ursulin(a)igalia.com are queue-6.6/dma-fence-use-kernel-s-sort-for-merging-fences.patch queue-6.6/dma-buf-fix-dma_fence_array_signaled-v4.patch queue-6.6/dma-fence-fix-reference-leak-on-fence-merge-failure-path.patch

2 weeks

Patch "dma-fence: Use kernel's sort for merging fences" has been added to the 6.1-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled dma-fence: Use kernel's sort for merging fences to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: dma-fence-use-kernel-s-sort-for-merging-fences.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. From fe52c649438b8489c9456681d93a9b3de3d38263 Mon Sep 17 00:00:00 2001 From: Tvrtko Ursulin <tvrtko.ursulin(a)igalia.com> Date: Fri, 15 Nov 2024 10:21:50 +0000 Subject: dma-fence: Use kernel's sort for merging fences MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Tvrtko Ursulin <tvrtko.ursulin(a)igalia.com> commit fe52c649438b8489c9456681d93a9b3de3d38263 upstream. One alternative to the fix Christian proposed in https://lore.kernel.org/dri-devel/20241024124159.4519-3-christian.koenig@am… is to replace the rather complex open coded sorting loops with the kernel standard sort followed by a context squashing pass. Proposed advantage of this would be readability but one concern Christian raised was that there could be many fences, that they are typically mostly sorted, and so the kernel's heap sort would be much worse by the proposed algorithm. I had a look running some games and vkcube to see what are the typical number of input fences. Tested scenarios: 1) Hogwarts Legacy under Gamescope 450 calls per second to __dma_fence_unwrap_merge. Percentages per number of fences buckets, before and after checking for signalled status, sorting and flattening: N Before After 0 0.91% 1 69.40% 2-3 28.72% 9.4% (90.6% resolved to one fence) 4-5 0.93% 6-9 0.03% 10+ 2) Cyberpunk 2077 under Gamescope 1050 calls per second, amounting to 0.01% CPU time according to perf top. N Before After 0 1.13% 1 52.30% 2-3 40.34% 55.57% 4-5 1.46% 0.50% 6-9 2.44% 10+ 2.34% 3) vkcube under Plasma 90 calls per second. N Before After 0 1 2-3 100% 0% (Ie. all resolved to a single fence) 4-5 6-9 10+ In the case of vkcube all invocations in the 2-3 bucket were actually just two input fences. From these numbers it looks like the heap sort should not be a disadvantage, given how the dominant case is <= 2 input fences which heap sort solves with just one compare and swap. (And for the case of one input fence we have a fast path in the previous patch.) A complementary possibility is to implement a different sorting algorithm under the same API as the kernel's sort() and so keep the simplicity, potentially moving the new sort under lib/ if it would be found more widely useful. v2: * Hold on to fence references and reduce commentary. (Christian) * Record and use latest signaled timestamp in the 2nd loop too. * Consolidate zero or one fences fast paths. v3: * Reverse the seqno sort order for a simpler squashing pass. (Christian) Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin(a)igalia.com> Fixes: 245a4a7b531c ("dma-buf: generalize dma_fence unwrap & merging v3") Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3617 Cc: Christian König <christian.koenig(a)amd.com> Cc: Daniel Vetter <daniel.vetter(a)ffwll.ch> Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: Gustavo Padovan <gustavo(a)padovan.org> Cc: Friedrich Vock <friedrich.vock(a)gmx.de> Cc: linux-media(a)vger.kernel.org Cc: dri-devel(a)lists.freedesktop.org Cc: linaro-mm-sig(a)lists.linaro.org Cc: <stable(a)vger.kernel.org> # v6.0+ Reviewed-by: Christian König <christian.koenig(a)amd.com> Signed-off-by: Christian König <christian.koenig(a)amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20241115102153.1980-3-tursuli… Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/dma-buf/dma-fence-unwrap.c | 128 ++++++++++++++--------------- 1 file changed, 61 insertions(+), 67 deletions(-) diff --git a/drivers/dma-buf/dma-fence-unwrap.c b/drivers/dma-buf/dma-fence-unwrap.c index b19d0adf6086..6345062731f1 100644 --- a/drivers/dma-buf/dma-fence-unwrap.c +++ b/drivers/dma-buf/dma-fence-unwrap.c @@ -12,6 +12,7 @@ #include <linux/dma-fence-chain.h> #include <linux/dma-fence-unwrap.h> #include <linux/slab.h> +#include <linux/sort.h> /* Internal helper to start new array iteration, don't use directly */ static struct dma_fence * @@ -59,6 +60,25 @@ struct dma_fence *dma_fence_unwrap_next(struct dma_fence_unwrap *cursor) } EXPORT_SYMBOL_GPL(dma_fence_unwrap_next); + +static int fence_cmp(const void *_a, const void *_b) +{ + struct dma_fence *a = *(struct dma_fence **)_a; + struct dma_fence *b = *(struct dma_fence **)_b; + + if (a->context < b->context) + return -1; + else if (a->context > b->context) + return 1; + + if (dma_fence_is_later(b, a)) + return 1; + else if (dma_fence_is_later(a, b)) + return -1; + + return 0; +} + /* Implementation for the dma_fence_merge() marco, don't use directly */ struct dma_fence *__dma_fence_unwrap_merge(unsigned int num_fences, struct dma_fence **fences, @@ -67,8 +87,7 @@ struct dma_fence *__dma_fence_unwrap_merge(unsigned int num_fences, struct dma_fence_array *result; struct dma_fence *tmp, **array; ktime_t timestamp; - unsigned int i; - size_t count; + int i, j, count; count = 0; timestamp = ns_to_ktime(0); @@ -96,80 +115,55 @@ struct dma_fence *__dma_fence_unwrap_merge(unsigned int num_fences, if (!array) return NULL; - /* - * This trashes the input fence array and uses it as position for the - * following merge loop. This works because the dma_fence_merge() - * wrapper macro is creating this temporary array on the stack together - * with the iterators. - */ - for (i = 0; i < num_fences; ++i) - fences[i] = dma_fence_unwrap_first(fences[i], &iter[i]); - count = 0; - do { - unsigned int sel; - -restart: - tmp = NULL; - for (i = 0; i < num_fences; ++i) { - struct dma_fence *next; - - while (fences[i] && dma_fence_is_signaled(fences[i])) - fences[i] = dma_fence_unwrap_next(&iter[i]); - - next = fences[i]; - if (!next) - continue; - - /* - * We can't guarantee that inpute fences are ordered by - * context, but it is still quite likely when this - * function is used multiple times. So attempt to order - * the fences by context as we pass over them and merge - * fences with the same context. - */ - if (!tmp || tmp->context > next->context) { - tmp = next; - sel = i; - - } else if (tmp->context < next->context) { - continue; - - } else if (dma_fence_is_later(tmp, next)) { - fences[i] = dma_fence_unwrap_next(&iter[i]); - goto restart; + for (i = 0; i < num_fences; ++i) { + dma_fence_unwrap_for_each(tmp, &iter[i], fences[i]) { + if (!dma_fence_is_signaled(tmp)) { + array[count++] = dma_fence_get(tmp); } else { - fences[sel] = dma_fence_unwrap_next(&iter[sel]); - goto restart; + ktime_t t = dma_fence_timestamp(tmp); + + if (ktime_after(t, timestamp)) + timestamp = t; } } - - if (tmp) { - array[count++] = dma_fence_get(tmp); - fences[sel] = dma_fence_unwrap_next(&iter[sel]); - } - } while (tmp); - - if (count == 0) { - tmp = dma_fence_allocate_private_stub(ktime_get()); - goto return_tmp; } - if (count == 1) { - tmp = array[0]; - goto return_tmp; - } + if (count == 0 || count == 1) + goto return_fastpath; - result = dma_fence_array_create(count, array, - dma_fence_context_alloc(1), - 1, false); - if (!result) { - for (i = 0; i < count; i++) + sort(array, count, sizeof(*array), fence_cmp, NULL); + + /* + * Only keep the most recent fence for each context. + */ + j = 0; + for (i = 1; i < count; i++) { + if (array[i]->context == array[j]->context) dma_fence_put(array[i]); - tmp = NULL; - goto return_tmp; + else + array[++j] = array[i]; } - return &result->base; + count = ++j; + + if (count > 1) { + result = dma_fence_array_create(count, array, + dma_fence_context_alloc(1), + 1, false); + if (!result) { + for (i = 0; i < count; i++) + dma_fence_put(array[i]); + tmp = NULL; + goto return_tmp; + } + return &result->base; + } + +return_fastpath: + if (count == 0) + tmp = dma_fence_allocate_private_stub(timestamp); + else + tmp = array[0]; return_tmp: kfree(array); -- 2.47.1 Patches currently in stable-queue which might be from tvrtko.ursulin(a)igalia.com are queue-6.1/dma-fence-use-kernel-s-sort-for-merging-fences.patch queue-6.1/dma-buf-fix-dma_fence_array_signaled-v4.patch queue-6.1/dma-fence-fix-reference-leak-on-fence-merge-failure-path.patch

2 weeks

Patch "dma-fence: Fix reference leak on fence merge failure path" has been added to the 6.1-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled dma-fence: Fix reference leak on fence merge failure path to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: dma-fence-fix-reference-leak-on-fence-merge-failure-path.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. From 949291c5314009b4f6e252391edbb40fdd5d5414 Mon Sep 17 00:00:00 2001 From: Tvrtko Ursulin <tvrtko.ursulin(a)igalia.com> Date: Fri, 15 Nov 2024 10:21:49 +0000 Subject: dma-fence: Fix reference leak on fence merge failure path MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Tvrtko Ursulin <tvrtko.ursulin(a)igalia.com> commit 949291c5314009b4f6e252391edbb40fdd5d5414 upstream. Release all fence references if the output dma-fence-array could not be allocated. Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin(a)igalia.com> Fixes: 245a4a7b531c ("dma-buf: generalize dma_fence unwrap & merging v3") Cc: Christian König <christian.koenig(a)amd.com> Cc: Daniel Vetter <daniel.vetter(a)ffwll.ch> Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: Gustavo Padovan <gustavo(a)padovan.org> Cc: Friedrich Vock <friedrich.vock(a)gmx.de> Cc: linux-media(a)vger.kernel.org Cc: dri-devel(a)lists.freedesktop.org Cc: linaro-mm-sig(a)lists.linaro.org Cc: <stable(a)vger.kernel.org> # v6.0+ Reviewed-by: Christian König <christian.koenig(a)amd.com> Signed-off-by: Christian König <christian.koenig(a)amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20241115102153.1980-2-tursuli… Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/dma-buf/dma-fence-unwrap.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/dma-buf/dma-fence-unwrap.c b/drivers/dma-buf/dma-fence-unwrap.c index 628af51c81af..b19d0adf6086 100644 --- a/drivers/dma-buf/dma-fence-unwrap.c +++ b/drivers/dma-buf/dma-fence-unwrap.c @@ -164,6 +164,8 @@ struct dma_fence *__dma_fence_unwrap_merge(unsigned int num_fences, dma_fence_context_alloc(1), 1, false); if (!result) { + for (i = 0; i < count; i++) + dma_fence_put(array[i]); tmp = NULL; goto return_tmp; } -- 2.47.1 Patches currently in stable-queue which might be from tvrtko.ursulin(a)igalia.com are queue-6.1/dma-fence-use-kernel-s-sort-for-merging-fences.patch queue-6.1/dma-buf-fix-dma_fence_array_signaled-v4.patch queue-6.1/dma-fence-fix-reference-leak-on-fence-merge-failure-path.patch

2 weeks

[RFC 00/24] drm/msm: sparse / "VM_BIND" support

by Rob Clark

From: Rob Clark <robdclark(a)chromium.org> Conversion to DRM GPU VA Manager[1], and adding support for Vulkan Sparse Memory[2] in the form of: 1. A new VM_BIND submitqueue type for executing VM MSM_SUBMIT_BO_OP_MAP/ MAP_NULL/UNMAP commands 2. Extending the SUBMIT` ioctl to allow submitting batches of one or more MAP/MAP_NULL/UNMAP commands to a VM_BIND submitqueue The UABI takes a slightly different approach from what other drivers have done, and what would make sense if starting from a clean sheet, ie separate VM_BIND and EXEC ioctls. But since we have to maintain support for the existing SUBMIT ioctl, and because the fence, syncobj, and BO pinning is largely the same between legacy "BO-table" style SUBMIT ioctls, and new- style VM updates submitted to a VM_BIND submitqueue, I chose to go the route of extending the existing `SUBMIT` ioctl rather than adding a new ioctl. I also did not implement support for synchronous VM_BIND commands. Since userspace could just immediately wait for the `SUBMIT` to complete, I don't think we need this extra complexity in the kernel. The corresponding mesa MR: https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/32533 ### Notes/TODOs/Open Questions: 1. The first handful of patches are from Bibek Kumar Patro's series, "iommu/arm-smmu: introduction of ACTLR implementation for Qualcomm SoCs[3], which introduces PRR (Partially-Resident-Region) support, needed to implement MAP_NULL (for Vulkan Sparse Residency[4] 2. Why do VM_BIND commands need fence fd support, instead of just syncobjs? Mainly for the benefit of virtgpu drm native context guest<->host fence passing[5], where the host VMM is operating in terms of fence fd's (syncobs are just a convenience wrapper above a dma_fence, and don't exist below the guest kernel). 3. Currently shrinker support is disabled (hence this being in Draft/RFC state). To properly support the shrinker, we need to pre-allocate various objects and pages needed for the pagetables themselves, to move memory allocations out of the fence signaling path. This short- cut was taken to unblock userspace implementation of sparse buffer/ image support. 4. Could/should we do all the vm/vma updates synchronously and defer _only_ the io-pgtable updates to the VM_BIND scheduler queue? This would simplify the previous point, in that we'd only have to pre-allocate pages for the io-pgtable updates. 5. Currently we lose support for BO dumping for devcoredump. Ideally we'd plumb `MSM_SUBMIT_BO_DUMP` flag in a `MAP` commands thru to the resulting drm_gpuva's. To do this, I think we need to extend drm_gpuva with a flags field.. the flags can be driver defined, but drm_gpuvm needs to know not to merge drm_gpuva's with different flags. This series can be found in MR form, if you prefer: https://gitlab.freedesktop.org/drm/msm/-/merge_requests/144 [1] https://www.kernel.org/doc/html/next/gpu/drm-mm.html#drm-gpuvm [2] https://docs.vulkan.org/spec/latest/chapters/sparsemem.html [3] https://patchwork.kernel.org/project/linux-arm-kernel/list/?series=909700 [4] https://docs.vulkan.org/spec/latest/chapters/sparsemem.html#sparsememory-pa… [5] https://patchew.org/linux/20231007194747.788934-1-dmitry.osipenko@collabora… Rob Clark (24): HACK: drm/msm: Disable shrinker drm/gpuvm: Don't require obj lock in destructor path drm/gpuvm: Remove bogus lock assert drm/msm: Rename msm_file_private -> msm_context drm/msm: Improve msm_context comments drm/msm: Rename msm_gem_address_space -> msm_gem_vm drm/msm: Remove vram carveout support drm/msm: Collapse vma allocation and initialization drm/msm: Collapse vma close and delete drm/msm: drm_gpuvm conversion drm/msm: Use drm_gpuvm types more drm/msm: Split submit_pin_objects() drm/msm: Lazily create context VM drm/msm: Add opt-in for VM_BIND drm/msm: Mark VM as unusable on faults drm/msm: Extend SUBMIT ioctl for VM_BIND drm/msm: Add VM_BIND submitqueue drm/msm: Add _NO_SHARE flag drm/msm: Split out helper to get iommu prot flags drm/msm: Add mmu support for non-zero offset drm/msm: Add PRR support drm/msm: Rename msm_gem_vma_purge() -> _unmap() drm/msm: Wire up gpuvm ops drm/msm: Bump UAPI version drivers/gpu/drm/drm_gpuvm.c | 10 +- drivers/gpu/drm/msm/Kconfig | 1 + drivers/gpu/drm/msm/adreno/a2xx_gpu.c | 19 +- drivers/gpu/drm/msm/adreno/a2xx_gpummu.c | 5 +- drivers/gpu/drm/msm/adreno/a3xx_gpu.c | 4 +- drivers/gpu/drm/msm/adreno/a4xx_gpu.c | 4 +- drivers/gpu/drm/msm/adreno/a5xx_debugfs.c | 4 +- drivers/gpu/drm/msm/adreno/a5xx_gpu.c | 24 +- drivers/gpu/drm/msm/adreno/a5xx_power.c | 2 +- drivers/gpu/drm/msm/adreno/a5xx_preempt.c | 10 +- drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 32 +- drivers/gpu/drm/msm/adreno/a6xx_gmu.h | 2 +- drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 51 +- drivers/gpu/drm/msm/adreno/a6xx_gpu_state.c | 6 +- drivers/gpu/drm/msm/adreno/a6xx_preempt.c | 10 +- drivers/gpu/drm/msm/adreno/adreno_gpu.c | 78 ++- drivers/gpu/drm/msm/adreno/adreno_gpu.h | 22 +- .../drm/msm/disp/dpu1/dpu_encoder_phys_wb.c | 14 +- drivers/gpu/drm/msm/disp/dpu1/dpu_formats.c | 18 +- drivers/gpu/drm/msm/disp/dpu1/dpu_formats.h | 2 +- drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c | 18 +- drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c | 14 +- drivers/gpu/drm/msm/disp/dpu1/dpu_plane.h | 4 +- drivers/gpu/drm/msm/disp/mdp4/mdp4_crtc.c | 6 +- drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c | 28 +- drivers/gpu/drm/msm/disp/mdp4/mdp4_plane.c | 12 +- drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c | 4 +- drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c | 19 +- drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c | 12 +- drivers/gpu/drm/msm/dsi/dsi_host.c | 14 +- drivers/gpu/drm/msm/msm_drv.c | 175 ++---- drivers/gpu/drm/msm/msm_drv.h | 31 +- drivers/gpu/drm/msm/msm_fb.c | 18 +- drivers/gpu/drm/msm/msm_fbdev.c | 2 +- drivers/gpu/drm/msm/msm_gem.c | 403 ++++++------- drivers/gpu/drm/msm/msm_gem.h | 193 +++++-- drivers/gpu/drm/msm/msm_gem_prime.c | 15 + drivers/gpu/drm/msm/msm_gem_submit.c | 223 +++++-- drivers/gpu/drm/msm/msm_gem_vma.c | 543 +++++++++++++++--- drivers/gpu/drm/msm/msm_gpu.c | 66 ++- drivers/gpu/drm/msm/msm_gpu.h | 132 +++-- drivers/gpu/drm/msm/msm_iommu.c | 84 ++- drivers/gpu/drm/msm/msm_kms.c | 14 +- drivers/gpu/drm/msm/msm_kms.h | 2 +- drivers/gpu/drm/msm/msm_mmu.h | 2 +- drivers/gpu/drm/msm/msm_ringbuffer.c | 4 +- drivers/gpu/drm/msm/msm_submitqueue.c | 86 ++- include/uapi/drm/msm_drm.h | 98 +++- 48 files changed, 1637 insertions(+), 903 deletions(-) -- 2.47.1

2 weeks, 3 days

[PATCH v2] Documentation: dma-buf: heaps: Add heap name definitions

by Maxime Ripard

Following a recent discussion at last Plumbers, John Stultz, Sumit Sewal, TJ Mercier and I came to an agreement that we should document what the dma-buf heaps names are expected to be, and what the buffers attributes you'll get should be documented. Let's create that doc to make sure those attributes and names are guaranteed going forward. Signed-off-by: Maxime Ripard <mripard(a)kernel.org> --- Changes from v1: - Add the mention that the cma / reserved heap is optional. To: Jonathan Corbet <corbet(a)lwn.net> To: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: Benjamin Gaignard <benjamin.gaignard(a)collabora.com> Cc: Brian Starkey <Brian.Starkey(a)arm.com> Cc: John Stultz <jstultz(a)google.com> Cc: "T.J. Mercier" <tjmercier(a)google.com> Cc: "Christian König" <christian.koenig(a)amd.com> Cc: dri-devel(a)lists.freedesktop.org Cc: linaro-mm-sig(a)lists.linaro.org Cc: linux-media(a)vger.kernel.org Cc: linux-doc(a)vger.kernel.org --- Documentation/userspace-api/dma-buf-heaps.rst | 76 +++++++++++++++++++ Documentation/userspace-api/index.rst | 1 + 2 files changed, 77 insertions(+) create mode 100644 Documentation/userspace-api/dma-buf-heaps.rst diff --git a/Documentation/userspace-api/dma-buf-heaps.rst b/Documentation/userspace-api/dma-buf-heaps.rst new file mode 100644 index 000000000000..68be7ddea150 --- /dev/null +++ b/Documentation/userspace-api/dma-buf-heaps.rst @@ -0,0 +1,76 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============================== +Allocating dma-buf using heaps +============================== + +Dma-buf Heaps are a way for userspace to allocate dma-buf objects. They are +typically used to allocate buffers from a specific allocation pool, or to share +buffers across frameworks. + +Heaps +===== + +A heap represent a specific allocator. The Linux kernel currently supports the +following heaps: + + - The ``system`` heap allocates virtually contiguous, cacheable, buffers + + - The ``reserved`` heap allocates physically contiguous, cacheable, + buffers. Only present if a CMA region is present. Such a region is + usually created either through the kernel commandline through the + `cma` parameter, a memory region Device-Tree node with the + `linux,cma-default` property set, or through the `CMA_SIZE_MBYTES` or + `CMA_SIZE_PERCENTAGE` Kconfig options. Depending on the platform, it + might be called differently: + + - Acer Iconia Tab A500: ``linux,cma`` + - Allwinner sun4i, sun5i and sun7i families: ``default-pool`` + - Amlogic A1: ``linux,cma`` + - Amlogic G12A/G12B/SM1: ``linux,cma`` + - Amlogic GXBB/GXL: ``linux,cma`` + - ASUS EeePad Transformer TF101: ``linux,cma`` + - ASUS Google Nexus 7 (Project Bach / ME370TG) E1565: ``linux,cma`` + - ASUS Google Nexus 7 (Project Nakasi / ME370T) E1565: ``linux,cma`` + - ASUS Google Nexus 7 (Project Nakasi / ME370T) PM269: ``linux,cma`` + - Asus Transformer Infinity TF700T: ``linux,cma`` + - Asus Transformer Pad 3G TF300TG: ``linux,cma`` + - Asus Transformer Pad TF300T: ``linux,cma`` + - Asus Transformer Pad TF701T: ``linux,cma`` + - Asus Transformer Prime TF201: ``linux,cma`` + - ASUS Vivobook S 15: ``linux,cma`` + - Cadence KC705: ``linux,cma`` + - Digi International ConnectCore 6UL: ``linux,cma`` + - Freescale i.MX8DXL EVK: ``linux,cma`` + - Freescale TQMa8Xx: ``linux,cma`` + - Hisilicon Hikey: ``linux,cma`` + - Lenovo ThinkPad T14s Gen 6: ``linux,cma`` + - Lenovo ThinkPad X13s: ``linux,cma`` + - Lenovo Yoga Slim 7x: ``linux,cma`` + - LG Optimus 4X HD P880: ``linux,cma`` + - LG Optimus Vu P895: ``linux,cma`` + - Loongson 2k0500, 2k1000 and 2k2000: ``linux,cma`` + - Microsoft Romulus: ``linux,cma`` + - NXP i.MX8ULP EVK: ``linux,cma`` + - NXP i.MX93 9x9 QSB: ``linux,cma`` + - NXP i.MX93 11X11 EVK: ``linux,cma`` + - NXP i.MX93 14X14 EVK: ``linux,cma`` + - NXP i.MX95 19X19 EVK: ``linux,cma`` + - Ouya Game Console: ``linux,cma`` + - Pegatron Chagall: ``linux,cma`` + - PHYTEC phyCORE-AM62A SOM: ``linux,cma`` + - PHYTEC phyCORE-i.MX93 SOM: ``linux,cma`` + - Qualcomm SC8280XP CRD: ``linux,cma`` + - Qualcomm X1E80100 CRD: ``linux,cma`` + - Qualcomm X1E80100 QCP: ``linux,cma`` + - RaspberryPi: ``linux,cma`` + - Texas Instruments AM62x SK board family: ``linux,cma`` + - Texas Instruments AM62A7 SK: ``linux,cma`` + - Toradex Apalis iMX8: ``linux,cma`` + - TQ-Systems i.MX8MM TQMa8MxML: ``linux,cma`` + - TQ-Systems i.MX8MN TQMa8MxNL: ``linux,cma`` + - TQ-Systems i.MX8MPlus TQMa8MPxL: ``linux,cma`` + - TQ-Systems i.MX8MQ TQMa8MQ: ``linux,cma`` + - TQ-Systems i.MX93 TQMa93xxLA/TQMa93xxCA SOM: ``linux,cma`` + - TQ-Systems MBA6ULx Baseboard: ``linux,cma`` + diff --git a/Documentation/userspace-api/index.rst b/Documentation/userspace-api/index.rst index 274cc7546efc..4901ce7c6cb7 100644 --- a/Documentation/userspace-api/index.rst +++ b/Documentation/userspace-api/index.rst @@ -41,10 +41,11 @@ Devices and I/O .. toctree:: :maxdepth: 1 accelerators/ocxl + dma-buf-heaps dma-buf-alloc-exchange gpio/index iommufd media/index dcdbas -- 2.47.1

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Linaro-mm-sig December 2024