* [PATCH 5.15.y 0/2] fix issue in damon_va_evenly_split_region() [not found] <2024120625-recycling-till-0cca@gregkh> @ 2024-12-06 18:16 ` SeongJae Park 2024-12-06 18:16 ` [PATCH 5.15.y 1/2] mm/damon/vaddr-test: split a test function having >1024 bytes frame size SeongJae Park 2024-12-06 18:16 ` [PATCH 5.15.y 2/2] mm/damon/vaddr: fix issue in damon_va_evenly_split_region() SeongJae Park 0 siblings, 2 replies; 4+ messages in thread From: SeongJae Park @ 2024-12-06 18:16 UTC (permalink / raw) To: stable; +Cc: SeongJae Park, damon, linux-mm The fix depends on 044cd9750fe0 ("mm/damon/vaddr-test: split a test function having >1024 bytes frame size"), which is not on 5.15.y tree. Even after applying it, the fix might not cleanly cherry-picked due to the file path change that seems not automatically detected on every setup[1]. Since my setup somehow automatically detects the file path change and do cherry-pick cleanly, posting both patches to avoid unnecessary delay. [1] https://lore.kernel.org/20241206173426.75223-1-sj@kernel.org SeongJae Park (1): mm/damon/vaddr-test: split a test function having >1024 bytes frame size Zheng Yejian (1): mm/damon/vaddr: fix issue in damon_va_evenly_split_region() mm/damon/vaddr-test.h | 78 +++++++++++++++++++++++-------------------- mm/damon/vaddr.c | 4 +-- 2 files changed, 43 insertions(+), 39 deletions(-) -- 2.39.5 ^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH 5.15.y 1/2] mm/damon/vaddr-test: split a test function having >1024 bytes frame size 2024-12-06 18:16 ` [PATCH 5.15.y 0/2] fix issue in damon_va_evenly_split_region() SeongJae Park @ 2024-12-06 18:16 ` SeongJae Park 2024-12-06 20:30 ` David Laight 2024-12-06 18:16 ` [PATCH 5.15.y 2/2] mm/damon/vaddr: fix issue in damon_va_evenly_split_region() SeongJae Park 1 sibling, 1 reply; 4+ messages in thread From: SeongJae Park @ 2024-12-06 18:16 UTC (permalink / raw) To: stable Cc: SeongJae Park, damon, linux-mm, kernel test robot, Brendan Higgins, Shuah Khan, Andrew Morton, Linus Torvalds On some configuration[1], 'damon_test_split_evenly()' kunit test function has >1024 bytes frame size, so below build warning is triggered: CC mm/damon/vaddr.o In file included from mm/damon/vaddr.c:672: mm/damon/vaddr-test.h: In function 'damon_test_split_evenly': mm/damon/vaddr-test.h:309:1: warning: the frame size of 1064 bytes is larger than 1024 bytes [-Wframe-larger-than=] 309 | } | ^ This commit fixes the warning by separating the common logic in the function. [1] https://lore.kernel.org/linux-mm/202111182146.OV3C4uGr-lkp@intel.com/ Link: https://lkml.kernel.org/r/20211201150440.1088-6-sj@kernel.org Fixes: 17ccae8bb5c9 ("mm/damon: add kunit tests") Signed-off-by: SeongJae Park <sj@kernel.org> Reported-by: kernel test robot <lkp@intel.com> Cc: Brendan Higgins <brendanhiggins@google.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> (cherry picked from commit 044cd9750fe010170f5dc812e4824d98f5ea928c) --- mm/damon/vaddr-test.h | 77 ++++++++++++++++++++++--------------------- 1 file changed, 40 insertions(+), 37 deletions(-) diff --git a/mm/damon/vaddr-test.h b/mm/damon/vaddr-test.h index 1f5c13257dba..95ec362cdc37 100644 --- a/mm/damon/vaddr-test.h +++ b/mm/damon/vaddr-test.h @@ -252,59 +252,62 @@ static void damon_test_apply_three_regions4(struct kunit *test) new_three_regions, expected, ARRAY_SIZE(expected)); } -static void damon_test_split_evenly(struct kunit *test) +static void damon_test_split_evenly_fail(struct kunit *test, + unsigned long start, unsigned long end, unsigned int nr_pieces) { - struct damon_ctx *c = damon_new_ctx(); - struct damon_target *t; - struct damon_region *r; - unsigned long i; - - KUNIT_EXPECT_EQ(test, damon_va_evenly_split_region(NULL, NULL, 5), - -EINVAL); - - t = damon_new_target(42); - r = damon_new_region(0, 100); - KUNIT_EXPECT_EQ(test, damon_va_evenly_split_region(t, r, 0), -EINVAL); + struct damon_target *t = damon_new_target(42); + struct damon_region *r = damon_new_region(start, end); damon_add_region(r, t); - KUNIT_EXPECT_EQ(test, damon_va_evenly_split_region(t, r, 10), 0); - KUNIT_EXPECT_EQ(test, damon_nr_regions(t), 10u); + KUNIT_EXPECT_EQ(test, + damon_va_evenly_split_region(t, r, nr_pieces), -EINVAL); + KUNIT_EXPECT_EQ(test, damon_nr_regions(t), 1u); - i = 0; damon_for_each_region(r, t) { - KUNIT_EXPECT_EQ(test, r->ar.start, i++ * 10); - KUNIT_EXPECT_EQ(test, r->ar.end, i * 10); + KUNIT_EXPECT_EQ(test, r->ar.start, start); + KUNIT_EXPECT_EQ(test, r->ar.end, end); } + damon_free_target(t); +} + +static void damon_test_split_evenly_succ(struct kunit *test, + unsigned long start, unsigned long end, unsigned int nr_pieces) +{ + struct damon_target *t = damon_new_target(42); + struct damon_region *r = damon_new_region(start, end); + unsigned long expected_width = (end - start) / nr_pieces; + unsigned long i = 0; - t = damon_new_target(42); - r = damon_new_region(5, 59); damon_add_region(r, t); - KUNIT_EXPECT_EQ(test, damon_va_evenly_split_region(t, r, 5), 0); - KUNIT_EXPECT_EQ(test, damon_nr_regions(t), 5u); + KUNIT_EXPECT_EQ(test, + damon_va_evenly_split_region(t, r, nr_pieces), 0); + KUNIT_EXPECT_EQ(test, damon_nr_regions(t), nr_pieces); - i = 0; damon_for_each_region(r, t) { - if (i == 4) + if (i == nr_pieces - 1) break; - KUNIT_EXPECT_EQ(test, r->ar.start, 5 + 10 * i++); - KUNIT_EXPECT_EQ(test, r->ar.end, 5 + 10 * i); + KUNIT_EXPECT_EQ(test, + r->ar.start, start + i++ * expected_width); + KUNIT_EXPECT_EQ(test, r->ar.end, start + i * expected_width); } - KUNIT_EXPECT_EQ(test, r->ar.start, 5 + 10 * i); - KUNIT_EXPECT_EQ(test, r->ar.end, 59ul); + KUNIT_EXPECT_EQ(test, r->ar.start, start + i * expected_width); + KUNIT_EXPECT_EQ(test, r->ar.end, end); damon_free_target(t); +} - t = damon_new_target(42); - r = damon_new_region(5, 6); - damon_add_region(r, t); - KUNIT_EXPECT_EQ(test, damon_va_evenly_split_region(t, r, 2), -EINVAL); - KUNIT_EXPECT_EQ(test, damon_nr_regions(t), 1u); +static void damon_test_split_evenly(struct kunit *test) +{ + struct damon_ctx *c = damon_new_ctx(); + + KUNIT_EXPECT_EQ(test, damon_va_evenly_split_region(NULL, NULL, 5), + -EINVAL); + + damon_test_split_evenly_fail(test, 0, 100, 0); + damon_test_split_evenly_succ(test, 0, 100, 10); + damon_test_split_evenly_succ(test, 5, 59, 5); + damon_test_split_evenly_fail(test, 5, 6, 2); - damon_for_each_region(r, t) { - KUNIT_EXPECT_EQ(test, r->ar.start, 5ul); - KUNIT_EXPECT_EQ(test, r->ar.end, 6ul); - } - damon_free_target(t); damon_destroy_ctx(c); } -- 2.39.5 ^ permalink raw reply [flat|nested] 4+ messages in thread
* RE: [PATCH 5.15.y 1/2] mm/damon/vaddr-test: split a test function having >1024 bytes frame size 2024-12-06 18:16 ` [PATCH 5.15.y 1/2] mm/damon/vaddr-test: split a test function having >1024 bytes frame size SeongJae Park @ 2024-12-06 20:30 ` David Laight 0 siblings, 0 replies; 4+ messages in thread From: David Laight @ 2024-12-06 20:30 UTC (permalink / raw) To: 'SeongJae Park', stable Cc: damon, linux-mm, kernel test robot, Brendan Higgins, Shuah Khan, Andrew Morton, Linus Torvalds From: SeongJae Park > Sent: 06 December 2024 18:16 > > On some configuration[1], 'damon_test_split_evenly()' kunit test > function has >1024 bytes frame size, so below build warning is > triggered: > > CC mm/damon/vaddr.o > In file included from mm/damon/vaddr.c:672: > mm/damon/vaddr-test.h: In function 'damon_test_split_evenly': > mm/damon/vaddr-test.h:309:1: warning: the frame size of 1064 bytes is larger than 1024 bytes [- > Wframe-larger-than=] > 309 | } > | ^ > > This commit fixes the warning by separating the common logic in the > function. In that guaranteed to make any difference without some noinline_for_stack attributes? Not that I can see exactly where the stack was used. But it tends to be clang that doesn't re-use stack space. David > > [1] https://lore.kernel.org/linux-mm/202111182146.OV3C4uGr-lkp@intel.com/ > > Link: https://lkml.kernel.org/r/20211201150440.1088-6-sj@kernel.org > Fixes: 17ccae8bb5c9 ("mm/damon: add kunit tests") > Signed-off-by: SeongJae Park <sj@kernel.org> > Reported-by: kernel test robot <lkp@intel.com> > Cc: Brendan Higgins <brendanhiggins@google.com> > Cc: Shuah Khan <shuah@kernel.org> > Signed-off-by: Andrew Morton <akpm@linux-foundation.org> > Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> > (cherry picked from commit 044cd9750fe010170f5dc812e4824d98f5ea928c) > --- > mm/damon/vaddr-test.h | 77 ++++++++++++++++++++++--------------------- > 1 file changed, 40 insertions(+), 37 deletions(-) > > diff --git a/mm/damon/vaddr-test.h b/mm/damon/vaddr-test.h > index 1f5c13257dba..95ec362cdc37 100644 > --- a/mm/damon/vaddr-test.h > +++ b/mm/damon/vaddr-test.h > @@ -252,59 +252,62 @@ static void damon_test_apply_three_regions4(struct kunit *test) > new_three_regions, expected, ARRAY_SIZE(expected)); > } > > -static void damon_test_split_evenly(struct kunit *test) > +static void damon_test_split_evenly_fail(struct kunit *test, > + unsigned long start, unsigned long end, unsigned int nr_pieces) > { > - struct damon_ctx *c = damon_new_ctx(); > - struct damon_target *t; > - struct damon_region *r; > - unsigned long i; > - > - KUNIT_EXPECT_EQ(test, damon_va_evenly_split_region(NULL, NULL, 5), > - -EINVAL); > - > - t = damon_new_target(42); > - r = damon_new_region(0, 100); > - KUNIT_EXPECT_EQ(test, damon_va_evenly_split_region(t, r, 0), -EINVAL); > + struct damon_target *t = damon_new_target(42); > + struct damon_region *r = damon_new_region(start, end); > > damon_add_region(r, t); > - KUNIT_EXPECT_EQ(test, damon_va_evenly_split_region(t, r, 10), 0); > - KUNIT_EXPECT_EQ(test, damon_nr_regions(t), 10u); > + KUNIT_EXPECT_EQ(test, > + damon_va_evenly_split_region(t, r, nr_pieces), -EINVAL); > + KUNIT_EXPECT_EQ(test, damon_nr_regions(t), 1u); > > - i = 0; > damon_for_each_region(r, t) { > - KUNIT_EXPECT_EQ(test, r->ar.start, i++ * 10); > - KUNIT_EXPECT_EQ(test, r->ar.end, i * 10); > + KUNIT_EXPECT_EQ(test, r->ar.start, start); > + KUNIT_EXPECT_EQ(test, r->ar.end, end); > } > + > damon_free_target(t); > +} > + > +static void damon_test_split_evenly_succ(struct kunit *test, > + unsigned long start, unsigned long end, unsigned int nr_pieces) > +{ > + struct damon_target *t = damon_new_target(42); > + struct damon_region *r = damon_new_region(start, end); > + unsigned long expected_width = (end - start) / nr_pieces; > + unsigned long i = 0; > > - t = damon_new_target(42); > - r = damon_new_region(5, 59); > damon_add_region(r, t); > - KUNIT_EXPECT_EQ(test, damon_va_evenly_split_region(t, r, 5), 0); > - KUNIT_EXPECT_EQ(test, damon_nr_regions(t), 5u); > + KUNIT_EXPECT_EQ(test, > + damon_va_evenly_split_region(t, r, nr_pieces), 0); > + KUNIT_EXPECT_EQ(test, damon_nr_regions(t), nr_pieces); > > - i = 0; > damon_for_each_region(r, t) { > - if (i == 4) > + if (i == nr_pieces - 1) > break; > - KUNIT_EXPECT_EQ(test, r->ar.start, 5 + 10 * i++); > - KUNIT_EXPECT_EQ(test, r->ar.end, 5 + 10 * i); > + KUNIT_EXPECT_EQ(test, > + r->ar.start, start + i++ * expected_width); > + KUNIT_EXPECT_EQ(test, r->ar.end, start + i * expected_width); > } > - KUNIT_EXPECT_EQ(test, r->ar.start, 5 + 10 * i); > - KUNIT_EXPECT_EQ(test, r->ar.end, 59ul); > + KUNIT_EXPECT_EQ(test, r->ar.start, start + i * expected_width); > + KUNIT_EXPECT_EQ(test, r->ar.end, end); > damon_free_target(t); > +} > > - t = damon_new_target(42); > - r = damon_new_region(5, 6); > - damon_add_region(r, t); > - KUNIT_EXPECT_EQ(test, damon_va_evenly_split_region(t, r, 2), -EINVAL); > - KUNIT_EXPECT_EQ(test, damon_nr_regions(t), 1u); > +static void damon_test_split_evenly(struct kunit *test) > +{ > + struct damon_ctx *c = damon_new_ctx(); > + > + KUNIT_EXPECT_EQ(test, damon_va_evenly_split_region(NULL, NULL, 5), > + -EINVAL); > + > + damon_test_split_evenly_fail(test, 0, 100, 0); > + damon_test_split_evenly_succ(test, 0, 100, 10); > + damon_test_split_evenly_succ(test, 5, 59, 5); > + damon_test_split_evenly_fail(test, 5, 6, 2); > > - damon_for_each_region(r, t) { > - KUNIT_EXPECT_EQ(test, r->ar.start, 5ul); > - KUNIT_EXPECT_EQ(test, r->ar.end, 6ul); > - } > - damon_free_target(t); > damon_destroy_ctx(c); > } > > -- > 2.39.5 > - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales) ^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH 5.15.y 2/2] mm/damon/vaddr: fix issue in damon_va_evenly_split_region() 2024-12-06 18:16 ` [PATCH 5.15.y 0/2] fix issue in damon_va_evenly_split_region() SeongJae Park 2024-12-06 18:16 ` [PATCH 5.15.y 1/2] mm/damon/vaddr-test: split a test function having >1024 bytes frame size SeongJae Park @ 2024-12-06 18:16 ` SeongJae Park 1 sibling, 0 replies; 4+ messages in thread From: SeongJae Park @ 2024-12-06 18:16 UTC (permalink / raw) To: stable Cc: Zheng Yejian, damon, linux-mm, SeongJae Park, Fernand Sieber, Leonard Foerster, Shakeel Butt, Ye Weihua, Andrew Morton From: Zheng Yejian <zhengyejian@huaweicloud.com> Patch series "mm/damon/vaddr: Fix issue in damon_va_evenly_split_region()". v2. According to the logic of damon_va_evenly_split_region(), currently following split case would not meet the expectation: Suppose DAMON_MIN_REGION=0x1000, Case: Split [0x0, 0x3000) into 2 pieces, then the result would be acutually 3 regions: [0x0, 0x1000), [0x1000, 0x2000), [0x2000, 0x3000) but NOT the expected 2 regions: [0x0, 0x1000), [0x1000, 0x3000) !!! The root cause is that when calculating size of each split piece in damon_va_evenly_split_region(): `sz_piece = ALIGN_DOWN(sz_orig / nr_pieces, DAMON_MIN_REGION);` both the dividing and the ALIGN_DOWN may cause loss of precision, then each time split one piece of size 'sz_piece' from origin 'start' to 'end' would cause more pieces are split out than expected!!! To fix it, count for each piece split and make sure no more than 'nr_pieces'. In addition, add above case into damon_test_split_evenly(). And add 'nr_piece == 1' check in damon_va_evenly_split_region() for better code readability and add a corresponding kunit testcase. This patch (of 2): According to the logic of damon_va_evenly_split_region(), currently following split case would not meet the expectation: Suppose DAMON_MIN_REGION=0x1000, Case: Split [0x0, 0x3000) into 2 pieces, then the result would be acutually 3 regions: [0x0, 0x1000), [0x1000, 0x2000), [0x2000, 0x3000) but NOT the expected 2 regions: [0x0, 0x1000), [0x1000, 0x3000) !!! The root cause is that when calculating size of each split piece in damon_va_evenly_split_region(): `sz_piece = ALIGN_DOWN(sz_orig / nr_pieces, DAMON_MIN_REGION);` both the dividing and the ALIGN_DOWN may cause loss of precision, then each time split one piece of size 'sz_piece' from origin 'start' to 'end' would cause more pieces are split out than expected!!! To fix it, count for each piece split and make sure no more than 'nr_pieces'. In addition, add above case into damon_test_split_evenly(). After this patch, damon-operations test passed: # ./tools/testing/kunit/kunit.py run damon-operations [...] ============== damon-operations (6 subtests) =============== [PASSED] damon_test_three_regions_in_vmas [PASSED] damon_test_apply_three_regions1 [PASSED] damon_test_apply_three_regions2 [PASSED] damon_test_apply_three_regions3 [PASSED] damon_test_apply_three_regions4 [PASSED] damon_test_split_evenly ================ [PASSED] damon-operations ================= Link: https://lkml.kernel.org/r/20241022083927.3592237-1-zhengyejian@huaweicloud.com Link: https://lkml.kernel.org/r/20241022083927.3592237-2-zhengyejian@huaweicloud.com Fixes: 3f49584b262c ("mm/damon: implement primitives for the virtual memory address spaces") Signed-off-by: Zheng Yejian <zhengyejian@huaweicloud.com> Reviewed-by: SeongJae Park <sj@kernel.org> Cc: Fernand Sieber <sieberf@amazon.com> Cc: Leonard Foerster <foersleo@amazon.de> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Ye Weihua <yeweihua4@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> (cherry picked from commit f3c7a1ede435e2e45177d7a490a85fb0a0ec96d1) --- mm/damon/vaddr-test.h | 1 + mm/damon/vaddr.c | 4 ++-- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/mm/damon/vaddr-test.h b/mm/damon/vaddr-test.h index 95ec362cdc37..5531766ff09f 100644 --- a/mm/damon/vaddr-test.h +++ b/mm/damon/vaddr-test.h @@ -306,6 +306,7 @@ static void damon_test_split_evenly(struct kunit *test) damon_test_split_evenly_fail(test, 0, 100, 0); damon_test_split_evenly_succ(test, 0, 100, 10); damon_test_split_evenly_succ(test, 5, 59, 5); + damon_test_split_evenly_succ(test, 0, 3, 2); damon_test_split_evenly_fail(test, 5, 6, 2); damon_destroy_ctx(c); diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c index 6ad96da15081..6d8036671e60 100644 --- a/mm/damon/vaddr.c +++ b/mm/damon/vaddr.c @@ -69,6 +69,7 @@ static int damon_va_evenly_split_region(struct damon_target *t, unsigned long sz_orig, sz_piece, orig_end; struct damon_region *n = NULL, *next; unsigned long start; + unsigned int i; if (!r || !nr_pieces) return -EINVAL; @@ -82,8 +83,7 @@ static int damon_va_evenly_split_region(struct damon_target *t, r->ar.end = r->ar.start + sz_piece; next = damon_next_region(r); - for (start = r->ar.end; start + sz_piece <= orig_end; - start += sz_piece) { + for (start = r->ar.end, i = 1; i < nr_pieces; start += sz_piece, i++) { n = damon_new_region(start, start + sz_piece); if (!n) return -ENOMEM; -- 2.39.5 ^ permalink raw reply [flat|nested] 4+ messages in thread
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[not found] <2024120625-recycling-till-0cca@gregkh>
2024-12-06 18:16 ` [PATCH 5.15.y 0/2] fix issue in damon_va_evenly_split_region() SeongJae Park
2024-12-06 18:16 ` [PATCH 5.15.y 1/2] mm/damon/vaddr-test: split a test function having >1024 bytes frame size SeongJae Park
2024-12-06 20:30 ` David Laight
2024-12-06 18:16 ` [PATCH 5.15.y 2/2] mm/damon/vaddr: fix issue in damon_va_evenly_split_region() SeongJae Park
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