Mark Vec::drop() as #[inline] #102554

nikic · 2022-10-01T21:44:28Z

As seen in #102539 (comment), Vec::drop() is commonly a no-op, if the underlying type does not need drop. Checking to see what the impact of this would be, I'm not sure the change can be done in this form (an alternative would be to do a needs_drop check and only instantiate that part in each CGU).

r? @ghost

rustbot · 2022-10-01T21:44:30Z

Hey! It looks like you've submitted a new PR for the library teams!

If this PR contains changes to any rust-lang/rust public library APIs then please comment with @rustbot label +T-libs-api -T-libs to tag it appropriately. If this PR contains changes to any unstable APIs please edit the PR description to add a link to the relevant API Change Proposal or create one if you haven't already. If you're unsure where your change falls no worries, just leave it as is and the reviewer will take a look and make a decision to forward on if necessary.

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nikic · 2022-10-01T21:44:53Z

@bors try @rust-timer queue

rust-timer · 2022-10-01T21:44:54Z

Awaiting bors try build completion.

@rustbot label: +S-waiting-on-perf

bors · 2022-10-01T21:45:01Z

⌛ Trying commit 0b66d5f with merge 0313714872a1265ca2e99812c4bd550ede699c36...

bors · 2022-10-01T23:23:42Z

☀️ Try build successful - checks-actions
Build commit: 0313714872a1265ca2e99812c4bd550ede699c36 (0313714872a1265ca2e99812c4bd550ede699c36)

rust-timer · 2022-10-01T23:23:43Z

Queued 0313714872a1265ca2e99812c4bd550ede699c36 with parent 56a35bc, future comparison URL.

rust-timer · 2022-10-02T09:15:34Z

Finished benchmarking commit (0313714872a1265ca2e99812c4bd550ede699c36): comparison URL.

Overall result: ❌✅ regressions and improvements - ACTION NEEDED

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. While you can manually mark this PR as fit for rollup, we strongly recommend not doing so since this PR may lead to changes in compiler perf.

Next Steps: If you can justify the regressions found in this try perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please fix the regressions and do another perf run. If the next run shows neutral or positive results, the label will be automatically removed.

@bors rollup=never
@rustbot label: +S-waiting-on-review -S-waiting-on-perf +perf-regression

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

	mean¹	range	count²
Regressions ❌ (primary)	2.4%	[0.4%, 10.3%]	25
Regressions ❌ (secondary)	0.4%	[0.2%, 0.8%]	11
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.8%	[-1.1%, -0.4%]	9
All ❌✅ (primary)	2.4%	[0.4%, 10.3%]	25

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean¹	range	count²
Regressions ❌ (primary)	3.0%	[2.5%, 3.5%]	2
Regressions ❌ (secondary)	3.7%	[1.4%, 6.2%]	6
Improvements ✅ (primary)	-2.8%	[-2.8%, -2.8%]	1
Improvements ✅ (secondary)	-4.6%	[-7.1%, -2.2%]	3
All ❌✅ (primary)	1.1%	[-2.8%, 3.5%]	3

Cycles

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean¹	range	count²
Regressions ❌ (primary)	3.9%	[1.4%, 11.8%]	16
Regressions ❌ (secondary)	3.4%	[2.5%, 4.7%]	9
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	3.9%	[1.4%, 11.8%]	16

the arithmetic mean of the percent change ↩ ↩² ↩³
number of relevant changes ↩ ↩² ↩³

nikic · 2022-10-02T10:14:27Z

@bors try @rust-timer queue

rust-timer · 2022-10-02T10:14:29Z

Awaiting bors try build completion.

@rustbot label: +S-waiting-on-perf

bors · 2022-10-02T10:14:36Z

⌛ Trying commit f17487c with merge d90a71088abba338d8ce895e5629606839186f7c...

rust-log-analyzer · 2022-10-02T10:38:31Z

The job mingw-check failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

configure: rust.debug-assertions := True
configure: rust.overflow-checks := True
configure: llvm.assertions      := True
configure: dist.missing-tools   := True
configure: build.configure-args := ['--enable-sccache', '--disable-manage-submodu ...
configure: writing `config.toml` in current directory
configure: 
configure: run `python /checkout/x.py --help`
Attempting with retry: make prepare
---
skip untracked path cpu-usage.csv during rustfmt invocations
skip untracked path src/doc/book/ during rustfmt invocations
skip untracked path src/doc/rust-by-example/ during rustfmt invocations
skip untracked path src/llvm-project/ during rustfmt invocations
Diff in /checkout/library/alloc/src/vec/mod.rs at line 2924:
                     ptr::drop_in_place(ptr::slice_from_raw_parts_mut(vec.as_mut_ptr(), vec.len))
             }
             }
-            unsafe { drop_via_slice(self); }
+            unsafe {
+                drop_via_slice(self);
         }
         }
         // RawVec handles deallocation
     }
Running `"/checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/rustfmt" "--config-path" "/checkout" "--edition" "2021" "--unstable-features" "--skip-children" "--check" "/checkout/library/alloc/src/alloc/tests.rs" "/checkout/library/alloc/src/vec/drain_filter.rs" "/checkout/library/alloc/src/raw_vec.rs" "/checkout/library/alloc/src/vec/mod.rs" "/checkout/library/alloc/src/rc.rs" "/checkout/library/alloc/src/vec/spec_extend.rs" "/checkout/library/alloc/src/string.rs" "/checkout/library/alloc/src/vec/into_iter.rs"` failed.
If you're running `tidy`, try again with `--bless`. Or, if you just want to format code, run `./x.py fmt` instead.

bors · 2022-10-02T12:04:54Z

☀️ Try build successful - checks-actions
Build commit: d90a71088abba338d8ce895e5629606839186f7c (d90a71088abba338d8ce895e5629606839186f7c)

bors · 2022-10-02T12:04:54Z

☀️ Try build successful - checks-actions
Build commit: d90a71088abba338d8ce895e5629606839186f7c (d90a71088abba338d8ce895e5629606839186f7c)

rust-timer · 2022-10-02T12:04:55Z

Queued d90a71088abba338d8ce895e5629606839186f7c with parent c2590e6, future comparison URL.

rust-timer · 2022-10-02T16:05:04Z

Finished benchmarking commit (d90a71088abba338d8ce895e5629606839186f7c): comparison URL.

Overall result: ❌✅ regressions and improvements - ACTION NEEDED

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. While you can manually mark this PR as fit for rollup, we strongly recommend not doing so since this PR may lead to changes in compiler perf.

Next Steps: If you can justify the regressions found in this try perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please fix the regressions and do another perf run. If the next run shows neutral or positive results, the label will be automatically removed.

@bors rollup=never
@rustbot label: +S-waiting-on-review -S-waiting-on-perf +perf-regression

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

	mean¹	range	count²
Regressions ❌ (primary)	2.6%	[0.3%, 6.2%]	23
Regressions ❌ (secondary)	2.2%	[0.4%, 5.5%]	5
Improvements ✅ (primary)	-0.7%	[-0.8%, -0.5%]	2
Improvements ✅ (secondary)	-1.4%	[-1.9%, -0.9%]	8
All ❌✅ (primary)	2.3%	[-0.8%, 6.2%]	25

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean¹	range	count²
Regressions ❌ (primary)	3.2%	[3.2%, 3.2%]	1
Regressions ❌ (secondary)	3.0%	[2.9%, 3.1%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	3.2%	[3.2%, 3.2%]	1

Cycles

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean¹	range	count²
Regressions ❌ (primary)	3.8%	[1.9%, 6.8%]	15
Regressions ❌ (secondary)	4.7%	[2.9%, 6.5%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	3.8%	[1.9%, 6.8%]	15

the arithmetic mean of the percent change ↩ ↩² ↩³
number of relevant changes ↩ ↩² ↩³

nikic · 2022-10-02T18:42:43Z

Those are some surprisingly large effects, but not positive ones... Clearly not worthwhile in this form.

Mark Vec::drop() as #[inline]

0b66d5f

rustbot added the T-libs Relevant to the library team, which will review and decide on the PR/issue. label Oct 1, 2022

rustbot added the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Oct 1, 2022

rustbot added perf-regression Performance regression. S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-perf Status: Waiting on a perf run to be completed. labels Oct 2, 2022

Only inline needs_drop check

f17487c

rustbot added the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Oct 2, 2022

rustbot removed the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Oct 2, 2022

nikic closed this Oct 2, 2022

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Mark Vec::drop() as #[inline] #102554

Mark Vec::drop() as #[inline] #102554

nikic commented Oct 1, 2022

rustbot commented Oct 1, 2022

nikic commented Oct 1, 2022

rust-timer commented Oct 1, 2022

bors commented Oct 1, 2022

bors commented Oct 1, 2022

rust-timer commented Oct 1, 2022

rust-timer commented Oct 2, 2022

nikic commented Oct 2, 2022

rust-timer commented Oct 2, 2022

bors commented Oct 2, 2022

rust-log-analyzer commented Oct 2, 2022

bors commented Oct 2, 2022

bors commented Oct 2, 2022

rust-timer commented Oct 2, 2022

rust-timer commented Oct 2, 2022

nikic commented Oct 2, 2022

Mark Vec::drop() as #[inline] #102554

Mark Vec::drop() as #[inline] #102554

Conversation

nikic commented Oct 1, 2022

rustbot commented Oct 1, 2022

nikic commented Oct 1, 2022

rust-timer commented Oct 1, 2022

bors commented Oct 1, 2022

bors commented Oct 1, 2022

rust-timer commented Oct 1, 2022

rust-timer commented Oct 2, 2022

Overall result: ❌✅ regressions and improvements - ACTION NEEDED

Instruction count

Max RSS (memory usage)

Cycles

Footnotes

nikic commented Oct 2, 2022

rust-timer commented Oct 2, 2022

bors commented Oct 2, 2022

rust-log-analyzer commented Oct 2, 2022

bors commented Oct 2, 2022

bors commented Oct 2, 2022

rust-timer commented Oct 2, 2022

rust-timer commented Oct 2, 2022

Overall result: ❌✅ regressions and improvements - ACTION NEEDED

Instruction count

Max RSS (memory usage)

Cycles

Footnotes

nikic commented Oct 2, 2022