gecko-dev/memory
Nicholas Nethercote 57c26c9834 Bug 1387956 - Overhaul ComputedValues measurement, and add style structs measurement. r=bholley.
This patch moves measurement of ComputedValues objects from Rust to C++.
Measurement now happens (a) via DOM elements and (b) remaining elements via
the frame tree. Likewise for the style structs hanging off ComputedValues
objects.

Here is an example of the output.

> ├──27,600,448 B (26.49%) -- active/window(https://en.wikipedia.org/wiki/Barack_Obama)
> │  ├──12,772,544 B (12.26%) -- layout
> │  │  ├───4,483,744 B (04.30%) -- frames
> │  │  │   ├──1,653,552 B (01.59%) ── nsInlineFrame
> │  │  │   ├──1,415,760 B (01.36%) ── nsTextFrame
> │  │  │   ├────431,376 B (00.41%) ── nsBlockFrame
> │  │  │   ├────340,560 B (00.33%) ── nsHTMLScrollFrame
> │  │  │   ├────302,544 B (00.29%) ── nsContinuingTextFrame
> │  │  │   ├────156,408 B (00.15%) ── nsBulletFrame
> │  │  │   ├─────73,024 B (00.07%) ── nsPlaceholderFrame
> │  │  │   ├─────27,656 B (00.03%) ── sundries
> │  │  │   ├─────23,520 B (00.02%) ── nsTableCellFrame
> │  │  │   ├─────16,704 B (00.02%) ── nsImageFrame
> │  │  │   ├─────15,488 B (00.01%) ── nsTableRowFrame
> │  │  │   ├─────13,776 B (00.01%) ── nsTableColFrame
> │  │  │   └─────13,376 B (00.01%) ── nsTableFrame
> │  │  ├───3,412,192 B (03.28%) -- servo-style-structs
> │  │  │   ├──1,288,224 B (01.24%) ── Display
> │  │  │   ├────742,400 B (00.71%) ── Position
> │  │  │   ├────308,736 B (00.30%) ── Font
> │  │  │   ├────226,512 B (00.22%) ── Background
> │  │  │   ├────218,304 B (00.21%) ── TextReset
> │  │  │   ├────214,896 B (00.21%) ── Text
> │  │  │   ├────130,560 B (00.13%) ── Border
> │  │  │   ├─────81,408 B (00.08%) ── UIReset
> │  │  │   ├─────61,440 B (00.06%) ── Padding
> │  │  │   ├─────38,176 B (00.04%) ── UserInterface
> │  │  │   ├─────29,232 B (00.03%) ── Margin
> │  │  │   ├─────21,824 B (00.02%) ── sundries
> │  │  │   ├─────20,080 B (00.02%) ── Color
> │  │  │   ├─────20,080 B (00.02%) ── Column
> │  │  │   └─────10,320 B (00.01%) ── Effects
> │  │  ├───2,227,680 B (02.14%) -- computed-values
> │  │  │   ├──1,182,928 B (01.14%) ── non-dom
> │  │  │   └──1,044,752 B (01.00%) ── dom
> │  │  ├───1,500,016 B (01.44%) ── text-runs
> │  │  ├─────492,640 B (00.47%) ── line-boxes
> │  │  ├─────326,688 B (00.31%) ── frame-properties
> │  │  ├─────301,760 B (00.29%) ── pres-shell
> │  │  ├──────27,648 B (00.03%) ── pres-contexts
> │  │  └─────────176 B (00.00%) ── style-sets

The 'servo-style-structs' and 'computed-values' sub-trees are new. (Prior to
this patch, ComputedValues under DOM elements were tallied under the the
'dom/element-nodes' sub-tree, and ComputedValues not under DOM element were
ignored.) 'servo-style-structs/sundries' aggregates all the style structs that
are smaller than 8 KiB.

Other notable things done by the patch are as follows.

- It significantly changes the signatures of the methods measuring nsINode and
  its subclasses, in order to handle the tallying of style structs separately
  from element-nodes. Likewise for nsIFrame.

- It renames the 'layout/style-structs' sub-tree as
  'layout/gecko-style-structs', to clearly distinguish it from the new
  'layout/servo-style-structs' sub-tree.

- It adds some FFI functions to access various Rust-side data structures from
  C++ code.

- There is a nasty hack used twice to measure Arcs, by stepping backwards from
  an interior pointer to a base pointer. It works, but I want to replace it
  with something better eventually. The "XXX WARNING" comments have details.

- It makes DMD print a line to the console if it sees a pointer it doesn't
  recognise. This is useful for detecting when we are measuring an interior
  pointer instead of a base pointer, which is bad but easy to do when Arcs are
  involved.

- It removes the Rust code for measuring CVs, because it's now all done on the
  C++ side.

MozReview-Commit-ID: BKebACLKtCi

--HG--
extra : rebase_source : 4d9a8c6b198a0ff025b811759a6bfa9f33a260ba
2017-08-11 16:37:33 +10:00
..
build Bug 1382099 - Remove MOZ_WIDGET_GONK from memory/. r=glandium. 2017-07-19 18:39:00 +10:00
fallible Bug 1290645 - Remove VS2013 workarounds in memory/. r=glandium 2016-07-28 11:46:30 -07:00
gtest Bug 1313485 - Convert XPCOM test TestJemalloc to a gtest. r=njn 2016-11-09 10:24:22 -08:00
mozalloc Bug 1383919 - Use |noexcept| instead of an exception-specification in mozalloc.h. r=glandium 2017-07-24 19:19:07 -04:00
mozjemalloc Bug 1388935 - Avoid overflowing the chunk recycling limit with very large chunks. r=njn 2017-08-10 09:22:55 +09:00
replace Bug 1387956 - Overhaul ComputedValues measurement, and add style structs measurement. r=bholley. 2017-08-11 16:37:33 +10:00
volatile Bug 1382099 - Remove MOZ_WIDGET_GONK from memory/. r=glandium. 2017-07-19 18:39:00 +10:00
moz.build Bug 1363992 - Remove jemalloc 4. r=njn 2017-05-11 13:23:07 +09:00