Move memory docs to docs/memory-infra
I replaced the old documents with links that redirect to
the new locations so we don't break external links.
Also fixes a couple of broken links I found.
BUG=chromium:663353
Review-Url: https://codereview.chromium.org/2494063002
Cr-Commit-Position: refs/heads/master@{#431920}
diff --git a/docs/memory-infra/README.md b/docs/memory-infra/README.md
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+# MemoryInfra
+
+MemoryInfra is a timeline-based profiling system integrated in chrome://tracing.
+It aims at creating Chrome-scale memory measurement tooling so that on any
+Chrome in the world --- desktop, mobile, Chrome OS or any other --- with the
+click of a button you can understand where memory is being used in your system.
+
+[TOC]
+
+## Getting Started
+
+ 1. Get a bleeding-edge or tip-of-tree build of Chrome.
+
+ 2. [Record a trace as usual][record-trace]: open [chrome://tracing][tracing]
+ on Desktop Chrome or [chrome://inspect?tracing][inspect-tracing] to trace
+ Chrome for Android.
+
+ 3. Make sure to enable the **memory-infra** category on the right.
+
+ ![Tick the memory-infra checkbox when recording a trace.][memory-infra-box]
+
+ 4. For now, some subsystems only work if Chrome is started with the
+ `--no-sandbox` flag.
+ <!-- TODO(primiano) TODO(ssid): https://crbug.com/461788 -->
+
+[record-trace]: https://sites.google.com/a/chromium.org/dev/developers/how-tos/trace-event-profiling-tool/recording-tracing-runs
+[tracing]: chrome://tracing
+[inspect-tracing]: chrome://inspect?tracing
+[memory-infra-box]: https://storage.googleapis.com/chromium-docs.appspot.com/1c6d1886584e7cc6ffed0d377f32023f8da53e02
+
+![Timeline View and Analysis View][tracing-views]
+
+After recording a trace, you will see the **timeline view**. Timeline view
+shows:
+
+ * Total resident memory grouped by process (at the top).
+ * Total resident memory grouped by subsystem (at the top).
+ * Allocated memory per subsystem for every process.
+
+Click one of the ![M][m-blue] dots to bring up the **analysis view**. Click
+on a cell in analysis view to reveal more information about its subsystem.
+PartitionAlloc for instance, has more details about its partitions.
+
+![Component details for PartitionAlloc][partalloc-details]
+
+The purple ![M][m-purple] dots represent heavy dumps. In these dumps, components
+can provide more details than in the regular dumps. The full details of the
+MemoryInfra UI are explained in its [design doc][mi-ui-doc].
+
+[tracing-views]: https://storage.googleapis.com/chromium-docs.appspot.com/db12015bd262385f0f8bd69133330978a99da1ca
+[m-blue]: https://storage.googleapis.com/chromium-docs.appspot.com/b60f342e38ff3a3767bbe4c8640d96a2d8bc864b
+[partalloc-details]: https://storage.googleapis.com/chromium-docs.appspot.com/02eade61d57c83f8ef8227965513456555fc3324
+[m-purple]: https://storage.googleapis.com/chromium-docs.appspot.com/d7bdf4d16204c293688be2e5a0bcb2bf463dbbc3
+[mi-ui-doc]: https://docs.google.com/document/d/1b5BSBEd1oB-3zj_CBAQWiQZ0cmI0HmjmXG-5iNveLqw/edit
+
+## Columns
+
+**Columns in blue** reflect the amount of actual physical memory used by the
+process. This is what exerts memory pressure on the system.
+
+ * **Total Resident**: (TODO: document this).
+ * **Peak Total Resident**: (TODO: document this).
+ * **PSS**: (TODO: document this).
+ * **Private Dirty**: (TODO: document this).
+ * **Swapped**: (TODO: document this).
+
+**Columns in black** reflect a best estimation of the the amount of physical
+memory used by various subsystems of Chrome.
+
+ * **Blink GC**: Memory used by [Oilpan][oilpan].
+ * **CC**: Memory used by the compositor.
+ See [cc/memory][cc-memory] for the full details.
+ * **Discardable**: (TODO: document this).
+ * **Font Caches**: (TODO: document this).
+ * **GPU** and **GPU Memory Buffer**: GPU memory and RAM used for GPU purposes.
+ See [GPU Memory Tracing][gpu-memory].
+ * **LevelDB**: (TODO: document this).
+ * **Malloc**: Memory allocated by calls to `malloc`, or `new` for most
+ non-Blink objects.
+ * **PartitionAlloc**: Memory allocated via [PartitionAlloc][partalloc].
+ Blink objects that are not managed by Oilpan are allocated with
+ PartitionAlloc.
+ * **Skia**: (TODO: document this).
+ * **SQLite**: (TODO: document this).
+ * **V8**: (TODO: document this).
+ * **Web Cache**: (TODO: document this).
+
+The **tracing column in gray** reports memory that is used to collect all of the
+above information. This memory would not be used if tracing were not enabled,
+and it is discounted from malloc and the blue columns.
+
+<!-- TODO(primiano): Improve this. https://crbug.com/??? -->
+
+[oilpan]: /third_party/WebKit/Source/platform/heap/BlinkGCDesign.md
+[cc-memory]: probe-cc.md
+[gpu-memory]: probe-gpu.md
+[partalloc]: /third_party/WebKit/Source/wtf/allocator/PartitionAlloc.md
+
+## Related Pages
+
+ * [Adding MemoryInfra Tracing to a Component](adding_memory_infra_tracing.md)
+ * [GPU Memory Tracing](probe-gpu.md)
+ * [Heap Profiler Internals](heap_profiler_internals.md)
+ * [Heap Profiling with MemoryInfra](heap_profiler.md)
+ * [Startup Tracing with MemoryInfra](memory_infra_startup_tracing.md)
+
+## Rationale
+
+Another memory profiler? What is wrong with tool X?
+Most of the existing tools:
+
+ * Are hard to get working with Chrome. (Massive symbols, require OS-specific
+ tricks.)
+ * Lack Chrome-related context.
+ * Don't deal with multi-process scenarios.
+
+MemoryInfra leverages the existing tracing infrastructure in Chrome and provides
+contextual data:
+
+ * **It speaks Chrome slang.**
+ The Chromium codebase is instrumented. Its memory subsystems (allocators,
+ caches, etc.) uniformly report their stats into the trace in a way that can
+ be understood by Chrome developers. No more
+ `__gnu_cxx::new_allocator< std::_Rb_tree_node< std::pair< std::string const, base::Value*>>> ::allocate`.
+ * **Timeline data that can be correlated with other events.**
+ Did memory suddenly increase during a specific Blink / V8 / HTML parsing
+ event? Which subsystem increased? Did memory not go down as expected after
+ closing a tab? Which other threads were active during a bloat?
+ * **Works out of the box on desktop and mobile.**
+ No recompilations with unmaintained `GYP_DEFINES`, no time-consuming
+ symbolizations stages. All the logic is already into Chrome, ready to dump at
+ any time.
+ * **The same technology is used for telemetry and the ChromePerf dashboard.**
+ See [the slides][chromeperf-slides] and take a look at
+ [some ChromePerf dashboards][chromeperf] and
+ [telemetry documentation][telemetry].
+
+[chromeperf-slides]: https://docs.google.com/presentation/d/1OyxyT1sfg50lA36A7ibZ7-bBRXI1kVlvCW0W9qAmM_0/present?slide=id.gde150139b_0_137
+[chromeperf]: https://chromeperf.appspot.com/report?sid=3b54e60c9951656574e19252fadeca846813afe04453c98a49136af4c8820b8d
+[telemetry]: https://catapult.gsrc.io/telemetry
+
+## Development
+
+MemoryInfra is based on a simple and extensible architecture. See
+[the slides][dp-slides] on how to get your subsystem reported in MemoryInfra,
+or take a look at one of the existing examples such as
+[malloc_dump_provider.cc][malloc-dp]. The crbug label is
+[Hotlist-MemoryInfra][hotlist]. Don't hesitate to contact
+[[email protected]][mailtracing] for questions and support.
+
+[dp-slides]: https://docs.google.com/presentation/d/1GI3HY3Mm5-Mvp6eZyVB0JiaJ-u3L1MMJeKHJg4lxjEI/present?slide=id.g995514d5c_1_45
+[malloc-dp]: https://chromium.googlesource.com/chromium/src.git/+/master/base/trace_event/malloc_dump_provider.cc
+[hotlist]: https://code.google.com/p/chromium/issues/list?q=label:Hotlist-MemoryInfra
+[mailtracing]: mailto:[email protected]
+
+## Design documents
+
+Architectural:
+
+<iframe width="100%" height="300px" src="https://docs.google.com/a/google.com/embeddedfolderview?id=0B3KuDeqD-lVJfmp0cW1VcE5XVWNxZndxelV5T19kT2NFSndYZlNFbkFpc3pSa2VDN0hlMm8">
+</iframe>
+
+Chrome-side design docs:
+
+<iframe width="100%" height="300px" src="https://docs.google.com/a/google.com/embeddedfolderview?id=0B3KuDeqD-lVJfndSa2dleUQtMnZDeWpPZk1JV0QtbVM5STkwWms4YThzQ0pGTmU1QU9kNVk">
+</iframe>
+
+Catapult-side design docs:
+
+<iframe width="100%" height="300px" src="https://docs.google.com/a/google.com/embeddedfolderview?id=0B3KuDeqD-lVJfm10bXd5YmRNWUpKOElOWS0xdU1tMmV1S3F4aHo0ZDJLTmtGRy1qVnQtVWM">
+</iframe>
