Allocate the fixed-size timeline buffer with virtual memory instead of malloc.

Allocate the fixed-size timeline buffer with virtual memory instead of malloc.

Allows naming the memory region; removes some pressure from jemalloc.

R=zra@google.com

Committed: https://github.com/dart-lang/sdk/commit/00290c3813751cc7ee78a1dc631d962d903d0859

[rmacnak, 2017-07-27 18:18:27]

Description was changed from

==========
Allocate the fixed-size timeline buffer with virtual memory instead of malloc.

Allows naming the memory regions; removes some pressure from jemalloc.
==========

to

==========
Allocate the fixed-size timeline buffer with virtual memory instead of malloc.

Allows naming the memory region; removes some pressure from jemalloc.
==========

[rmacnak, 2017-07-27 18:51:49]

rmacnak@google.com changed reviewers:
+ zra@google.com

[zra, 2017-07-27 19:05:45]

lgtm

https://codereview.chromium.org/2984313002/diff/1/runtime/vm/timeline.h
File runtime/vm/timeline.h (right):

https://codereview.chromium.org/2984313002/diff/1/runtime/vm/timeline.h#newco...
runtime/vm/timeline.h:30: class VirtualMemory;
Why can't/shouldn't this #include "vm/virtual_memory.h" ?

[rmacnak, 2017-07-27 20:24:33]

https://codereview.chromium.org/2984313002/diff/1/runtime/vm/timeline.h
File runtime/vm/timeline.h (right):

https://codereview.chromium.org/2984313002/diff/1/runtime/vm/timeline.h#newco...
runtime/vm/timeline.h:30: class VirtualMemory;
On 2017/07/27 19:05:44, zra wrote:
> Why can't/shouldn't this #include "vm/virtual_memory.h" ?

It doesn't need it. timeline.h gets included in a lot of places in the VM, and
I'd like to avoid them indirectly including more and more headers.

[rmacnak, 2017-07-27 20:37:46]

Description was changed from

==========
Allocate the fixed-size timeline buffer with virtual memory instead of malloc.

Allows naming the memory region; removes some pressure from jemalloc.
==========

to

==========
Allocate the fixed-size timeline buffer with virtual memory instead of malloc.

Allows naming the memory region; removes some pressure from jemalloc.

R=zra@google.com

Committed:
https://github.com/dart-lang/sdk/commit/00290c3813751cc7ee78a1dc631d962d903d0859
==========

[rmacnak, 2017-07-27 20:37:47]

Committed patchset #1 (id:1) manually as
00290c3813751cc7ee78a1dc631d962d903d0859 (presubmit successful).