Revert "Added a call to ActivityManager.isLowRamDevice() from SysUtils.detectLowEndDevice()."

Revert "Added a call to ActivityManager.isLowRamDevice() from SysUtils.detectLowEndDevice()."

This reverts commit 80dc8d87cfd1ef70541c101a355965f3a7a74415.

Some devices in the wild with 1GB of RAM are returning true for
ActivityManager.isLowRamDevice(), causing us to inappropriately enable
aggressive memory optimizations designed for 512MB devices.  Change back
to only considering the true memory capacity of the device.

BUG=568192, 459781
Committed: https://crrev.com/1dc262725270493bf333d53888319acacc5e8baa
Cr-Commit-Position: refs/heads/master@{#364619}

[aelias_OOO_until_Jul13, 2015-12-09 23:45:13]

aelias@chromium.org changed reviewers:
+ petrcermak@chromium.org, yfriedman@chromium.org

[aelias_OOO_until_Jul13, 2015-12-09 23:48:30]

[+yfriedman] for OWNERS.

Petr, your original patch https://codereview.chromium.org/766873002 included no
reason why you were adding this code.  Just to double-check, do you know of any
cases where looking at isLowRamDevice improves our accuracy instead of making it
worse (for example if amountOfPhysicalMemoryKb() might return the wrong value on
certain devices)?

[aelias_OOO_until_Jul13, 2015-12-09 23:52:32]

Description was changed from

==========
Revert "Added a call to ActivityManager.isLowRamDevice() from
SysUtils.detectLowEndDevice()."

This reverts commit 80dc8d87cfd1ef70541c101a355965f3a7a74415.

Some devices in the wild with 1GB of RAM are returning true for
ActivityManager.isLowRamDevice(), causing us to inappropriately enable
aggressive memory optimizations designed for 512MB devices.  Change back
to only considering the true memory capacity of the device.

BUG=568192
==========

to

==========
Revert "Added a call to ActivityManager.isLowRamDevice() from
SysUtils.detectLowEndDevice()."

This reverts commit 80dc8d87cfd1ef70541c101a355965f3a7a74415.

Some devices in the wild with 1GB of RAM are returning true for
ActivityManager.isLowRamDevice(), causing us to inappropriately enable
aggressive memory optimizations designed for 512MB devices.  Change back
to only considering the true memory capacity of the device.

BUG=568192, 459781
==========

[petrcermak, 2015-12-10 09:00:39]

petrcermak@chromium.org changed reviewers:
+ rmcilroy@chromium.org

[petrcermak, 2015-12-10 09:00:40]

I think that the rationale was to get more precise information when deciding
whether to use shared relros
(https://code.google.com/p/chromium/codesearch#chromium/src/base/android/java/...).

+rmcilroy

Petr

[rmcilroy, 2015-12-10 11:21:49]

I believe the reasoning was that if the device had been built as a Svelte device
by the OEM (meaning that activityManager.isLowRamDevice() returns true) then we
should perform our Svelte memory optimizations on that device. I'm not sure why
a manufacturer would set a > 512MB device to be Svelte mode, but maybe they
carve out big chunks of the physical memory for GPU memory or other carveouts
which make it behave more like a 512MB device. I don't particularly object to
just looking at memory size, but there is a comment in
https://code.google.com/p/chromium/issues/detail?id=459781#c7 that we should
respect isLowRamDevice() for the tab switcher (but use physical memory for
things like the tile cache).

[aelias_OOO_until_Jul13, 2015-12-10 20:30:42]

On 2015/12/10 at 11:21:49, rmcilroy wrote:
> I believe the reasoning was that if the device had been built as a Svelte
device by the OEM (meaning that activityManager.isLowRamDevice() returns true)
then we should perform our Svelte memory optimizations on that device. I'm not
sure why a manufacturer would set a > 512MB device to be Svelte mode, but maybe
they carve out big chunks of the physical memory for GPU memory or other
carveouts which make it behave more like a 512MB device.

Devices carve out space from the amountOfPhysicalMemoryKB() for such reserved
memory areas, that's why 512MB devices typically report a number <400MB for
that.  There's no additional value from isLowRamDevice() in that respect.

> I don't particularly object to just looking at memory size, but there is a
comment in https://code.google.com/p/chromium/issues/detail?id=459781#c7 that we
should respect isLowRamDevice() for the tab switcher (but use physical memory
for things like the tile cache).

Today in https://code.google.com/p/chromium/issues/detail?id=568192#6 Grace said
"I am OK with explicit memory size." so it seems no one has any remaining
objection to landing this.  I just need OWNERS lgt'm to land.

[Yaron, 2015-12-11 02:29:14]

On 2015/12/10 20:30:42, aelias wrote:
> On 2015/12/10 at 11:21:49, rmcilroy wrote:
> > I believe the reasoning was that if the device had been built as a Svelte
> device by the OEM (meaning that activityManager.isLowRamDevice() returns true)
> then we should perform our Svelte memory optimizations on that device. I'm not
> sure why a manufacturer would set a > 512MB device to be Svelte mode, but
maybe
> they carve out big chunks of the physical memory for GPU memory or other
> carveouts which make it behave more like a 512MB device.
> 
> Devices carve out space from the amountOfPhysicalMemoryKB() for such reserved
> memory areas, that's why 512MB devices typically report a number <400MB for
> that.  There's no additional value from isLowRamDevice() in that respect.
> 
> > I don't particularly object to just looking at memory size, but there is a
> comment in https://code.google.com/p/chromium/issues/detail?id=459781#c7 that
we
> should respect isLowRamDevice() for the tab switcher (but use physical memory
> for things like the tile cache).
> 
> Today in https://code.google.com/p/chromium/issues/detail?id=568192#6 Grace
said
> "I am OK with explicit memory size." so it seems no one has any remaining
> objection to landing this.  I just need OWNERS lgt'm to land.

lgtm

[aelias_OOO_until_Jul13, 2015-12-11 03:39:38]

The CQ bit was checked by aelias@chromium.org

[aelias_OOO_until_Jul13, 2015-12-11 03:39:39]

The patchset sent to the CQ was uploaded after l-g-t-m from
yfriedman@chromium.org
Link to the patchset: https://codereview.chromium.org/1514713002/#ps20001
(title: "Don't change constant type from int to long")

[commit-bot: I haz the power, 2015-12-11 03:40:59]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1514713002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1514713002/20001

[commit-bot: I haz the power, 2015-12-11 06:08:48]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-12-11 06:10:34]

Description was changed from

==========
Revert "Added a call to ActivityManager.isLowRamDevice() from
SysUtils.detectLowEndDevice()."

This reverts commit 80dc8d87cfd1ef70541c101a355965f3a7a74415.

Some devices in the wild with 1GB of RAM are returning true for
ActivityManager.isLowRamDevice(), causing us to inappropriately enable
aggressive memory optimizations designed for 512MB devices.  Change back
to only considering the true memory capacity of the device.

BUG=568192, 459781
==========

to

==========
Revert "Added a call to ActivityManager.isLowRamDevice() from
SysUtils.detectLowEndDevice()."

This reverts commit 80dc8d87cfd1ef70541c101a355965f3a7a74415.

Some devices in the wild with 1GB of RAM are returning true for
ActivityManager.isLowRamDevice(), causing us to inappropriately enable
aggressive memory optimizations designed for 512MB devices.  Change back
to only considering the true memory capacity of the device.

BUG=568192, 459781

Committed: https://crrev.com/1dc262725270493bf333d53888319acacc5e8baa
Cr-Commit-Position: refs/heads/master@{#364619}
==========

[commit-bot: I haz the power, 2015-12-11 06:10:35]

Patchset 2 (id:??) landed as
https://crrev.com/1dc262725270493bf333d53888319acacc5e8baa
Cr-Commit-Position: refs/heads/master@{#364619}