Revert of tcmalloc: Use futex syscall in SpinLockDelay() for ARM.

Revert of tcmalloc: Use futex syscall in SpinLockDelay() for ARM. (patchset #5 id:80001 of https://codereview.chromium.org/2457473003/ )

Reason for revert:
It seems that a ChromeOS build with clang has failed, details on: https://bugs.chromium.org/p/chromium/issues/detail?id=666839

We will revert the patch while the issue is being investigated.

Original issue's description:
> tcmalloc: Use futex syscall in SpinLockDelay() for ARM.
>
> SpinLockDelay() was avoiding using futex() when compiled for ARM.
> The alternative implementation was sleeping for 2 ms. This caused
> performance issues in Telemetry's SvgCubics benchmark. The score for
> this benchmark more than doubles when this patch is applied (scores were
> measured on veyron_jerry, veyron_minnie, daisy). Other benchmarks
> (blink_perf.bindings/post-message, blink_perf.canvas/draw-static-webgl-
> to-hw-accelerated-canvas-2d) benefit from this change to a lesser
> extent. This patch also removes a reference to futex1 in a comment in
> linux-syscall_support.h, as this is not a valid syscall name.
>
> Note that a similar fix was pushed in the upstream version of tcmalloc
> (issue-693, https://github.com/gperftools/gperftools/commit/7df7f14).
>
> BUG=
>
> Change-Id: I390ac51ed5e1b0ad021ac63eaf3bce81cdca8599
> Committed: https://crrev.com/7f1336053e39737671a52ca7a265007e9024ee8a
> Cr-Commit-Position: refs/heads/master@{#432628}

TBR=wfh@chromium.org,thakis@chromium.org,primiano@chromium.org,matteo.franchin@arm.com
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=

Committed: https://crrev.com/91996d7dd9c5cb939e40cf33e300fd0b3dace5fb
Cr-Commit-Position: refs/heads/master@{#433305}

[cavalcantii1, 2016-11-18 20:59:48]

The CQ bit was checked by cavalcantii@chromium.org

[cavalcantii1, 2016-11-18 20:59:49]

Created Revert of tcmalloc: Use futex syscall in SpinLockDelay() for ARM.

[commit-bot: I haz the power, 2016-11-18 21:00:29]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-18 21:44:13]

Description was changed from

==========
Revert of tcmalloc: Use futex syscall in SpinLockDelay() for ARM. (patchset #5
id:80001 of https://codereview.chromium.org/2457473003/ )

Reason for revert:
It seems that a ChromeOS build with clang has failed, details on:
https://bugs.chromium.org/p/chromium/issues/detail?id=666839

We will revert the patch while the issue is being investigated.

Original issue's description:
> tcmalloc: Use futex syscall in SpinLockDelay() for ARM.
> 
> SpinLockDelay() was avoiding using futex() when compiled for ARM.
> The alternative implementation was sleeping for 2 ms. This caused
> performance issues in Telemetry's SvgCubics benchmark. The score for
> this benchmark more than doubles when this patch is applied (scores were
> measured on veyron_jerry, veyron_minnie, daisy). Other benchmarks
> (blink_perf.bindings/post-message, blink_perf.canvas/draw-static-webgl-
> to-hw-accelerated-canvas-2d) benefit from this change to a lesser
> extent. This patch also removes a reference to futex1 in a comment in
> linux-syscall_support.h, as this is not a valid syscall name.
> 
> Note that a similar fix was pushed in the upstream version of tcmalloc
> (issue-693, https://github.com/gperftools/gperftools/commit/7df7f14).
> 
> BUG=
> 
> Change-Id: I390ac51ed5e1b0ad021ac63eaf3bce81cdca8599
> Committed: https://crrev.com/7f1336053e39737671a52ca7a265007e9024ee8a
> Cr-Commit-Position: refs/heads/master@{#432628}

TBR=wfh@chromium.org,thakis@chromium.org,primiano@chromium.org,matteo.franchi...
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=
==========

to

==========
Revert of tcmalloc: Use futex syscall in SpinLockDelay() for ARM. (patchset #5
id:80001 of https://codereview.chromium.org/2457473003/ )

Reason for revert:
It seems that a ChromeOS build with clang has failed, details on:
https://bugs.chromium.org/p/chromium/issues/detail?id=666839

We will revert the patch while the issue is being investigated.

Original issue's description:
> tcmalloc: Use futex syscall in SpinLockDelay() for ARM.
> 
> SpinLockDelay() was avoiding using futex() when compiled for ARM.
> The alternative implementation was sleeping for 2 ms. This caused
> performance issues in Telemetry's SvgCubics benchmark. The score for
> this benchmark more than doubles when this patch is applied (scores were
> measured on veyron_jerry, veyron_minnie, daisy). Other benchmarks
> (blink_perf.bindings/post-message, blink_perf.canvas/draw-static-webgl-
> to-hw-accelerated-canvas-2d) benefit from this change to a lesser
> extent. This patch also removes a reference to futex1 in a comment in
> linux-syscall_support.h, as this is not a valid syscall name.
> 
> Note that a similar fix was pushed in the upstream version of tcmalloc
> (issue-693, https://github.com/gperftools/gperftools/commit/7df7f14).
> 
> BUG=
> 
> Change-Id: I390ac51ed5e1b0ad021ac63eaf3bce81cdca8599
> Committed: https://crrev.com/7f1336053e39737671a52ca7a265007e9024ee8a
> Cr-Commit-Position: refs/heads/master@{#432628}

TBR=wfh@chromium.org,thakis@chromium.org,primiano@chromium.org,matteo.franchi...
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=
==========

[commit-bot: I haz the power, 2016-11-18 21:44:13]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-11-18 21:48:29]

Description was changed from

==========
Revert of tcmalloc: Use futex syscall in SpinLockDelay() for ARM. (patchset #5
id:80001 of https://codereview.chromium.org/2457473003/ )

Reason for revert:
It seems that a ChromeOS build with clang has failed, details on:
https://bugs.chromium.org/p/chromium/issues/detail?id=666839

We will revert the patch while the issue is being investigated.

Original issue's description:
> tcmalloc: Use futex syscall in SpinLockDelay() for ARM.
> 
> SpinLockDelay() was avoiding using futex() when compiled for ARM.
> The alternative implementation was sleeping for 2 ms. This caused
> performance issues in Telemetry's SvgCubics benchmark. The score for
> this benchmark more than doubles when this patch is applied (scores were
> measured on veyron_jerry, veyron_minnie, daisy). Other benchmarks
> (blink_perf.bindings/post-message, blink_perf.canvas/draw-static-webgl-
> to-hw-accelerated-canvas-2d) benefit from this change to a lesser
> extent. This patch also removes a reference to futex1 in a comment in
> linux-syscall_support.h, as this is not a valid syscall name.
> 
> Note that a similar fix was pushed in the upstream version of tcmalloc
> (issue-693, https://github.com/gperftools/gperftools/commit/7df7f14).
> 
> BUG=
> 
> Change-Id: I390ac51ed5e1b0ad021ac63eaf3bce81cdca8599
> Committed: https://crrev.com/7f1336053e39737671a52ca7a265007e9024ee8a
> Cr-Commit-Position: refs/heads/master@{#432628}

TBR=wfh@chromium.org,thakis@chromium.org,primiano@chromium.org,matteo.franchi...
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=
==========

to

==========
Revert of tcmalloc: Use futex syscall in SpinLockDelay() for ARM. (patchset #5
id:80001 of https://codereview.chromium.org/2457473003/ )

Reason for revert:
It seems that a ChromeOS build with clang has failed, details on:
https://bugs.chromium.org/p/chromium/issues/detail?id=666839

We will revert the patch while the issue is being investigated.

Original issue's description:
> tcmalloc: Use futex syscall in SpinLockDelay() for ARM.
>
> SpinLockDelay() was avoiding using futex() when compiled for ARM.
> The alternative implementation was sleeping for 2 ms. This caused
> performance issues in Telemetry's SvgCubics benchmark. The score for
> this benchmark more than doubles when this patch is applied (scores were
> measured on veyron_jerry, veyron_minnie, daisy). Other benchmarks
> (blink_perf.bindings/post-message, blink_perf.canvas/draw-static-webgl-
> to-hw-accelerated-canvas-2d) benefit from this change to a lesser
> extent. This patch also removes a reference to futex1 in a comment in
> linux-syscall_support.h, as this is not a valid syscall name.
>
> Note that a similar fix was pushed in the upstream version of tcmalloc
> (issue-693, https://github.com/gperftools/gperftools/commit/7df7f14).
>
> BUG=
>
> Change-Id: I390ac51ed5e1b0ad021ac63eaf3bce81cdca8599
> Committed: https://crrev.com/7f1336053e39737671a52ca7a265007e9024ee8a
> Cr-Commit-Position: refs/heads/master@{#432628}

TBR=wfh@chromium.org,thakis@chromium.org,primiano@chromium.org,matteo.franchi...
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=

Committed: https://crrev.com/91996d7dd9c5cb939e40cf33e300fd0b3dace5fb
Cr-Commit-Position: refs/heads/master@{#433305}
==========

[commit-bot: I haz the power, 2016-11-18 21:48:30]

Patchset 1 (id:??) landed as
https://crrev.com/91996d7dd9c5cb939e40cf33e300fd0b3dace5fb
Cr-Commit-Position: refs/heads/master@{#433305}