linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: sboyd@codeaurora.org (Stephen Boyd)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 2/2] ARM: Enable tracing around vfp preemption enable/disable
Date: Mon,  4 Mar 2013 14:43:03 -0800	[thread overview]
Message-ID: <1362436983-28988-3-git-send-email-sboyd@codeaurora.org> (raw)
In-Reply-To: <1362436983-28988-1-git-send-email-sboyd@codeaurora.org>

The VFP code enables and disables preemption but doesn't call
into the tracer except for in the VFP bounce code to say that
preemption has been enabled again. Trace the preemption disable
and enable calls made in assembly so that we can accurately
measure how long preemption is disabled while handling VFP
exceptions.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
---
 arch/arm/kernel/entry-header.S | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index 130e6a6..75bcb18 100644
--- a/arch/arm/kernel/entry-header.S
+++ b/arch/arm/kernel/entry-header.S
@@ -165,19 +165,33 @@
 
 	.macro preempt_enable_no_resched, tsk, cnt
 #ifdef CONFIG_PREEMPT_COUNT
+#if defined(CONFIG_DEBUG_PREEMPT) || defined(CONFIG_PREEMPT_TRACER)
+	stmdb   sp!, {r0-r3, ip, lr}
+	mov	r0, #1
+	bl	sub_preempt_count
+	ldmia	sp!, {r0-r3, ip, lr}
+#else
 	get_thread_info	\tsk
 	ldr	\cnt, [\tsk, #TI_PREEMPT]	@ get preempt count
 	sub	\cnt, \cnt, #1			@ decrement it
 	str	\cnt, [\tsk, #TI_PREEMPT]
 #endif
+#endif
 	.endm
 
 	.macro preempt_disable, tsk, cnt
 #ifdef CONFIG_PREEMPT_COUNT
+#if defined(CONFIG_DEBUG_PREEMPT) || defined(CONFIG_PREEMPT_TRACER)
+	stmdb   sp!, {r0-r3, ip, lr}
+	mov	r0, #1
+	bl	add_preempt_count
+	ldmia	sp!, {r0-r3, ip, lr}
+#else
 	ldr	\cnt, [\tsk, #TI_PREEMPT]	@ get preempt count
 	add	\cnt, \cnt, #1			@ increment it
 	str	\cnt, [\tsk, #TI_PREEMPT]
 #endif
+#endif
 	.endm
 
 /*
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by The Linux Foundation

      parent reply	other threads:[~2013-03-04 22:43 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-03-04 22:43 [PATCH 0/2] Call tracing/debug code in VFP preempt code Stephen Boyd
2013-03-04 22:43 ` [PATCH 1/2] ARM: Consolidate preempt enable/disable assembly into macros Stephen Boyd
2013-03-04 22:43 ` Stephen Boyd [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1362436983-28988-3-git-send-email-sboyd@codeaurora.org \
    --to=sboyd@codeaurora.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).