From: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
To: Michael Neuling <mikey@neuling.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>,
linux-kernel@vger.kernel.org, npiggin@gmail.com,
paulus@samba.org, naveen.n.rao@linux.vnet.ibm.com,
linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH 4/5] Powerpc/hw-breakpoint: Optimize disable path
Date: Wed, 19 Jun 2019 11:32:28 +0530 [thread overview]
Message-ID: <c4efb3e1-acb7-df2a-513d-02004d487cae@linux.ibm.com> (raw)
In-Reply-To: <ab7e5fac2a1ea78181900f5df7411b1f51b65eb9.camel@neuling.org>
On 6/18/19 11:45 AM, Michael Neuling wrote:
> On Tue, 2019-06-18 at 09:57 +0530, Ravi Bangoria wrote:
>> Directly setting dawr and dawrx with 0 should be enough to
>> disable watchpoint. No need to reset individual bits in
>> variable and then set in hw.
>
> This seems like a pointless optimisation to me.
>
> I'm all for adding more code/complexity if it buys us some performance, but I
> can't imagine this is a fast path (nor have you stated any performance
> benefits).
This gets called from sched_switch. I expected the improvement when
we switch from monitored process to non-monitored process. With such
scenario, I tried to measure the difference in execution time of
set_dawr but I don't see any improvement. So I'll drop the patch.
next prev parent reply other threads:[~2019-06-19 6:04 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-18 4:27 [PATCH 0/5] Powerpc/hw-breakpoint: Fixes plus Code refactor Ravi Bangoria
2019-06-18 4:27 ` [PATCH 1/5] Powerpc/hw-breakpoint: Replace stale do_dabr() with do_break() Ravi Bangoria
2019-06-18 6:02 ` Michael Neuling
2019-06-18 6:14 ` Christophe Leroy
2019-06-18 4:27 ` [PATCH 2/5] Powerpc/hw-breakpoint: Refactor hw_breakpoint_arch_parse() Ravi Bangoria
2019-06-18 6:21 ` Christophe Leroy
2019-06-18 7:10 ` Ravi Bangoria
2019-06-18 4:27 ` [PATCH 3/5] Powerpc/hw-breakpoint: Refactor set_dawr() Ravi Bangoria
2019-06-18 6:11 ` Michael Neuling
2019-06-18 7:13 ` Ravi Bangoria
2019-06-18 6:24 ` Christophe Leroy
2019-06-18 4:27 ` [PATCH 4/5] Powerpc/hw-breakpoint: Optimize disable path Ravi Bangoria
2019-06-18 6:15 ` Michael Neuling
2019-06-19 6:02 ` Ravi Bangoria [this message]
2019-06-18 6:31 ` Christophe Leroy
2019-06-19 6:14 ` Ravi Bangoria
2019-06-18 4:27 ` [PATCH 5/5] Powerpc/Watchpoint: Fix length calculation for unaligned target Ravi Bangoria
2019-06-18 6:46 ` Christophe Leroy
2019-06-19 6:51 ` Ravi Bangoria
2019-06-18 13:32 ` Michael Neuling
2019-06-19 7:45 ` Ravi Bangoria
2019-06-18 6:01 ` [PATCH 0/5] Powerpc/hw-breakpoint: Fixes plus Code refactor Christophe Leroy
2019-06-18 6:17 ` Michael Neuling
2019-06-19 7:47 ` Ravi Bangoria
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=c4efb3e1-acb7-df2a-513d-02004d487cae@linux.ibm.com \
--to=ravi.bangoria@linux.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=mikey@neuling.org \
--cc=naveen.n.rao@linux.vnet.ibm.com \
--cc=npiggin@gmail.com \
--cc=paulus@samba.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).