From: Waiman Long <longman@redhat.com>
To: Thomas Gleixner <tglx@linutronix.de>,
LKML <linux-kernel@vger.kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
Alexey Dobriyan <adobriyan@gmail.com>,
Kees Cook <keescook@chromium.org>,
linux-fsdevel@vger.kernel.org,
Davidlohr Bueso <dave@stgolabs.net>,
Miklos Szeredi <miklos@szeredi.hu>,
Daniel Colascione <dancol@google.com>,
Dave Chinner <david@fromorbit.com>,
Randy Dunlap <rdunlap@infradead.org>,
Marc Zyngier <marc.zyngier@arm.com>
Subject: Re: [patch V2 0/2] genirq, proc: Speedup /proc/stat interrupt statistics
Date: Fri, 8 Feb 2019 10:20:03 -0500 [thread overview]
Message-ID: <43213c22-98fd-c9d4-53a5-21f8ab4fe187@redhat.com> (raw)
In-Reply-To: <20190208134802.218483159@linutronix.de>
On 02/08/2019 08:48 AM, Thomas Gleixner wrote:
> Waiman reported that on large systems with a large amount of interrupts the
> readout of /proc/stat takes a long time to sum up the interrupt
> statistics. In principle this is not a problem. but for unknown reasons
> some enterprise quality software reads /proc/stat with a high frequency.
>
> The reason for this is that interrupt statistics are accounted per cpu. So
> the /proc/stat logic has to sum up the interrupt stats for each interrupt.
>
> The following series addresses this by making the interrupt statitics code
> in the core generate the sum directly and by making the loop in the
> /proc/stat read function smarter.
>
> V1 -> V2: Address review feedback: undo struct layout changes, make
> variables unsigned and add test results to the changelog.
>
> Thanks,
>
> tglx
>
> 8<----------------
> fs/proc/stat.c | 29 ++++++++++++++++++++++++++---
> include/linux/irqdesc.h | 1 +
> kernel/irq/chip.c | 12 ++++++++++--
> kernel/irq/internals.h | 8 +++++++-
> kernel/irq/irqdesc.c | 7 ++++++-
> 5 files changed, 50 insertions(+), 7 deletions(-)
>
Thanks for the patch.
Reviewed-by: Waiman Long <longman@redhat.com>
-Longman
next prev parent reply other threads:[~2019-02-08 15:20 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-08 13:48 [patch V2 0/2] genirq, proc: Speedup /proc/stat interrupt statistics Thomas Gleixner
2019-02-08 13:48 ` [patch V2 1/2] genriq: Avoid summation loops for /proc/stat Thomas Gleixner
2019-02-08 22:32 ` Andrew Morton
2019-02-08 22:46 ` Waiman Long
2019-02-08 23:21 ` Andrew Morton
2019-02-09 3:41 ` Matthew Wilcox
2019-02-13 15:55 ` David Laight
2019-02-08 13:48 ` [patch V2 2/2] proc/stat: Make the interrupt statistics more efficient Thomas Gleixner
2019-02-08 17:01 ` Alexey Dobriyan
2019-02-08 15:20 ` Waiman Long [this message]
2019-02-08 17:01 ` [patch V2 0/2] genirq, proc: Speedup /proc/stat interrupt statistics Davidlohr Bueso
2019-02-08 17:40 ` Marc Zyngier
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