From: Christoph Hellwig <hch@lst.de>
To: "Michael Kelley (LINUX)" <mikelley@microsoft.com>
Cc: Christoph Hellwig <hch@lst.de>,
"m.szyprowski@samsung.com" <m.szyprowski@samsung.com>,
"robin.murphy@arm.com" <robin.murphy@arm.com>,
Dexuan Cui <decui@microsoft.com>,
Tianyu Lan <Tianyu.Lan@microsoft.com>,
"iommu@lists.linux.dev" <iommu@lists.linux.dev>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v3 1/1] swiotlb: Track and report io_tlb_used high water mark in debugfs
Date: Tue, 11 Apr 2023 05:42:53 +0200 [thread overview]
Message-ID: <20230411034253.GC15679@lst.de> (raw)
In-Reply-To: <BYAPR21MB1688CCCC4CFC597A3C12E370D7969@BYAPR21MB1688.namprd21.prod.outlook.com>
On Fri, Apr 07, 2023 at 10:01:13PM +0000, Michael Kelley (LINUX) wrote:
> I coded the way I did to follow the kernel coding style guidance
> that prefers converting a Kconfig symbol into a C boolean
> expression, and using it in a normal C conditional instead of
> using #ifdef. If CONFIG_DEBUG_FS=n, the compiler will constant
> fold the conditional away so there's no runtime overhead. I
> like the way that approached worked out in this case, but if you prefer
> separate functions with #ifdef and stubs, I don't feel strongly either way.
I don't think there is a a hard and clear rule. Actual ifdefs have the
benefit of allowing to actually remove struct fields as well. But
the important bit is that I do want the accounting in helpers instead
of in the main swiotlb logic. And once you do that, having #ifdefed
stubs for the functions make sense to me.
next prev parent reply other threads:[~2023-04-11 3:42 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-01 4:45 [PATCH v3 1/1] swiotlb: Track and report io_tlb_used high water mark in debugfs Michael Kelley
2023-04-07 5:50 ` Christoph Hellwig
2023-04-07 22:01 ` Michael Kelley (LINUX)
2023-04-11 3:42 ` Christoph Hellwig [this message]
2023-04-07 10:55 ` Petr Tesařík
2023-04-07 22:05 ` Michael Kelley (LINUX)
2023-04-11 3:41 ` hch
2023-04-12 17:30 ` Michael Kelley (LINUX)
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=20230411034253.GC15679@lst.de \
--to=hch@lst.de \
--cc=Tianyu.Lan@microsoft.com \
--cc=decui@microsoft.com \
--cc=iommu@lists.linux.dev \
--cc=linux-kernel@vger.kernel.org \
--cc=m.szyprowski@samsung.com \
--cc=mikelley@microsoft.com \
--cc=robin.murphy@arm.com \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.