All of lore.kernel.org
 help / color / mirror / Atom feed
From: Ingo Molnar <mingo@kernel.org>
To: Toshi Kani <toshi.kani@hp.com>
Cc: akpm@linux-foundation.org, hpa@zytor.com, tglx@linutronix.de,
	mingo@redhat.com, arnd@arndb.de, linux-mm@kvack.org,
	x86@kernel.org, linux-kernel@vger.kernel.org, Elliott@hp.com
Subject: Re: [PATCH v2 6/7] x86, mm: Support huge I/O mappings on x86
Date: Wed, 18 Feb 2015 21:44:14 +0100	[thread overview]
Message-ID: <20150218204414.GA20943@gmail.com> (raw)
In-Reply-To: <1423521935-17454-7-git-send-email-toshi.kani@hp.com>


* Toshi Kani <toshi.kani@hp.com> wrote:

> This patch implements huge I/O mapping capability interfaces on x86.

> +#ifdef CONFIG_HUGE_IOMAP
> +#ifdef CONFIG_X86_64
> +#define IOREMAP_MAX_ORDER       (PUD_SHIFT)
> +#else
> +#define IOREMAP_MAX_ORDER       (PMD_SHIFT)
> +#endif
> +#endif  /* CONFIG_HUGE_IOMAP */

> +#ifdef CONFIG_HUGE_IOMAP

Hm, so why is there a Kconfig option for this? It just 
complicates things.

For example the kernel already defaults to mapping itself 
with as large mappings as possible, without a Kconfig entry 
for it. There's no reason to make this configurable - and 
quite a bit of complexity in the patches comes from this 
configurability.

Thanks,

	Ingo

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

WARNING: multiple messages have this Message-ID (diff)
From: Ingo Molnar <mingo@kernel.org>
To: Toshi Kani <toshi.kani@hp.com>
Cc: akpm@linux-foundation.org, hpa@zytor.com, tglx@linutronix.de,
	mingo@redhat.com, arnd@arndb.de, linux-mm@kvack.org,
	x86@kernel.org, linux-kernel@vger.kernel.org, Elliott@hp.com
Subject: Re: [PATCH v2 6/7] x86, mm: Support huge I/O mappings on x86
Date: Wed, 18 Feb 2015 21:44:14 +0100	[thread overview]
Message-ID: <20150218204414.GA20943@gmail.com> (raw)
In-Reply-To: <1423521935-17454-7-git-send-email-toshi.kani@hp.com>


* Toshi Kani <toshi.kani@hp.com> wrote:

> This patch implements huge I/O mapping capability interfaces on x86.

> +#ifdef CONFIG_HUGE_IOMAP
> +#ifdef CONFIG_X86_64
> +#define IOREMAP_MAX_ORDER       (PUD_SHIFT)
> +#else
> +#define IOREMAP_MAX_ORDER       (PMD_SHIFT)
> +#endif
> +#endif  /* CONFIG_HUGE_IOMAP */

> +#ifdef CONFIG_HUGE_IOMAP

Hm, so why is there a Kconfig option for this? It just 
complicates things.

For example the kernel already defaults to mapping itself 
with as large mappings as possible, without a Kconfig entry 
for it. There's no reason to make this configurable - and 
quite a bit of complexity in the patches comes from this 
configurability.

Thanks,

	Ingo

  reply	other threads:[~2015-02-18 20:44 UTC|newest]

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-02-09 22:45 [PATCH v2 0/7] Kernel huge I/O mapping support Toshi Kani
2015-02-09 22:45 ` Toshi Kani
2015-02-09 22:45 ` [PATCH v2 1/7] mm: Change __get_vm_area_node() to use fls_long() Toshi Kani
2015-02-09 22:45   ` Toshi Kani
2015-02-09 22:45 ` [PATCH v2 2/7] lib: Add huge I/O map capability interfaces Toshi Kani
2015-02-09 22:45   ` Toshi Kani
2015-02-09 22:45 ` [PATCH v2 3/7] mm: Change ioremap to set up huge I/O mappings Toshi Kani
2015-02-09 22:45   ` Toshi Kani
2015-02-09 22:45 ` [PATCH v2 4/7] mm: Change vunmap to tear down huge KVA mappings Toshi Kani
2015-02-09 22:45   ` Toshi Kani
2015-02-09 22:45 ` [PATCH v2 5/7] x86, mm: Support huge KVA mappings on x86 Toshi Kani
2015-02-09 22:45   ` Toshi Kani
2015-02-10 18:59   ` Dave Hansen
2015-02-10 18:59     ` Dave Hansen
2015-02-10 20:42     ` Toshi Kani
2015-02-10 20:42       ` Toshi Kani
2015-02-10 20:51       ` Dave Hansen
2015-02-10 20:51         ` Dave Hansen
2015-02-10 22:13         ` Toshi Kani
2015-02-10 22:13           ` Toshi Kani
2015-02-10 22:20           ` Toshi Kani
2015-02-10 22:20             ` Toshi Kani
2015-02-10 23:10           ` Toshi Kani
2015-02-10 23:10             ` Toshi Kani
2015-03-03  0:37             ` Toshi Kani
2015-03-03  0:37               ` Toshi Kani
2015-02-09 22:45 ` [PATCH v2 6/7] x86, mm: Support huge I/O " Toshi Kani
2015-02-09 22:45   ` Toshi Kani
2015-02-18 20:44   ` Ingo Molnar [this message]
2015-02-18 20:44     ` Ingo Molnar
2015-02-18 21:13     ` Toshi Kani
2015-02-18 21:13       ` Toshi Kani
2015-02-18 21:15       ` Ingo Molnar
2015-02-18 21:15         ` Ingo Molnar
2015-02-18 21:33         ` Toshi Kani
2015-02-18 21:33           ` Toshi Kani
2015-02-18 21:57           ` Ingo Molnar
2015-02-18 21:57             ` Ingo Molnar
2015-02-18 22:14             ` Toshi Kani
2015-02-18 22:14               ` Toshi Kani
2015-02-09 22:45 ` [PATCH v2 7/7] mm: Add config HUGE_IOMAP to enable huge I/O mappings Toshi Kani
2015-02-09 22:45   ` Toshi Kani
2015-02-23 20:22 ` [PATCH v2 0/7] Kernel huge I/O mapping support Andrew Morton
2015-02-23 20:22   ` Andrew Morton
2015-02-23 23:54   ` Toshi Kani
2015-02-23 23:54     ` Toshi Kani
2015-02-24  8:09   ` Ingo Molnar
2015-02-24  8:09     ` Ingo Molnar
2015-03-02 15:51     ` Toshi Kani
2015-03-02 15:51       ` Toshi Kani

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=20150218204414.GA20943@gmail.com \
    --to=mingo@kernel.org \
    --cc=Elliott@hp.com \
    --cc=akpm@linux-foundation.org \
    --cc=arnd@arndb.de \
    --cc=hpa@zytor.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mingo@redhat.com \
    --cc=tglx@linutronix.de \
    --cc=toshi.kani@hp.com \
    --cc=x86@kernel.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 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.