From: Andi Kleen <ak@muc.de>
To: Ingo Oeser <ingo.oeser@informatik.tu-chemnitz.de>
Cc: Andrea Arcangeli <andrea@suse.de>,
Rik van Riel <riel@nl.linux.org>,
Linux Kernel <linux-kernel@vger.rutgers.edu>,
Linux MM <linux-mm@kvack.org>
Subject: Re: GFP_XXX semantics (was: Re: [PATCH] 2.2.1{3,4,5} VM fix)
Date: Mon, 24 Jan 2000 14:40:51 +0100 [thread overview]
Message-ID: <20000124144051.A1340@fred.muc.de> (raw)
In-Reply-To: <Pine.LNX.4.10.10001241411310.24852-100000@nightmaster.csn. tu-chemnitz.de>; from Ingo Oeser on Mon, Jan 24, 2000 at 02:22:45PM +0100
On Mon, Jan 24, 2000 at 02:22:45PM +0100, Ingo Oeser wrote:
> On Sat, 22 Jan 2000, Andrea Arcangeli wrote:
>
> [GFP-Mask semantics discussion]
>
> ok, once we are about it here, could you please explain the
> _exact_ semantics for the GFP_XXX constants?
>
> GFP_BUFFER
> GFP_ATOMIC
> GFP_BIGUSER
> GFP_USER
> GFP_KERNEL
> GFP_NFS
> GFP_KSWAPD
>
> So which steps are tried to allocate these pages (freeing
> process, freeing globally, waiting, failing, kswapd-wakeup)?
>
> Because it is not easy to decide from a driver writers point of
> view, which one to use for which requests :(
As device driver writer you should only use two:
GFP_ATOMIC in interrupts/bottom halves/when you cannot sleep and
GFP_KERNEL when you're in user context and able to sleep.
All others are internal and only used by specific subsystems you
shouldn't care about.
-Andi
--
This is like TV. I don't like TV.
--
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.eu.org/Linux-MM/
next prev parent reply other threads:[~2000-01-24 13:40 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2000-01-19 21:15 [PATCH] 2.2.1{3,4,5} VM fix Rik van Riel
2000-01-20 17:11 ` Andrea Arcangeli
2000-01-20 20:30 ` Rik van Riel
2000-01-21 0:42 ` Andrea Arcangeli
2000-01-21 0:56 ` Alan Cox
2000-01-21 2:08 ` Andrea Arcangeli
2000-01-21 2:43 ` Rik van Riel
2000-01-21 12:54 ` Andrea Arcangeli
2000-01-21 19:18 ` Rik van Riel
2000-01-22 2:43 ` Andrea Arcangeli
2000-01-22 3:22 ` Benjamin C.R. LaHaise
2000-01-22 14:02 ` Andrea Arcangeli
2000-01-24 13:21 ` GFP_XXX semantics (was: Re: [PATCH] 2.2.1{3,4,5} VM fix) Ingo Oeser
2000-01-24 15:08 ` Andrea Arcangeli
2000-01-25 0:01 ` Rik van Riel
[not found] ` <Pine.LNX.4.10.10001241411310.24852-100000@nightmaster.csn. tu-chemnitz.de>
2000-01-24 13:40 ` Andi Kleen [this message]
2000-01-21 1:12 ` [PATCH] 2.2.1{3,4,5} VM fix Rik van Riel
2000-01-21 2:01 ` Andrea Arcangeli
2000-01-21 2:36 ` Andrea Arcangeli
2000-01-21 2:37 ` Rik van Riel
2000-01-21 13:24 ` Andrea Arcangeli
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=20000124144051.A1340@fred.muc.de \
--to=ak@muc.de \
--cc=andrea@suse.de \
--cc=ingo.oeser@informatik.tu-chemnitz.de \
--cc=linux-kernel@vger.rutgers.edu \
--cc=linux-mm@kvack.org \
--cc=riel@nl.linux.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