From: Peter Zijlstra <peterz@infradead.org>
To: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86/mm: Simplify RESERVE_BRK()
Date: Fri, 29 Apr 2022 12:10:03 +0200 [thread overview]
Message-ID: <Ymu5e24d3JRWJdHb@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <0e001c79794c46d619714d122c262147ed83f658.1651176151.git.jpoimboe@redhat.com>
On Thu, Apr 28, 2022 at 01:04:25PM -0700, Josh Poimboeuf wrote:
> RESERVE_BRK() reserves data in the .brk_reservation section. The data
> is initialized to zero, like BSS, so the macro specifies 'nobits' to
> prevent the data from taking up space in the vmlinux binary. The only
> way to get the compiler to do that (without putting the variable in .bss
> proper) is to use inline asm.
>
> The macro also has a hack which encloses the inline asm in a discarded
> function, which allows the size to be passed (global inline asm doesn't
> allow inputs).
>
> Remove the need for the discarded function hack by just stringifying the
> size rather than supplying it as an input to the inline asm.
>
> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
next prev parent reply other threads:[~2022-04-29 10:10 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-28 20:04 Josh Poimboeuf
2022-04-29 10:10 ` Peter Zijlstra [this message]
2022-05-04 10:03 ` Borislav Petkov
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=Ymu5e24d3JRWJdHb@hirez.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=jpoimboe@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®