linux-kernel - Re: [PATCH 07/15] mm: Add ___GFP

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20150302143319.4ae86674@gandalf.local.home>
Date:	Mon, 2 Mar 2015 14:33:19 -0500
From:	Steven Rostedt <rostedt@...dmis.org>
To:	Alexei Starovoitov <ast@...mgrid.com>
Cc:	Tom Zanussi <tom.zanussi@...ux.intel.com>,
	Masami Hiramatsu <masami.hiramatsu.pt@...achi.com>,
	Namhyung Kim <namhyung@...nel.org>,
	Andi Kleen <andi@...stfloor.org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 07/15] mm: Add ___GFP_NOTRACE

On Mon, 2 Mar 2015 11:24:04 -0800
Alexei Starovoitov <ast@...mgrid.com> wrote:
 
> well, percentage of tracepoints called from NMI is tiny
> comparing to the rest, so assuming nmi context
> everywhere is very inefficient.
> Like we can use pre-allocated pool of map entries when
> tracepoint is called from NMI, but we shouldn't be using
> it in other cases. Just like ring buffers and other things
> have nmi and non-nmi pools and code paths, it doesn't
> make sense to disallow kmalloc all together.
> btw, calling kmalloc is _faster_ than taking
> objects from cache-cold special nmi only pool.

Please show the numbers and post the tests when stating something like
that.

-- Steve

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/