linux-kernel - Re: [PATCH] perf record: mmap output file

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20131009133331.GC5459@krava.redhat.com>
Date:	Wed, 9 Oct 2013 15:33:31 +0200
From:	Jiri Olsa <jolsa@...hat.com>
To:	David Ahern <dsahern@...il.com>
Cc:	acme@...stprotocols.net, linux-kernel@...r.kernel.org,
	Ingo Molnar <mingo@...nel.org>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Namhyung Kim <namhyung@...nel.org>,
	Mike Galbraith <efault@....de>,
	Stephane Eranian <eranian@...gle.com>
Subject: Re: [PATCH] perf record: mmap output file - RFC

On Sun, Sep 22, 2013 at 08:05:59PM -0600, David Ahern wrote:

SNIP

> +
> +	if (size > remaining) {
> +		memcpy(rec->mmap_addr + rec->mmap_offset, buf, remaining);
> +		rec->bytes_written += remaining;
> +
> +		size -= remaining;
> +		buf  += remaining;
> +
> +		msync(rec->mmap_addr, rec->mmap_size, MS_ASYNC);
> +		munmap(rec->mmap_addr, rec->mmap_size);

do we need msync call if munmap is called right away?


> +		goto do_mmap;

SNIP

> +	if (rec->use_mmap) {
> +		off_t len = rec->bytes_at_mmap_start + rec->bytes_written;
> +
> +		rec->use_mmap = false;
> +		msync(rec->mmap_addr, rec->mmap_size, MS_ASYNC);
> +		munmap(rec->mmap_addr, rec->mmap_size);

ditto

thanks,
jirka
--
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/