linux-kernel - Re: [PATCH 3/3] KVM: perf: kvm events analysis tool

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

Date:	Mon, 20 Feb 2012 21:58:29 -0700
From:	David Ahern <dsahern@...il.com>
To:	Xiao Guangrong <xiaoguangrong@...ux.vnet.ibm.com>
CC:	Arnaldo Carvalho de Melo <acme@...radead.org>,
	Avi Kivity <avi@...hat.com>,
	Marcelo Tosatti <mtosatti@...hat.com>,
	Ingo Molnar <mingo@...e.hu>,
	LKML <linux-kernel@...r.kernel.org>, KVM <kvm@...r.kernel.org>
Subject: Re: [PATCH 3/3] KVM: perf: kvm events analysis tool

On 2/20/12 8:52 PM, Xiao Guangrong wrote:
>>> +    /* Both begin and end events did not get the key. */
>>> +    if (!event&&   key->key == INVALID_KEY)
>>> +        return;
>>> +
>> Should not be able to get here with event unset, so the next 2 lines should not be needed. ie., you only want to process events where the begin event was seen in which case event is defined.
>
>
> In some case, the 'begin event' just records the start timestamp, the actually event
> is recognised in the 'end event'.
>
> Take mmio-read for example, in the old kernel, we use kvm-exit as the 'begin event'
> and kvm_mmio(KVM_TRACE_MMIO_READ...) is the 'end event'.

ah, ok. Please add a comment about this path.

David

--
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/