linux-kernel - 'sar' issue or core dump issue?

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>] [day] [month] [year] [list]

Message-ID: <8db990a81003021207x1c9ed5fav2192f710ec363d06@mail.gmail.com>
Date:	Tue, 2 Mar 2010 14:07:16 -0600
From:	Lizhang Qin <lizhang.qin@...il.com>
To:	linux-kernel@...r.kernel.org
Subject: 'sar' issue or core dump issue?

Hi,

I am experience some performance issue for user space app, when
looking at 'sar' result, it showed things like below.

		          CPU     %user     %nice   %system   %iowait    %steal     %idle
	08:30:02          all      3.29      0.00      9.16      0.01
0.00     87.54
	08:30:12          all      0.38      0.00      2.40      0.38
0.00     96.84
	08:43:39          all      0.28      0.00      1.17      0.87
0.00     97.68

It shows all the records between 08:30:12 to 08:43:39 are missing.
Does it mean kernel actually lose all the statistic data during that
period?  How could that happen though?

I notice there is a big core dump file were written for a crash app
running in the machine.
Could a core dump interfere all the kernel scheduling on all cores (I
have 4 physical CPU adn 8 virtual cores).

Thanks.
--
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/