From: Olaf Hering <olaf@aepfle.de>
To: Jan Beulich <jbeulich@suse.com>, Juergen Gross <jgross@suse.com>
Cc: xen-devel@lists.xenproject.org
Subject: Re: xentrace buffer size, maxcpus and online cpus
Date: Fri, 16 Jun 2023 13:47:08 +0200 [thread overview]
Message-ID: <20230616134708.6b3c6964.olaf@aepfle.de> (raw)
In-Reply-To: <1b99e58d-338c-02af-eeab-00d691337d00@suse.com>
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Wed, 31 May 2023 11:05:52 +0200 Jan Beulich <jbeulich@suse.com>:
> As said before, num_online_cpus() will under-report for the purpose
> here, as CPUs may have been brought offline, and may be brought online
> again later (independent of the use of "maxcpus=").
It turned out, commit 74584a367051bc0d6f4b96fd360fa7bc6538fc39 broke
the expected behavior. But to me it is unclear what bug was fixed by
this commit.
If I read alloc_trace_bufs correctly, it already operates on online
cpus. And __trace_var will do nothing if called on a cpu which was
not online, t_bufs will likely be NULL.
To me it looks like commit 74584a367051bc0d6f4b96fd360fa7bc6538fc39
could be reverted.
Olaf
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next prev parent reply other threads:[~2023-06-16 11:47 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-30 7:58 xentrace buffer size, maxcpus and online cpus Olaf Hering
2023-05-30 8:41 ` Jan Beulich
2023-05-30 20:06 ` Olaf Hering
2023-05-31 9:05 ` Jan Beulich
2023-06-16 11:47 ` Olaf Hering [this message]
2023-06-16 11:52 ` Jan Beulich
2023-06-16 14:22 ` George Dunlap
2023-06-16 15:37 ` Olaf Hering
2023-06-16 16:08 ` Andrew Cooper
2023-06-19 10:16 ` Olaf Hering
2023-06-19 11:14 ` Andrew Cooper
2023-06-19 10:13 ` Olaf Hering
2023-06-19 10:22 ` Jan Beulich
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