From: Peter Zijlstra <peterz@infradead.org>
To: Manikandan Jagatheesan <mjagatheesan@vmware.com>
Cc: "bp@suse.de" <bp@suse.de>,
"jpoimboe@kernel.org" <jpoimboe@kernel.org>,
"tglx@linutronix.de" <tglx@linutronix.de>,
"mingo@redhat.com" <mingo@redhat.com>,
"bp@alien8.de" <bp@alien8.de>,
"dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>,
"x86@kernel.org" <x86@kernel.org>,
"hpa@zytor.com" <hpa@zytor.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"srivatsa@csail.mit.edu" <srivatsa@csail.mit.edu>,
Peter Jonasson <pjonasson@vmware.com>,
Yiu Cho Lau <lauyiuch@vmware.com>, Rajender M <manir@vmware.com>,
Abdul Anshad Azeez <aazees@vmware.com>,
Kodeswaran Kumarasamy <kkumarasamy@vmware.com>,
Rahul Gopakumar <gopakumarr@vmware.com>
Subject: Re: Performance Regression in Linux Kernel 5.19
Date: Fri, 9 Sep 2022 15:18:40 +0200 [thread overview]
Message-ID: <Yxs9MGGmSShJGaXs@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <PH0PR05MB8448A203A909959FAC754B7AAF439@PH0PR05MB8448.namprd05.prod.outlook.com>
On Fri, Sep 09, 2022 at 11:46:08AM +0000, Manikandan Jagatheesan wrote:
> As part of VMware's performance regression testing for Linux
> Kernel upstream releases, we have evaluated the performance
> of Linux kernel 5.19 against the 5.18 release and we have
> noticed performance regressions in Linux VMs on ESXi as shown
> below.
> - Compute(up to -70%)
> - Networking(up to -30%)
> - Storage(up to -13%)
>
> After performing the bisect between kernel 5.18 and 5.19, we
> identified the root cause to be the enablement of IBRS mitigation
> for spectre_v2 vulnerability by commit 6ad0ad2bf8a6 ("x86/bugs:
> Report Intel retbleed vulnerability").
>
> To confirm this, we have disabled the above security mitigation
> through kernel boot parameter(spectre_v2=off) in 5.19 and re-ran
> our tests & confirmed that the performance was on-par with
> 5.18 release.
Well, duh.. :-)
next prev parent reply other threads:[~2022-09-09 13:19 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-09 11:46 Performance Regression in Linux Kernel 5.19 Manikandan Jagatheesan
2022-09-09 13:18 ` Peter Zijlstra [this message]
2022-09-09 21:22 ` David Laight
2022-09-10 7:52 ` Borislav Petkov
2022-09-12 10:58 ` Borislav Petkov
2022-09-13 8:40 ` Manikandan Jagatheesan
2022-09-13 10:27 ` Boris Petkov
2022-09-13 11:20 ` Peter Zijlstra
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