All of lore.kernel.org
 help / color / mirror / Atom feed
From: Boris Ostrovsky <boris.ostrovsky@oracle.com>
To: Jan Beulich <JBeulich@suse.com>
Cc: tim@xen.org, kevin.tian@intel.com, keir@xen.org,
	suravee.suthikulpanit@amd.com, andrew.cooper3@citrix.com,
	eddie.dong@intel.com, xen-devel@lists.xen.org,
	Aravind.Gopalakrishnan@amd.com, jun.nakajima@intel.com
Subject: Re: [PATCH v10 11/20] x86/VPMU: Interface for setting PMU mode and flags
Date: Fri, 12 Sep 2014 11:54:41 -0400	[thread overview]
Message-ID: <54131741.90407@oracle.com> (raw)
In-Reply-To: <54132DA5020000780003493C@mail.emea.novell.com>

On 09/12/2014 11:30 AM, Jan Beulich wrote:
>>>> On 12.09.14 at 17:03, <boris.ostrovsky@oracle.com> wrote:
>> My concern is that on a very large system we may be getting lots of
>> preemptions and thus this will be failing for the sysadmin somewhat
>> often and without clear reason. (I am basing this assumption on the fact
>> that I am currently looking at a ~200CPU box with gobs of memory and
>> some operations that use contuations get preempted very often. Hundreds
>> of times. I don't remember seeing this on "regular" systems).
> Yeah, quite likely due to IPI counts growing approximately with the
> square of the CPU count.
>
> We've been considering adding a "minimum amount of progress"
> mechanism to various places where preemption can (at least under
> some conditions) be observed on every iteration. Perhaps along
> with having the 5s timeout you also want a minimum amount of
> time during which you don't check for preemption (yet)?

Yes, I can do that. Something like half second?

This is a very infrequent operation that can only be done in dom0 by a 
sysadmin so even if this seems a bit too long I think it's safe enough.

-boris

  reply	other threads:[~2014-09-12 15:54 UTC|newest]

Thread overview: 72+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-09-04  3:41 [PATCH v10 00/20] x86/PMU: Xen PMU PV(H) support Boris Ostrovsky
2014-09-04  3:41 ` [PATCH v10 01/20] common/symbols: Export hypervisor symbols to privileged guest Boris Ostrovsky
2014-09-04  3:41 ` [PATCH v10 02/20] x86/VPMU: Manage VPMU_CONTEXT_SAVE flag in vpmu_save_force() Boris Ostrovsky
2014-09-04  3:41 ` [PATCH v10 03/20] x86/VPMU: Set MSR bitmaps only for HVM/PVH guests Boris Ostrovsky
2014-09-04  3:41 ` [PATCH v10 04/20] x86/VPMU: Make vpmu macros a bit more efficient Boris Ostrovsky
2014-09-04  3:41 ` [PATCH v10 05/20] intel/VPMU: Clean up Intel VPMU code Boris Ostrovsky
2014-09-04  3:41 ` [PATCH v10 06/20] vmx: Merge MSR management routines Boris Ostrovsky
2014-09-08 16:07   ` Jan Beulich
2014-09-08 17:28     ` Boris Ostrovsky
2014-09-09  9:11       ` Jan Beulich
2014-09-04  3:41 ` [PATCH v10 07/20] x86/VPMU: Handle APIC_LVTPC accesses Boris Ostrovsky
2014-09-04  3:41 ` [PATCH v10 08/20] intel/VPMU: MSR_CORE_PERF_GLOBAL_CTRL should be initialized to zero Boris Ostrovsky
2014-09-04  3:41 ` [PATCH v10 09/20] x86/VPMU: Add public xenpmu.h Boris Ostrovsky
2014-09-10 14:45   ` Jan Beulich
2014-09-10 17:23     ` Boris Ostrovsky
2014-09-11  6:39       ` Jan Beulich
2014-09-11 13:54         ` Boris Ostrovsky
2014-09-11 14:55           ` Jan Beulich
2014-09-11 15:26             ` Boris Ostrovsky
2014-09-11 15:59               ` Jan Beulich
2014-09-11 16:51                 ` Boris Ostrovsky
2014-09-12  6:50                   ` Jan Beulich
2014-09-12 14:21                     ` Boris Ostrovsky
2014-09-12 14:38                       ` Jan Beulich
2014-09-12 15:18                         ` Boris Ostrovsky
2014-09-15 11:56                           ` Konrad Rzeszutek Wilk
2014-09-15 13:06                             ` Jan Beulich
2014-09-16  1:00                               ` Boris Ostrovsky
2014-09-16  0:49                             ` Boris Ostrovsky
2014-09-04  3:41 ` [PATCH v10 10/20] x86/VPMU: Make vpmu not HVM-specific Boris Ostrovsky
2014-09-04  3:41 ` [PATCH v10 11/20] x86/VPMU: Interface for setting PMU mode and flags Boris Ostrovsky
2014-09-10 15:05   ` Jan Beulich
2014-09-10 17:37     ` Boris Ostrovsky
2014-09-11  6:44       ` Jan Beulich
2014-09-11 14:12         ` Boris Ostrovsky
2014-09-11 14:59           ` Jan Beulich
2014-09-11 16:10             ` Boris Ostrovsky
2014-09-12  6:49               ` Jan Beulich
2014-09-12 14:12                 ` Boris Ostrovsky
2014-09-12 14:39                   ` Jan Beulich
2014-09-12 15:03                     ` Boris Ostrovsky
2014-09-12 15:30                       ` Jan Beulich
2014-09-12 15:54                         ` Boris Ostrovsky [this message]
2014-09-12 16:05                           ` Jan Beulich
2014-09-12 11:41   ` Dietmar Hahn
2014-09-12 14:25     ` Boris Ostrovsky
2014-09-15 13:35       ` Dietmar Hahn
2014-09-18  4:11   ` Tian, Kevin
2014-09-18 21:50     ` Boris Ostrovsky
2014-09-19  6:51       ` Jan Beulich
2014-09-19 12:42         ` Boris Ostrovsky
2014-09-19 13:28           ` Jan Beulich
2014-09-22 22:29             ` Tian, Kevin
2014-09-22 22:32       ` Tian, Kevin
2014-09-22 22:48         ` Boris Ostrovsky
2014-09-04  3:41 ` [PATCH v10 12/20] x86/VPMU: Initialize PMU for PV(H) guests Boris Ostrovsky
2014-09-04  3:41 ` [PATCH v10 13/20] x86/VPMU: When handling MSR accesses, leave fault injection to callers Boris Ostrovsky
2014-09-18  5:01   ` Tian, Kevin
2014-09-04  3:41 ` [PATCH v10 14/20] x86/VPMU: Add support for PMU register handling on PV guests Boris Ostrovsky
2014-09-04  3:41 ` [PATCH v10 15/20] x86/VPMU: Handle PMU interrupts for " Boris Ostrovsky
2014-09-10 15:30   ` Jan Beulich
2014-09-04  3:41 ` [PATCH v10 16/20] x86/VPMU: Merge vpmu_rdmsr and vpmu_wrmsr Boris Ostrovsky
2014-09-10 15:33   ` Jan Beulich
2014-09-18  4:16   ` Tian, Kevin
2014-09-04  3:41 ` [PATCH v10 17/20] x86/VPMU: Add privileged PMU mode Boris Ostrovsky
2014-09-10 15:39   ` Jan Beulich
2014-09-04  3:41 ` [PATCH v10 18/20] x86/VPMU: Save VPMU state for PV guests during context switch Boris Ostrovsky
2014-09-10 15:44   ` Jan Beulich
2014-09-04  3:41 ` [PATCH v10 19/20] x86/VPMU: NMI-based VPMU support Boris Ostrovsky
2014-09-04  3:41 ` [PATCH v10 20/20] x86/VPMU: Move VPMU files up from hvm/ directory Boris Ostrovsky
2014-09-10 15:48   ` Jan Beulich
2014-09-10 15:54 ` [PATCH v10 00/20] x86/PMU: Xen PMU PV(H) support Jan Beulich

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=54131741.90407@oracle.com \
    --to=boris.ostrovsky@oracle.com \
    --cc=Aravind.Gopalakrishnan@amd.com \
    --cc=JBeulich@suse.com \
    --cc=andrew.cooper3@citrix.com \
    --cc=eddie.dong@intel.com \
    --cc=jun.nakajima@intel.com \
    --cc=keir@xen.org \
    --cc=kevin.tian@intel.com \
    --cc=suravee.suthikulpanit@amd.com \
    --cc=tim@xen.org \
    --cc=xen-devel@lists.xen.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.