在 2023/3/7 23:23, Greg KH 写道: > On Mon, Mar 06, 2023 at 06:51:15PM +0800, Zhang Qiao wrote: >> >> >> 在 2023/3/6 18:05, Greg KH 写道: >>> On Mon, Mar 06, 2023 at 05:28:41PM +0800, Zhang Qiao wrote: >>>> >>>> >>>> 在 2023/3/6 17:19, Greg KH 写道: >>>>> On Mon, Mar 06, 2023 at 04:31:57PM +0800, Zhang Qiao wrote: >>>>>> >>>>>> >>>>>> 在 2023/3/5 12:02, Sasha Levin 写道: >>>>>>> This is a note to let you know that I've just added the patch titled >>>>>>> >>>>>>> sched/fair: sanitize vruntime of entity being placed >>>>>>> >>>>>>> to the 4.14-stable tree which can be found at: >>>>>>> http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary >>>>>>> >>>>>>> The filename of the patch is: >>>>>>> sched-fair-sanitize-vruntime-of-entity-being-placed.patch >>>>>>> and it can be found in the queue-4.14 subdirectory. >>>>>>> >>>>>>> If you, or anyone else, feels it should not be added to the stable tree, >>>>>>> please let <stable@xxxxxxxxxxxxxxx> know about it. >>>>>>> >>>>>>> >>>>>>> >>>>>>> commit 38247e1de3305a6ef644404ac818bc6129440eae >>>>>> >>>>>> Hi, >>>>>> This patch has significant impact on the hackbench.throughput [1]. >>>>>> Please don't backport this patch. >>>>>> >>>>>> [1] https://lore.kernel.org/lkml/202302211553.9738f304-yujie.liu@xxxxxxxxx/T/#u >>>>> >>>>> This link says it made hackbench.throughput faster, not slower, so why >>>>> would we NOT want it? >>>> >>>> Please see this section. In some cases, this patch reset task's vruntime by mistake and >>>> will lead to wrong results. >>>> >>>> >>>> On Tue, Feb 21, 2023 at 03:34:16PM +0800, kernel test robot wrote: >>>>> >>>>> FYI, In addition to that, the commit also has significant impact on the following tests: >>>>> >>>>> +------------------+--------------------------------------------------+ >>>>> | testcase: change | hackbench: hackbench.throughput -8.1% regression | >>>>> | test machine | 104 threads 2 sockets (Skylake) with 192G memory | >>>>> | test parameters | cpufreq_governor=performance | >>>>> | | ipc=socket | >>>>> | | iterations=4 | >>>>> | | mode=process | >>>>> | | nr_threads=100% | >>>>> +------------------+--------------------------------------------------+ >>>>> >>>>> Details are as below: >>> >>> So one benchmark did better, by a lot, and one did less, by a little? >>> Which one matters "more"> >>> >>> So Linus's tree now has a regression? Or not? I'm confused. We are >> >> Yes, Linus's tree also has a regression, and i have sent a patch[1] for fix this regression. >> >> >> [1]: https://lore.kernel.org/lkml/79850642-ebac-5c23-d32d-b28737dcb91e@xxxxxxxxxx/ >> >> thanks. >> Zhang qiao. > > Ok, I've dropped this from all stable queues now. Please let us know > when we can pick it up again and what the fixup commit id in Linus's > tree is when it lands there. Hi, The fixup patch has been merged into Linus's tree, its commit id is: a53ce18cacb477dd0513c607f187d16f0fa96f71 ("sched/fair: Sanitize vruntime of entity being migrated") thanks, Zhangqiao. > > thanks, > > greg k-h > . >
