From: Andrew Morton <akpm@linux-foundation.org>
To: Adrian Huang <adrianhuang0701@gmail.com>
Cc: Uladzislau Rezki <urezki@gmail.com>,
Christoph Hellwig <hch@infradead.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Adrian Huang <ahuang12@lenovo.com>
Subject: Re: [PATCH 1/1] mm: vmalloc: Optimize vmap_lazy_nr arithmetic when purging each vmap_area
Date: Fri, 30 Aug 2024 17:33:38 -0700 [thread overview]
Message-ID: <20240830173338.20c174604ebd8807405a0908@linux-foundation.org> (raw)
In-Reply-To: <20240829130633.2184-1-ahuang12@lenovo.com>
On Thu, 29 Aug 2024 21:06:33 +0800 Adrian Huang <adrianhuang0701@gmail.com> wrote:
> From: Adrian Huang <ahuang12@lenovo.com>
>
> When running the vmalloc stress on a 448-core system, observe the average
> latency of purge_vmap_node() is about 2 seconds by using the eBPF/bcc
> 'funclatency.py' tool [1].
>
> ...
>
> 3) The data in column "w/o patch" and "w/ patch"
> * Unit: micro seconds (us)
> * Each data is the average of 3-time measurements
>
> System w/o patch (us) w/ patch (us) Improvement (%)
> --------------- -------------- ------------- -------------
> 72-core server 2194 14 99.36%
> 192-core server 143799 1139 99.21%
> 448-core server 1992122 6883 99.65%
>
Holy cow. I'll add cc:stable to this. Partly because it fixes a
softlockup, partly because holy cow.
prev parent reply other threads:[~2024-08-31 0:33 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-29 13:06 Adrian Huang
2024-08-29 19:00 ` Uladzislau Rezki
2024-08-30 16:26 ` Uladzislau Rezki
2024-08-31 7:03 ` Christophe JAILLET
2024-09-02 17:03 ` Uladzislau Rezki
2024-09-02 12:00 ` Adrian Huang
2024-09-02 17:00 ` Uladzislau Rezki
2024-08-31 0:33 ` Andrew Morton [this message]
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