From: Vlastimil Babka <vbabka@suse.cz>
To: Roman Gushchin <guro@fb.com>, Dennis Zhou <dennis@kernel.org>
Cc: Tejun Heo <tj@kernel.org>, Christoph Lameter <cl@linux.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1 0/5] percpu: partial chunk depopulation
Date: Wed, 7 Apr 2021 13:09:47 +0200 [thread overview]
Message-ID: <9da8492f-2ffb-2d4f-c937-93df28f0215a@suse.cz> (raw)
In-Reply-To: <20210401214301.1689099-1-guro@fb.com>
On 4/1/21 11:42 PM, Roman Gushchin wrote:
> In our production experience the percpu memory allocator is sometimes struggling
> with returning the memory to the system. A typical example is a creation of
> several thousands memory cgroups (each has several chunks of the percpu data
> used for vmstats, vmevents, ref counters etc). Deletion and complete releasing
> of these cgroups doesn't always lead to a shrinkage of the percpu memory.
>
> The underlying problem is the fragmentation: to release an underlying chunk
> all percpu allocations should be released first. The percpu allocator tends
> to top up chunks to improve the utilization. It means new small-ish allocations
> (e.g. percpu ref counters) are placed onto almost filled old-ish chunks,
> effectively pinning them in memory.
>
> This patchset pretends to solve this problem by implementing a partial
Really "pretends"? :) Or did you mean "attempts"?
prev parent reply other threads:[~2021-04-07 11:09 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-01 21:42 [PATCH v1 0/5] percpu: partial chunk depopulation Roman Gushchin
2021-04-01 21:42 ` [PATCH v1 1/5] percpu: split __pcpu_balance_workfn() Roman Gushchin
2021-04-01 21:42 ` [PATCH v1 2/5] percpu: make pcpu_nr_empty_pop_pages per chunk type Roman Gushchin
2021-04-01 21:42 ` [PATCH v1 3/5] percpu: generalize pcpu_balance_populated() Roman Gushchin
2021-04-01 21:43 ` [PATCH v1 4/5] percpu: fix a comment about the chunks ordering Roman Gushchin
2021-04-01 21:43 ` [PATCH v1 5/5] percpu: implement partial chunk depopulation Roman Gushchin
2021-04-05 23:02 ` Dennis Zhou
2021-04-07 11:09 ` Vlastimil Babka [this message]
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