From: Peter Zijlstra <peterz@infradead.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: David Stevens <stevensd@google.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, Thomas Gleixner <tglx@kernel.org>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org, "H . Peter Anvin" <hpa@zytor.com>,
Andrew Morton <akpm@linux-foundation.org>,
Dave Chinner <david@fromorbit.com>, Qi Zheng <qi.zheng@linux.dev>,
Roman Gushchin <roman.gushchin@linux.dev>,
Muchun Song <muchun.song@linux.dev>,
Juri Lelli <juri.lelli@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
Valentin Schneider <vschneid@redhat.com>,
K Prateek Nayak <kprateek.nayak@amd.com>,
Uladzislau Rezki <urezki@gmail.com>,
David Hildenbrand <david@kernel.org>,
Lorenzo Stoakes <ljs@kernel.org>,
"Liam R . Howlett" <liam@infradead.org>,
Vlastimil Babka <vbabka@kernel.org>,
Mike Rapoport <rppt@kernel.org>,
Suren Baghdasaryan <surenb@google.com>,
Michal Hocko <mhocko@suse.com>, Kees Cook <kees@kernel.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Clark Williams <clrkwllms@kernel.org>,
suleiman@google.com, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org,
linux-rt-devel@lists.linux.dev, jstultz@google.com
Subject: Re: [RFC 00/10] Reclaimable kernel stacks
Date: Fri, 28 Aug 2026 16:45:00 +0200 [thread overview]
Message-ID: <20260828144500.GW776954@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <20260828143540.GV776954@noisy.programming.kicks-ass.net>
On Fri, Aug 28, 2026 at 04:35:40PM +0200, Peter Zijlstra wrote:
> On Fri, Aug 28, 2026 at 10:33:28AM -0400, Steven Rostedt wrote:
> > On Fri, 28 Aug 2026 14:47:58 +0200
> > Peter Zijlstra <peterz@infradead.org> wrote:
> >
> > > > On Android, system processes typically have 2000-3000 threads. App
> > > > processes add 1000s more threads on top of this.
> > >
> > > WTF ?!? Why does that all spawn *that* many threads? Perhaps work on
> > > reducing that some?
> >
> > I guess you never ran Java ;-)
>
> Of course not; why would you want to do something that silly ;-)
I realized I actually have a Java thing, the kids have Minecraft, so I
booted that up and I found all of 108 threads. Which is still kinda
insane, but nowhere near the 1000s per app as claimed.
Reducing the thread count from O(1e3) to O(1e2) would win far more
memory than any thread stack shenanigans would.
next prev parent reply other threads:[~2026-08-28 14:45 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-27 23:29 David Stevens
2026-08-27 23:29 ` [RFC 01/10] Add !MEMCG memcg_list_lru_alloc implementation David Stevens
2026-08-27 23:29 ` [RFC 02/10] mm/vmalloc: Skip vmallocinfo NUMA stats for VM_SPARSE David Stevens
2026-08-27 23:29 ` [RFC 03/10] fork: refactor vmap stack alloc/free into helpers David Stevens
2026-08-27 23:29 ` [RFC 04/10] mm: vmalloc: support creating aligned vm areas David Stevens
2026-08-27 23:29 ` [RFC 05/10] fork: allocate reclaimable stacks with VM_SPARSE David Stevens
2026-08-27 23:29 ` [RFC 06/10] Reclaim memory from blocked kernel stacks David Stevens
2026-08-27 23:53 ` sashiko-bot
2026-08-28 11:54 ` Peter Zijlstra
2026-08-28 12:01 ` Peter Zijlstra
2026-08-28 12:04 ` Peter Zijlstra
2026-08-28 12:41 ` Peter Zijlstra
2026-08-28 12:57 ` Peter Zijlstra
2026-08-28 13:36 ` Sebastian Andrzej Siewior
2026-08-28 13:59 ` Peter Zijlstra
2026-08-28 14:25 ` Peter Zijlstra
2026-08-28 15:58 ` Sebastian Andrzej Siewior
2026-08-28 15:10 ` Sebastian Andrzej Siewior
2026-08-28 19:08 ` Steven Rostedt
2026-08-28 19:13 ` Steven Rostedt
2026-08-28 19:17 ` Steven Rostedt
2026-08-28 20:50 ` David Stevens
2026-08-28 21:17 ` David Stevens
2026-08-27 23:29 ` [RFC 07/10] Reclaim stacks via a shrinker David Stevens
2026-08-27 23:29 ` [RFC 08/10] Set PF_RECLAIMABLE_STACK in various places David Stevens
2026-08-27 23:43 ` sashiko-bot
2026-08-28 6:33 ` K Prateek Nayak
2026-08-27 23:29 ` [RFC 09/10] x86: Enable reclaimable stacks David Stevens
2026-08-27 23:29 ` [RFC 10/10] arm64: " David Stevens
2026-08-28 12:47 ` [RFC 00/10] Reclaimable kernel stacks Peter Zijlstra
2026-08-28 14:33 ` Steven Rostedt
2026-08-28 14:35 ` Peter Zijlstra
2026-08-28 14:45 ` Peter Zijlstra [this message]
2026-08-28 16:10 ` Steven Rostedt
2026-08-28 17:58 ` David Stevens
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