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Peter Anvin" , Andrew Morton , Dave Chinner , Qi Zheng , Roman Gushchin , Muchun Song , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Ben Segall , Mel Gorman , Valentin Schneider , K Prateek Nayak , Uladzislau Rezki , David Hildenbrand , Lorenzo Stoakes , "Liam R . Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Kees Cook , Sebastian Andrzej Siewior , Clark Williams , 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 Message-ID: <20260828144500.GW776954@noisy.programming.kicks-ass.net> References: <20260827232948.2520558-1-stevensd@google.com> <20260828124758.GP687043@noisy.programming.kicks-ass.net> <20260828103328.633bbfbc@gandalf.local.home> <20260828143540.GV776954@noisy.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260828143540.GV776954@noisy.programming.kicks-ass.net> X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 1B2C120003 X-Stat-Signature: tgxhgu3yj89u177up8tqqji1kehnigb1 X-Rspam-User: X-HE-Tag: 1787928309-671256 X-HE-Meta: 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 cJ6rTqQv LrhoBDRqY3GvH+Rh6Sn67dmSiStNRjxyVRugNiIa5AhVH6F59TyxEEp/g5TXx1WMYnJuEpgghwBYdjxQjfU3DXSCz/NMNBUjWk4nrovpjQ1eg2UFg+N8kMcMd+tlI82F23K1c37P+Hgu5msfe76k47yLJRYxR54lMEdrRnLVbrHSFG0nTZB4Smt1eWPEC9bqXRG59KzOmqAQjWlbVW2pX7OMCTd+fF2uG+SEx7VjfY4NaJxi50AHZ6C8wtSMuVsJXqZ2XehvJYBNQ2XFUwgrh/ctjrJG/w2TBDav3 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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 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.