From: Peter Zijlstra <peterz@infradead.org>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>,
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>,
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
Subject: Re: [RFC 06/10] Reclaim memory from blocked kernel stacks
Date: Mon, 31 Aug 2026 09:07:33 +0200 [thread overview]
Message-ID: <20260831070733.GS687043@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <20260831065509.qqEtERDB@linutronix.de>
On Mon, Aug 31, 2026 at 08:55:09AM +0200, Sebastian Andrzej Siewior wrote:
> (stack tracer running)
> Depth Size Location (60 entries)
> ----- ---- --------
> 0) 8176 48 __css_rstat_updated+0x9/0x150
> 1) 8128 8 __cgroup_account_cputime+0x2f/0x50
> 2) 8120 48 update_se+0x10c/0x1b0
> 3) 8072 48 update_curr+0x31/0x180
> 4) 8024 56 put_prev_entity+0x153/0x1f0
> 5) 7968 136 pick_next_task_fair+0x684/0x8e0
> 6) 7832 120 __schedule+0x1ca/0x1130
> 7) 7712 8 preempt_schedule_irq+0x38/0x60
> 8) 7704 72 irqentry_exit+0x148/0x6b0
> 9) 7632 136 asm_sysvec_apic_timer_interrupt+0x1a/0x20
> 10) 7496 240 HUF_compress1X_usingCTable_internal_bmi2+0x12d2/0x1c40
>
> Does this stack tracer distinguish between the kernel-stack and
> IRQ-stack? I would expect asm_sysvec_apic_timer_interrupt() on the
> IRQ-stack and not adding weight to the kernel stack.
This is the return from interrupt path, irqentry_exit() is right after
we switch back from the IRQ stack and are back on the task stack. We
have to be, in order to schedule the task and all that.
next prev parent reply other threads:[~2026-08-31 7:08 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-27 23:29 [RFC 00/10] Reclaimable " 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
2026-08-29 0:18 ` David Stevens
2026-08-29 8:39 ` Peter Zijlstra
2026-08-29 8:43 ` Peter Zijlstra
2026-08-31 17:44 ` David Stevens
2026-08-28 12:41 ` Peter Zijlstra
2026-08-28 12:57 ` Peter Zijlstra
2026-08-28 23:33 ` David Stevens
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
2026-08-31 6:55 ` Sebastian Andrzej Siewior
2026-08-31 7:07 ` Peter Zijlstra [this message]
2026-08-31 15:13 ` Steven Rostedt
2026-09-01 12:32 ` Peter Zijlstra
2026-09-01 12:01 ` Will Deacon
2026-08-28 20:50 ` David Stevens
2026-08-29 8:49 ` Peter Zijlstra
2026-08-29 14:49 ` Matthew Wilcox
2026-08-31 7:14 ` Peter Zijlstra
2026-08-31 7:36 ` Sebastian Andrzej Siewior
2026-08-31 14:03 ` Vlastimil Babka (SUSE)
2026-08-31 14:19 ` Sebastian Andrzej Siewior
2026-08-28 21:17 ` David Stevens
2026-08-31 8:08 ` Sebastian Andrzej Siewior
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
2026-09-01 9:27 ` Alice Ryhl
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
2026-08-28 16:10 ` Steven Rostedt
2026-08-28 17:58 ` David Stevens
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20260831070733.GS687043@noisy.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=akpm@linux-foundation.org \
--cc=bigeasy@linutronix.de \
--cc=bp@alien8.de \
--cc=bsegall@google.com \
--cc=catalin.marinas@arm.com \
--cc=clrkwllms@kernel.org \
--cc=dave.hansen@linux.intel.com \
--cc=david@fromorbit.com \
--cc=david@kernel.org \
--cc=dietmar.eggemann@arm.com \
--cc=hpa@zytor.com \
--cc=juri.lelli@redhat.com \
--cc=kees@kernel.org \
--cc=kprateek.nayak@amd.com \
--cc=liam@infradead.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-rt-devel@lists.linux.dev \
--cc=ljs@kernel.org \
--cc=mgorman@suse.de \
--cc=mhocko@suse.com \
--cc=mingo@redhat.com \
--cc=muchun.song@linux.dev \
--cc=qi.zheng@linux.dev \
--cc=roman.gushchin@linux.dev \
--cc=rostedt@goodmis.org \
--cc=rppt@kernel.org \
--cc=stevensd@google.com \
--cc=suleiman@google.com \
--cc=surenb@google.com \
--cc=tglx@kernel.org \
--cc=urezki@gmail.com \
--cc=vbabka@kernel.org \
--cc=vincent.guittot@linaro.org \
--cc=vschneid@redhat.com \
--cc=will@kernel.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®