From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f69.google.com (mail-pj1-f69.google.com [209.85.216.69]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E351F3E1680 for ; Thu, 27 Aug 2026 23:31:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.69 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787873498; cv=none; b=DpozYMLSM3S/87BjYx/Dwc/GKVDLf2bI4BnnR0ftu2y/mOQ9/dveVZMbKTR5VtOXq9D7bZaHdyJb/z/Yb5fFSbbh35VxvVkEn5LmSVZJqY6YggDgyZDpDN7yJj/iopeFO2m9A4cAs4R+jZjHZs0NFxZ6cXK78PgZQy/u5x4qHsE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787873498; c=relaxed/simple; bh=a4DHxg2eDawzpdV6ihnCiTe31A8NEYh6oPRQKJtlYWQ=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=QKH/Y/w0+IoVhDqFGyg6SvLCHzS1c04SsENJi2MXCiQP0FnZSBLgKJ6aj+EhyVUqjVx0ql/aaBoSqkxTl/R8xRbGFZIB8x8IbyL9379ya5xQGt9aWbZPpVWutsvgyEUJpvBhud7C7/f+6kcB04mdjwyyhn8vAVfXwCnrq4e0ZaQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--stevensd.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=IrEYzrZR; arc=none smtp.client-ip=209.85.216.69 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--stevensd.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="IrEYzrZR" Received: by mail-pj1-f69.google.com with SMTP id 98e67ed59e1d1-38e11baa66eso806938a91.2 for ; Thu, 27 Aug 2026 16:31:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1787873496; x=1788478296; darn=lists.linux.dev; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=THehtAVXPzXeOISNI+hN8Wh32bn5y3s9ZVH/HPQs5Ig=; b=IrEYzrZR9vZyT7kt5PoldbZw2n95qlCphQ3CTn96H3KoXOHGZBHVqTlrDaca8n0Zrb ePLQRBq0KBEx7cOg2n6GZiDbKn8U27KNqMjvuCT/GzjNcjwARbAYA0bspQkq1qKSA7ih oiYgmKIkINaD4qRnONqCNUzMjfxzfYVbejlbO/0aN+g6viOlcK4Hbcg3aYuC6jrzFP7H qtfi7UzurWLABL4IIBu5pbV2be1lc29MROmYQEd4noy8suEZarxvLz8xmA7wz0T1GXc2 GCsS+i7AL6M0HJcpBWxM5BuLKgVlZRa3V4GAt52XHRJjCFVvSKjS7gsd5aI31xhlko2M NBiQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1787873496; x=1788478296; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=THehtAVXPzXeOISNI+hN8Wh32bn5y3s9ZVH/HPQs5Ig=; b=UUnM/AaFtIqxuMvl7djYOZ0mD/8nag5KU+Z+vYE7hKnBdUX1CIui0A9Z30fGDP5DBr wj7eODDRicBPiM4nGOmDIOoKr8acvP+/BSMaoHMRvZwgXk4TJpwYHA+ec5CI4TN8gKGi S/gA76ILDIv61X+hYmLM8sAi0TtM2Be+YuxE9Q4q9IJRHuuR5mBF/u8750R383Fwz4/C DuaunDuw6BKuEz6NYTSy6VJY/9kTL/Q6giU/OrMKPkztD6LuLYwsC4ivP/FGRnhvK/Qb B0wrZ+Hjes+KGPx6peShHcDIL5GYbrbbNnnZTyrc6MzBELw7+ey6wd2h1HOFdF7ddAfA 7A0A== X-Forwarded-Encrypted: i=1; AHgh+Ro46qQE6XwlDoY7f4+1vXAx0k+OwTYmv3Td9A1RHeeZML91v8YzfpuFpEk4jR9DtLdhykaaK561RgvvsC6xCg==@lists.linux.dev X-Gm-Message-State: AFuF++mVLgmCBe1ZyCSGjhcgXuZVQb7xMsWwksu32Bmcf9zsVFqjNSe7 JrgpBifsNYWYrEZSoK9Zi6dfmnOdpZiwuq/5mXoHqiH+bpEaAoHxDTogm+xTpHmZmr+5q3IV8cR dDZjkZ1sABD7fDw== X-Received: from dlbsj13.prod.google.com ([2002:a05:7022:f90d:b0:139:d9c7:3cf4]) (user=stevensd job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:2c88:b0:396:b98b:a3c2 with SMTP id 98e67ed59e1d1-396d0f52a0amr5303479a91.8.1787873495813; Thu, 27 Aug 2026 16:31:35 -0700 (PDT) Date: Thu, 27 Aug 2026 16:29:48 -0700 In-Reply-To: <20260827232948.2520558-1-stevensd@google.com> Precedence: bulk X-Mailing-List: linux-rt-devel@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260827232948.2520558-1-stevensd@google.com> X-Mailer: git-send-email 2.55.0.897.gb25b4bd76c-goog Message-ID: <20260827232948.2520558-11-stevensd@google.com> Subject: [RFC 10/10] arm64: Enable reclaimable stacks From: David Stevens To: Catalin Marinas , Will Deacon , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H . Peter Anvin" , Andrew Morton , Dave Chinner , Qi Zheng , Roman Gushchin , Muchun Song , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , 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 Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-rt-devel@lists.linux.dev, David Stevens Content-Type: text/plain; charset="UTF-8" Implement top_of_blocked_task_stack() to get the stack pointer out of a thread_struct and enable HAVE_ARCH_RECLAIMABLE_STACK. Signed-off-by: David Stevens --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/processor.h | 5 +++++ 2 files changed, 6 insertions(+) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index b3afe0688919..262a4fddce19 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -173,6 +173,7 @@ config ARM64 select HAVE_ARCH_TRACEHOOK select HAVE_ARCH_TRANSPARENT_HUGEPAGE select HAVE_ARCH_VMAP_STACK + select HAVE_ARCH_RECLAIMABLE_STACK select HAVE_ARM_SMCCC select HAVE_ASM_MODVERSIONS select HAVE_EBPF_JIT diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index c2a627f39314..f5a550835c94 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -204,6 +204,11 @@ struct thread_struct { #endif }; +static inline unsigned long top_of_blocked_task_stack(struct thread_struct *thread) +{ + return thread->cpu_context.sp; +} + static inline unsigned int thread_get_vl(struct thread_struct *thread, enum vec_type type) { -- 2.55.0.897.gb25b4bd76c-goog