From nobody Mon Jun 8 04:20:40 2026 Received: from mail-pf1-f182.google.com (mail-pf1-f182.google.com [209.85.210.182]) (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 156E71F09AD for ; Sun, 7 Jun 2026 13:48:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780840139; cv=none; b=hWlDYHH2RiJiqJAmmAvFCp9OQoV3ybspdBnXm39OkpqrOqtVePAQ4kZJ83h7mk2m5MiTKT/xYUZVDFFMjjogA2lGNARX5hZPOONTXoJj67zNUe+IvBhiVoZyKbs/e1WPpYAKtwAj+8TG1xh3yQURA8BO5OR817JbR4WGTLHIdpg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780840139; c=relaxed/simple; bh=Cvgq6hNpp3pN4v1ssOQj4C8t60KcXC1VRT5noQtt7FQ=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=Bx3jgb0ReH1vpiYGFGNxK0bVJqH4y8caJsxuD2TMET4QqPqsT+hRqReSggh+ZIDaogehfBXuXHMK3gLIy54qwqO+U0hVhNdj79wvyxz7UMi+kkWUarOUAEFZW6XBKWZgrtAhGHdfzqT9LUu1u3g8CjW/8TPjyzta0Xp3jNUtJx4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=LVgqnzbf; arc=none smtp.client-ip=209.85.210.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="LVgqnzbf" Received: by mail-pf1-f182.google.com with SMTP id d2e1a72fcca58-842338c18e0so2440663b3a.1 for ; Sun, 07 Jun 2026 06:48:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1780840137; x=1781444937; darn=vger.kernel.org; h=cc:to:message-id:content-transfer-encoding:mime-version:subject :date:from:from:to:cc:subject:date:message-id:reply-to; bh=0CTxO7Hcxcsa+DE7y8PeV+aprK4GKwNhOSFfFn9fnPw=; b=LVgqnzbfyLT8FPvhTWKmeh2dwJ6rna58XGApWk9ocFdt1pDEq2UchO4n2rEPyNByGi M25rtQyFerK9ywXfWIQcZ2hFs1Bv8um1WfOWqrTQvhByJjAecw37zE527N+wRygXep5i l12zd1D0ceF9n63NoEZF4BIje+ZdZ8YO1iLUr6cLXg2sfbI7DN9qWhx980Tz7aO9AZ5b WxyXo0NEowo6xBt86QjQYZjWUOzKK4miZEs/xcmDWNw7bi4eRpKzqjxBi4qnP8AwWW/C 6va0JFY2BnDv8lMjVS9sOrfz3d/zMf/+yv6Ypx2JCwz2cBPD/MZRn7AM5JCj+wXjoxqg NFqA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1780840137; x=1781444937; h=cc:to:message-id:content-transfer-encoding:mime-version:subject :date:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=0CTxO7Hcxcsa+DE7y8PeV+aprK4GKwNhOSFfFn9fnPw=; b=J4Ag+PBekScPpi6WUoC6mTcx3eaAx2wXjgGAyG3yPQ1kFr0voCNBmJ7cptDyczkRiq bvDY8bIUc1vaHTt+URV6pd0fyeHXB8CQnltLQeCDR31Bf8ZB17xJEjknUhQjOv3bSlhU Qxk+9g1ZqmHkqwUT25YZjL2F1QWYMQeHrImWtAN490tMePLuV7kyUup4IPhkP3l5h7ln bO8fjrJoiCcLyLQTm3BrUnKW63hNxWs/gSfaeO2fu0v+Ej1CZJyzRLkH+YjyBFqF1o1z kabJOopd3r4mItXO1fbrlJh7ag56q10BiJKNqVvH2mg9wMHK5nICQYfzgZXlc0KQdrW6 GWfg== X-Forwarded-Encrypted: i=1; AFNElJ/obg94bvWJ5BaCwzaVHdjwSjOVamBqea/r9nKAwKKYcnKQ0Klhvh5KfQ75s06/hXVKLukdw66bTxMc0b0=@vger.kernel.org X-Gm-Message-State: AOJu0YyDN4bNVxMUaMe7qSjj8wemKBEXKn5xGLG8RIDKbhtwtHZZNbde pF24rUxxf91TgnekqyXrcc8eNtgvoKRYu9aNpjswmncIqrvx+K+uqeRf X-Gm-Gg: Acq92OFRpD+Yv3ztwKACIE5THSOs1XjLr4pQKCtrErAgWEnB6UPNljM5hZIYSNqcWuh ms9+vKVYABAb9Mu7PTD0kr0dqFoqVHLyXiu5eR4C6lG2t17/SNGFC8Zt60NtwklsuW9owoEqlu/ qX2yAzdsJ9AoqnL1IMpG1jbzljfN61MNIXFbaqdY3NIWyUXWfr7XqEVCdtfYtZ2D/YMNuJXU3gY Su/BoH3XERMnCTCi0jaLNTP8SxUvom6+Ct+F0JceSMQqWLG2XmFk0R/E3xXG4VAlOEKEUjrXeyF qakJr2Iwvi+Naglwt92Pko+u5JsEkamHn9dZB6M0U7VkMAfeo2GVKCXyNdca9kbfl3GU9swdPAV Y7sX9eRRWUKOk31rVGLtaA5ij/kkxZ51Bg6zcb6LAQ+JrQyQ3FjMHY8dufDf4JypHYoxXD+7ZpK pNFZ7V0LSarG7n3ydNA5rCBW29RjDTilwSnQ== X-Received: by 2002:a05:6a00:234a:b0:842:7221:dbb8 with SMTP id d2e1a72fcca58-842b0e57474mr10850926b3a.15.1780840137253; Sun, 07 Jun 2026 06:48:57 -0700 (PDT) Received: from [127.0.0.1] ([116.80.91.208]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-84282918b8csm14365235b3a.57.2026.06.07.06.48.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 07 Jun 2026 06:48:56 -0700 (PDT) From: Cunlong Li Date: Sun, 07 Jun 2026 21:48:52 +0800 Subject: [PATCH] mm/damon/vaddr: drop redundant mmap_read_lock from damon_va_three_regions Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260607-rcu-v1-1-3c9f5995a3a0@gmail.com> X-B4-Tracking: v=1; b=H4sIAMN2JWoC/6tWKk4tykwtVrJSqFYqSi3LLM7MzwNyDHUUlJIzE vPSU3UzU4B8JSMDIzMDMwNz3aLkUl0jkyRjI5NUgzQDczMloMqCotS0zAqwKdGxtbUAK8Q7fFU AAAA= X-Change-ID: 20260607-rcu-24b324e0f076 To: SeongJae Park , Andrew Morton Cc: damon@lists.linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Cunlong Li X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1780840135; l=1761; i=shenxiaogll@gmail.com; s=20260517; h=from:subject:message-id; bh=Cvgq6hNpp3pN4v1ssOQj4C8t60KcXC1VRT5noQtt7FQ=; b=PejStRa7IarY8QPXkGy/Nf155AyVFmcMEsGQmhZELK5FxMOFhB4kAhKN2VHYFQy/+DFy14J/h Ao3Po6T9PcuAN5TahK0z1kybF+HmDYUawk7HaxWMBHIsKnPC8I8s9P/ X-Developer-Key: i=shenxiaogll@gmail.com; a=ed25519; pk=SKFifnqPdsvsjuhUiq+Y9vtCdhyZ/LrRcfYn8eRq6AE= __damon_va_three_regions() already walks VMAs under rcu_read_lock(), so the outer mmap_read_lock() is no longer needed. --- Signed-off-by: Cunlong Li --- mm/damon/vaddr.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c index b069dbc7e3d2..27e34596c43b 100644 --- a/mm/damon/vaddr.c +++ b/mm/damon/vaddr.c @@ -77,7 +77,7 @@ static int __damon_va_three_regions(struct mm_struct *mm, struct damon_addr_range first_gap =3D {0}, second_gap =3D {0}; VMA_ITERATOR(vmi, mm, 0); struct vm_area_struct *vma, *prev =3D NULL; - unsigned long start; + unsigned long start =3D 0, last_vma_end =3D 0; =20 /* * Find the two biggest gaps so that first_gap > second_gap > others. @@ -104,6 +104,7 @@ static int __damon_va_three_regions(struct mm_struct *m= m, } next: prev =3D vma; + last_vma_end =3D vma->vm_end; } rcu_read_unlock(); =20 @@ -120,7 +121,7 @@ static int __damon_va_three_regions(struct mm_struct *m= m, regions[1].start =3D ALIGN(first_gap.end, DAMON_MIN_REGION_SZ); regions[1].end =3D ALIGN(second_gap.start, DAMON_MIN_REGION_SZ); regions[2].start =3D ALIGN(second_gap.end, DAMON_MIN_REGION_SZ); - regions[2].end =3D ALIGN(prev->vm_end, DAMON_MIN_REGION_SZ); + regions[2].end =3D ALIGN(last_vma_end, DAMON_MIN_REGION_SZ); =20 return 0; } @@ -140,9 +141,7 @@ static int damon_va_three_regions(struct damon_target *= t, if (!mm) return -EINVAL; =20 - mmap_read_lock(mm); rc =3D __damon_va_three_regions(mm, regions); - mmap_read_unlock(mm); =20 mmput(mm); return rc; --- base-commit: 8e65320d91cdc3b241d4b94855c88459b91abf66 change-id: 20260607-rcu-24b324e0f076 Best regards, --=20 Cunlong Li