From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.218.175.94 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792630275; b=oCX2lZtmuuxiEpaxjauDai4IItLUffs9ANJPWey5TF+IrbIZEQSpcQnGLoKFGz6F/O1x QKjvAzoH38dNM/OPsXqvERHbq+C2Qw28bb8BoIQ/7TEw5H25W2/kLZjBhHyfJyImlm7Iv ZVYnSy4vJ5bOSwU6FnefTsIlHewP3q3A60gvdp/5ZXRvIz8wsk0ZCbDjQBRHPpDSsvAen I4EZypKtgPDUn/jQ2COGkenyAfnNysH/rHbPm7r7MVuFN2ZrKNN0mTvXC8GJw8OKiBiMQ 2LCGIuxeSbS0nJlXPBUDAmL/yzjlF8i1TFWpr4E6NHDSFb4kj5pYSKF1xLKZ5DbhiTA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792630275; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:From:To:Cc:Subject:Date:Message-ID: X-Mailer:In-Reply-To:References:MIME-Version:Content-Type: Content-Transfer-Encoding; bh=YnSPPvpmQOUJ4waeQ3xaQjMx8WMQI2DxpZDvU9ftVls=; b=IJO2j6Co+wn/XS0STL/D2uu8dhGUMz6GBv7kaKu1vTXsdwU4DLg0zd0t9PA2w19lG1Oo H3zrruXa3GvZcD0mTaO95tUBLU6r9/V1tu/Q9ptlgD5abzQj9unIZYmlwfmPeg/1TiOMZ u/cwvcZpBCOFIR+hKvh4Mq4VGCIdqcBFRu9LNzD8zjxuU1qzAHM0wE6b6aDCVE6fhRt5/ xRxphej3YvwnGMWYRf3yKJjOui4t2FMXqLKQiGQ8mlf3kQPzS/VSO1h40GJyMRN2yzDC1 7LG/ee3ZQ53aYmuVr+tGELn5+in21Lp3k/SPVPzVLiYoKZ+T3pWIAJABzAqER4394EQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=xamMX0f6; arc=none smtp.remote-ip=91.218.175.94 Received: from mta0.migadu.com (out-94.mta0.migadu.com [91.218.175.94]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9CB93606A327 for ; Thu, 22 Oct 2026 00:51:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 9CB93606A327 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=xamMX0f6 X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=YnSPPvpmQOUJ4waeQ3xaQjMx8WMQI2DxpZDvU9ftVls=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1792630272; v=1; x=1793235072; b=xamMX0f6ZQj1tvTfxXMnc0w8Rx8uQHBBVHJg3ITje8SNSY/cKSWjjn/RC0DHWaFpw4XbyUFD Zp9eT0ZhFypfDN9ICNGIklCZSBVU0EGruN6Nk5fzk7UoyKdAPKWULJOSJ4RL2f8bBYX6eL8lpVl iAeN0ENRLoAjyb72wUic1PAk= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 3fa99ff370979236; Thu, 22 Oct 2026 00:51:12 +0000 X-Mizu-Trace-ID: 3fa99ff370979236 X-Migadu-Flow: FLOW_OUT From: Lance Yang To: samarth.colleges@gmail.com Cc: akpm@linux-foundation.org, david@kernel.org, xu.xin@linux.dev, chengming.zhou@linux.dev, peterx@redhat.com, kas@kernel.org, rppt@kernel.org, lance.yang@linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH v3] mm/ksm: keep soft-dirty when merging a page Date: Thu, 22 Oct 2026 08:51:02 +0800 Message-ID: <20261022005102.29011-1-lance.yang@linux.dev> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20261021182157.1873726-1-samarth.colleges@gmail.com> References: <20261021182157.1873726-1-samarth.colleges@gmail.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On Wed, Oct 21, 2026 at 11:21:57AM -0700, Samarth Narang wrote: >replace_page() maps the KSM page with a PTE built from scratch, so the >soft-dirty bit of the PTE it replaces is lost. A page written since >"clear_refs 4" then no longer shows as soft-dirty once it is merged, and >a soft-dirty based dumper treats it as unchanged. > >Copy the soft-dirty bit from the original PTE to the new PTE. > >Fixes: 0f8975ec4db2 ("mm: soft-dirty bits for user memory changes tracking") >Cc: stable@vger.kernel.org >Assisted-by: LLM >Signed-off-by: Samarth Narang >--- LGTM! Reviewed-by: Lance Yang