From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id AA1CA1876 for ; Mon, 26 May 2025 06:35:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748241348; cv=none; b=A4r7CmgMYynaztsx5BVEAYDH17R+uEQy9EHe9JV5v1GLpI4y5VZBRiyfh+85exyWbKKaRAYN5P+l48hMXwV1ZokwnlzzQacuzsp0b3XSDlkXJtWt4sNXM/9FTsPcSmNfhVZX5hXWzuH1a0Aps2d8HIEi6SA3tzkmRaZrzo82p/I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748241348; c=relaxed/simple; bh=xx8UQce5G1X0v9V8KkMFPofzo8dSpORDUL1PqfJD/AA=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=PQWQ4TacJOLlxDTxRyZLubtf9mBbyfvg/LKmUlq7EJioKWOZcamUspIF7vMH7VTpkDfq7IyI+sUNoZX7DZkioz9+IviDF91WbKU2ll0PoiKvIyVBp7Y8wPJl9gP/NlvPTj/zRVQvuqGLBYJHIyjomIxErNO/9LCdseGovU1/LF8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5004B153B; Sun, 25 May 2025 23:35:23 -0700 (PDT) Received: from MacBook-Pro.blr.arm.com (unknown [10.164.18.49]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id DECC53F5A1; Sun, 25 May 2025 23:35:35 -0700 (PDT) From: Dev Jain To: david@redhat.com, ziy@nvidia.com, willy@infradead.org, dhowells@redhat.com, hughd@google.com Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, ryan.roberts@arm.com, aneesh.kumar@kernel.org Subject: [QUESTION] xas_reload() in iter_xarray_populate_pages() Date: Mon, 26 May 2025 12:05:24 +0530 Message-Id: <20250526063524.22597-1-dev.jain@arm.com> X-Mailer: git-send-email 2.39.3 (Apple Git-146) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Hello all, After doing an xas_load() and xas_retry(), we take neither a reference nor a lock on the folio, and we do an xas_reload(). Is this just to reduce the time window for a race? If the above is true, then, there is a negligible window between xas_load() and xas_reload(), because only xas_retry() exists between them, so why to even reload()? Thanks, Dev