From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CE3C21624C5; Tue, 30 Jun 2026 14:03:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782828232; cv=none; b=ODLgBJOMnS3+wybBmf1QhhjDgqgtA2aKgYQxdH3sgVHPduXxz8zJcR6P+xx/7ubuy+tXs/4XERJzUQNwiqHykRye7rw1ZQLy6MChkXji2+p0oJqesFVV/h8SWxUp4EjA7cK7XXcybzfGYQkyLNz0RzWPTw8nVSOWDN36BtLxABc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782828232; c=relaxed/simple; bh=dnA8j7yv6A5vmXycr2jMzNb/UH+ARJ4tMS3HoqPlkDU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=halo8zg/TfgUDT2GHXvP/CkP6MKkWGi13yr+k1TZJdgTfK9xbOBvk3eUsb71sjzuKzBqJ3cUHVPSaKgVM5BiDelfcZ7nMAwiiaUC7X0uPgC0hjIIRpq/Fb9i/PYyXJ9DHjXAxae6IL9Dxu3ecasLHhGZfRCkGcZVia43Vi3jYFc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UXXpJ6Sc; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="UXXpJ6Sc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0A3781F000E9; Tue, 30 Jun 2026 14:03:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782828231; bh=ClHDIHe24wi5Yo5FWGkzU3UQ8Z+yVvMWp5sTcgmzYDE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=UXXpJ6ScDKGWLDx/HgUzJ5sqtbpEXFA2Ctwbjq6K2MtMcDWYaEX94Gk0asH/tH/kA iQfsHpW/G5+QPyWYgHQZ+raxxja9UDbc5KaMY8qqcx5ypmJbgKxucYJQz7ACutyeC+ hXENuFNiGhVTw4JzOBuubKINL8mI5jUDxDXctc9B3c0YOhH8OCYi8NOK8bcZ0amjtQ FoVq4/zPENKLAwqqXzyjFl4Xzc3DMIw7QoLRGt+hPIfl7nLtbnkvvzEeUYznXte1W1 /NuGYU8As7v2GwZj24s0uelAhG9/j9W/z3vQuKMfFMgElgdclAyuQMjdkU0Ftp8dFa WfGIV4wkZQ10A== From: SJ Park To: Igor Putko Cc: SJ Park , akpm@linux-foundation.org, damon@lists.linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] mm/damon/vaddr: remove redundant RCU lock Date: Tue, 30 Jun 2026 07:03:36 -0700 Message-ID: <20260630140337.91100-1-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260630130253.3843-1-igorpetindev@gmail.com> References: Precedence: bulk X-Mailing-List: damon@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Hello Igor, Thank you for this patch. >From next time, please give enough time for others to comment before posting a new revision of the patch. Also, please post a new revision as a new thread with a changelog [1] including links to previous revisions, rather than a reply to the previous revision. On Tue, 30 Jun 2026 16:02:53 +0300 Igor Putko wrote: > __damon_va_three_regions() is called only by damon_va_three_regions(), > which already holds mmap_read_lock(). Since mmap_read_lock() is held, > the maple tree and VMA list are protected from concurrent changes. > Remove the unnecessary rcu_read_lock() and rcu_read_unlock() calls. This is not explaining the test part change. Could you please update for that? Also, have you had a chance to theoretically or experiemently confirm the problem [2] that motivated to add the rcu_read_lock() at that place is not reintroduced by this change? If so, could you please add that to the commit log, too? Thanks, SJ [1] https://docs.kernel.org/process/submitting-patches.html#commentary [2] https://lore.kernel.org/b83651a0-5b24-4206-b860-cb54ffdf209b@roeck-us.net [...]