From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2978FC43334 for ; Mon, 13 Jun 2022 20:35:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239541AbiFMUdf (ORCPT ); Mon, 13 Jun 2022 16:33:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35214 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232570AbiFMUdA (ORCPT ); Mon, 13 Jun 2022 16:33:00 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0E1B528726 for ; Mon, 13 Jun 2022 12:23:12 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id E2B67B8128D for ; Mon, 13 Jun 2022 19:23:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 454CBC3411F; Mon, 13 Jun 2022 19:23:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1655148188; bh=XOWacsSFy4qQVUe4yC1Lr3xCRJ6lmmqOdxcVjKLkxx8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YCizNenf2u5d4ieuePcVEjzZ2J39Sj48RNI7hGwMQwP/Abq9boO2PmAU5PmHVHtos K5zCk0uhTbHp67T5LrOHdPQirivVTyL+mIvseF7cg/vJOrabOuc9GBmWbd90836pWq 80AdC/J8slOkYQUhjnYmijIIcNH46See1cJo/ApvzWcC+dlTcwICTFJjEgsTLgpumq zhRoiHq0nEHIAs+a8Tg5cXkc04tSfs/P9Czxgry3qfzQnD0ELzWBhGFQl6u5FvIPxB /L61PzRRY849tV0+hguoIHWX/5IzklIs3N5PskB/9YNMI13TArwYX9VDHYDvdNiENf OjDhaCgR8CI+w== From: SeongJae Park To: SeongJae Park , Andrew Morton Cc: damon@lists.linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/8] mm/damon/dbgfs: add and use mappings between 'schemes' action inputs and 'damos_action' values Date: Mon, 13 Jun 2022 19:22:53 +0000 Message-Id: <20220613192301.8817-2-sj@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220613192301.8817-1-sj@kernel.org> References: <20220613192301.8817-1-sj@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org DAMON debugfs interface assumes users will write 'damos_action' value directly to the 'schemes' file. This makes adding new 'damos_action' in the middle of its definition breaks the backward compatibility of DAMON debugfs interface, as values of some 'damos_action' could be changed. To mitigate the situation, this commit adds mappings between the user inputs and 'damos_action' value and makes DAMON debugfs code uses those. Signed-off-by: SeongJae Park --- mm/damon/dbgfs.c | 64 +++++++++++++++++++++++++++++++++++++----------- 1 file changed, 50 insertions(+), 14 deletions(-) diff --git a/mm/damon/dbgfs.c b/mm/damon/dbgfs.c index 5ae810927309..cb8a7e9926a4 100644 --- a/mm/damon/dbgfs.c +++ b/mm/damon/dbgfs.c @@ -97,6 +97,31 @@ static ssize_t dbgfs_attrs_write(struct file *file, return ret; } +/* + * Return corresponding dbgfs' scheme action value (int) for the given + * damos_action if the given damos_action value is valid and supported by + * dbgfs, negative error code otherwise. + */ +static int damos_action_to_dbgfs_scheme_action(enum damos_action action) +{ + switch (action) { + case DAMOS_WILLNEED: + return 0; + case DAMOS_COLD: + return 1; + case DAMOS_PAGEOUT: + return 2; + case DAMOS_HUGEPAGE: + return 3; + case DAMOS_NOHUGEPAGE: + return 4; + case DAMOS_STAT: + return 5; + default: + return -EINVAL; + } +} + static ssize_t sprint_schemes(struct damon_ctx *c, char *buf, ssize_t len) { struct damos *s; @@ -109,7 +134,7 @@ static ssize_t sprint_schemes(struct damon_ctx *c, char *buf, ssize_t len) s->min_sz_region, s->max_sz_region, s->min_nr_accesses, s->max_nr_accesses, s->min_age_region, s->max_age_region, - s->action, + damos_action_to_dbgfs_scheme_action(s->action), s->quota.ms, s->quota.sz, s->quota.reset_interval, s->quota.weight_sz, @@ -160,18 +185,27 @@ static void free_schemes_arr(struct damos **schemes, ssize_t nr_schemes) kfree(schemes); } -static bool damos_action_valid(int action) +/* + * Return corresponding damos_action for the given dbgfs input for a scheme + * action if the input is valid, negative error code otherwise. + */ +static enum damos_action dbgfs_scheme_action_to_damos_action(int dbgfs_action) { - switch (action) { - case DAMOS_WILLNEED: - case DAMOS_COLD: - case DAMOS_PAGEOUT: - case DAMOS_HUGEPAGE: - case DAMOS_NOHUGEPAGE: - case DAMOS_STAT: - return true; + switch (dbgfs_action) { + case 0: + return DAMOS_WILLNEED; + case 1: + return DAMOS_COLD; + case 2: + return DAMOS_PAGEOUT; + case 3: + return DAMOS_HUGEPAGE; + case 4: + return DAMOS_NOHUGEPAGE; + case 5: + return DAMOS_STAT; default: - return false; + return -EINVAL; } } @@ -189,7 +223,8 @@ static struct damos **str_to_schemes(const char *str, ssize_t len, int pos = 0, parsed, ret; unsigned long min_sz, max_sz; unsigned int min_nr_a, max_nr_a, min_age, max_age; - unsigned int action; + unsigned int action_input; + enum damos_action action; schemes = kmalloc_array(max_nr_schemes, sizeof(scheme), GFP_KERNEL); @@ -204,7 +239,7 @@ static struct damos **str_to_schemes(const char *str, ssize_t len, ret = sscanf(&str[pos], "%lu %lu %u %u %u %u %u %lu %lu %lu %u %u %u %u %lu %lu %lu %lu%n", &min_sz, &max_sz, &min_nr_a, &max_nr_a, - &min_age, &max_age, &action, "a.ms, + &min_age, &max_age, &action_input, "a.ms, "a.sz, "a.reset_interval, "a.weight_sz, "a.weight_nr_accesses, "a.weight_age, &wmarks.metric, @@ -212,7 +247,8 @@ static struct damos **str_to_schemes(const char *str, ssize_t len, &wmarks.low, &parsed); if (ret != 18) break; - if (!damos_action_valid(action)) + action = dbgfs_scheme_action_to_damos_action(action_input); + if ((int)action < 0) goto fail; if (min_sz > max_sz || min_nr_a > max_nr_a || min_age > max_age) -- 2.25.1