From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751623AbbAMH6C (ORCPT ); Tue, 13 Jan 2015 02:58:02 -0500 Received: from mailout3.w1.samsung.com ([210.118.77.13]:11097 "EHLO mailout3.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751569AbbAMH6A (ORCPT ); Tue, 13 Jan 2015 02:58:00 -0500 X-AuditID: cbfec7f5-b7fc86d0000066b7-66-54b4d006a725 Message-id: <54B4CFF3.5060100@samsung.com> Date: Tue, 13 Jan 2015 08:57:39 +0100 From: Andrzej Hajda User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 MIME-version: 1.0 To: Mike Turquette , linux-mm@kvack.org Cc: Andrzej Hajda , Marek Szyprowski , Kyungmin Park , linux-kernel@vger.kernel.org, andi@firstfloor.org, andi@lisas.de, Alexander Viro , Andrew Morton , sboyd@codeaurora.org Subject: Re: [PATCH 3/5] clk: convert clock name allocations to kstrdup_const References: <1421054323-14430-1-git-send-email-a.hajda@samsung.com> <1421054323-14430-4-git-send-email-a.hajda@samsung.com> <20150112231104.20842.5239@quantum> In-reply-to: <20150112231104.20842.5239@quantum> Content-type: text/plain; charset=utf-8 Content-transfer-encoding: 7bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrCLMWRmVeSWpSXmKPExsVy+t/xK7psF7aEGMxcpmVxa905Vos569ew WRy59p3d4vK/NywWZ5veAFm75rBZ3Fvzn9Vi7ZG77BZPJ1xks/hxppvF4vzf46wO3B6X+3qZ PObv/MjosenTJHaPO9f2sHmcmPGbxWPJTTWPvi2rGD0+b5Lz2PTkLVMAZxSXTUpqTmZZapG+ XQJXxv9Lu5kKpktWvP/UwtjAOEeoi5GDQ0LARGLqm7AuRk4gU0ziwr31bF2MXBxCAksZJWb3 /oFyPjFKnP46lRGkildAS2Lp7C/sIDaLgKrEqrf3WUBsNgFNib+bb7KB2KICERIfVn1lg6gX lPgx+R5YjYiAncS7E+uZQIYyC2xhkvh09CPYIGEBX4k/HddYILYtZpS4df4e2DZOAQOJzxd6 WEBOZRZQl5gyJRckzCwgL7F5zVvmCYwCs5DsmIVQNQtJ1QJG5lWMoqmlyQXFSem5RnrFibnF pXnpesn5uZsYITHzdQfj0mNWhxgFOBiVeHh3ZG8JEWJNLCuuzD3EKMHBrCTCazcHKMSbklhZ lVqUH19UmpNafIiRiYNTqoGxPvXAkn8pfEbbQjzPpp4+lxF6RnBNQkMaQ2H2/hDl9Zl9L10X nji4MI8hab5m7pzbLfVp/huUfnRWafifO8a150m215JYe9lVz7mO+jRPP7Pixzuhn+VLjnW/ Xv1FUMjLIivkz6EEV9cfmd62TSGzT3fUffh186bWhxM3F6669Wa5gZzUr2XxSizFGYmGWsxF xYkABDcIF3cCAAA= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/13/2015 12:11 AM, Mike Turquette wrote: > Quoting Andrzej Hajda (2015-01-12 01:18:41) >> Clock subsystem frequently performs duplication of strings located >> in read-only memory section. Replacing kstrdup by kstrdup_const >> allows to avoid such operations. >> >> Signed-off-by: Andrzej Hajda > Looks OK to me. Is there an easy trick to measuring the number of string > duplications saved short of instrumenting your code with a counter? I have just added pr_err in kstrdup_const: diff --git a/mm/util.c b/mm/util.c index c96fc4b..32a97b2 100644 --- a/mm/util.c +++ b/mm/util.c @@ -56,8 +56,10 @@ EXPORT_SYMBOL(kstrdup); const char *kstrdup_const(const char *s, gfp_t gfp) { - if (is_kernel_rodata((unsigned long)s)) + if (is_kernel_rodata((unsigned long)s)) { + pr_err("%s: %pS:%s\n", __func__, __builtin_return_address(0), s); return s; + } return kstrdup(s, gfp); } Probably printk buffer size should be increased: CONFIG_LOG_BUF_SHIFT=17 Regards Andrzej > > Regards, > Mike > >> --- >> drivers/clk/clk.c | 12 ++++++------ >> 1 file changed, 6 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c >> index f4963b7..27e644a 100644 >> --- a/drivers/clk/clk.c >> +++ b/drivers/clk/clk.c >> @@ -2048,7 +2048,7 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw) >> goto fail_out; >> } >> >> - clk->name = kstrdup(hw->init->name, GFP_KERNEL); >> + clk->name = kstrdup_const(hw->init->name, GFP_KERNEL); >> if (!clk->name) { >> pr_err("%s: could not allocate clk->name\n", __func__); >> ret = -ENOMEM; >> @@ -2075,7 +2075,7 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw) >> >> /* copy each string name in case parent_names is __initdata */ >> for (i = 0; i < clk->num_parents; i++) { >> - clk->parent_names[i] = kstrdup(hw->init->parent_names[i], >> + clk->parent_names[i] = kstrdup_const(hw->init->parent_names[i], >> GFP_KERNEL); >> if (!clk->parent_names[i]) { >> pr_err("%s: could not copy parent_names\n", __func__); >> @@ -2090,10 +2090,10 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw) >> >> fail_parent_names_copy: >> while (--i >= 0) >> - kfree(clk->parent_names[i]); >> + kfree_const(clk->parent_names[i]); >> kfree(clk->parent_names); >> fail_parent_names: >> - kfree(clk->name); >> + kfree_const(clk->name); >> fail_name: >> kfree(clk); >> fail_out: >> @@ -2112,10 +2112,10 @@ static void __clk_release(struct kref *ref) >> >> kfree(clk->parents); >> while (--i >= 0) >> - kfree(clk->parent_names[i]); >> + kfree_const(clk->parent_names[i]); >> >> kfree(clk->parent_names); >> - kfree(clk->name); >> + kfree_const(clk->name); >> kfree(clk); >> } >> >> -- >> 1.9.1 >>