From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 59EDD35E94E for ; Thu, 14 May 2026 12:22:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778761365; cv=none; b=GR/Hu/U5P1GxEmUuxXvWpMCvJzEHkItmA0gzHbjOm+GBVc2lDTckL7BkECCnyGnvfuW5icPtbwh+Zx4+8vc8arfkIJeNmF8FwocEJ0tMjsW+B1E5Z4dDtyp+1BN4a85FPfSJW8PdK2NQMiPvUjjjuCVFpjybM4Mi/Z/ViBXlSl4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778761365; c=relaxed/simple; bh=Yqxi9WNOyPgZenBZoE5iwSQ74FymEj/lLJ/BxCqBOGY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=EHyXij33bwLabiPEsc+mD1qPnXfJXdThmK9GcJzXGEPB1fHf9AFCRSv3PafOcEg4JJQFfqKwoOinVjPz/N5ZY230omXSgs+/ktThYndTyeLujjGVQy4gsN6dAWYOfgAJjZcvkTJ4V0JMYGXxsOgxrrkidFvAz9pC3P4Q7g9F/mg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Ftng5STj; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Ftng5STj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 13A54C2BCB3; Thu, 14 May 2026 12:22:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778761365; bh=Yqxi9WNOyPgZenBZoE5iwSQ74FymEj/lLJ/BxCqBOGY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Ftng5STjO2s6+iHj2g0I612GVQ3PTkt0X7dfMBm2wU0xYyxE6wGGk9/LI9gfOwYho 6bXMo0/WoehHcZPHcOZBfCvCbhEhmLkvBXA/8UL6yMNClz6D0nIz0wHVH0IC5zbeZ8 Q38TtF+ASMr/NBV1VyczIFxmQjEvwDyhig31vk2oL8Kse+JVgq0jW/uZBqiZYNMxeO U/rqQh68w0grpOhxnwEC4YcpxdgZCY0LzbTEDpXP84zmssvY8oH9V6F+QmfiEuIdbf FwDtcRTz4XajzH2LFo0o96jo4AqxZdOBIVag3BqphmpAzXs9wPzUja0+0wlh4zsxkb IJlz+KY46q5cQ== Date: Thu, 14 May 2026 13:22:40 +0100 From: Lorenzo Stoakes To: ranxiaokai627@163.com Cc: hughd@google.com, baolin.wang@linux.alibaba.com, akpm@linux-foundation.org, leitao@debian.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, ran.xiaokai@zte.com.cn Subject: Re: [PATCH v2 2/2] mm: huge_memory: refactor thpsize_shmem_enabled_show() with helper arrays Message-ID: References: <20260513094508.50888-1-ranxiaokai627@163.com> <20260513094508.50888-2-ranxiaokai627@163.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260513094508.50888-2-ranxiaokai627@163.com> (As I said in the 1/2) Please don't send 2/2 in response to 1/2, and use a cover letter if you send more than 1 patch! On Wed, May 13, 2026 at 09:45:08AM +0000, ranxiaokai627@163.com wrote: > From: Ran Xiaokai > > Replace the hardcoded if/else chain of test_bit() calls and string > literals in thpsize_shmem_enabled_show() with a loop over > huge_shmem_orders_by_mode[] and huge_shmem_enabled_mode_strings[] arrays. > > This makes thpsize_shmem_enabled_show() consistent with > thpsize_shmem_enabled_store() and eliminates duplicated mode name strings. > > Signed-off-by: Ran Xiaokai The logic looks good, I wish we could de-duplicate. But for now maybe better to get this refactored first. So: Reviewed-by: Lorenzo Stoakes > --- > mm/shmem.c | 36 +++++++++++++++++++++++------------- > 1 file changed, 23 insertions(+), 13 deletions(-) > > diff --git a/mm/shmem.c b/mm/shmem.c > index 60cb10854f11..086762e6de71 100644 > --- a/mm/shmem.c > +++ b/mm/shmem.c > @@ -5553,20 +5553,30 @@ static ssize_t thpsize_shmem_enabled_show(struct kobject *kobj, > struct kobj_attribute *attr, char *buf) > { > int order = to_thpsize(kobj)->order; > - const char *output; > - > - if (test_bit(order, &huge_shmem_orders_always)) > - output = "[always] inherit within_size advise never"; > - else if (test_bit(order, &huge_shmem_orders_inherit)) > - output = "always [inherit] within_size advise never"; > - else if (test_bit(order, &huge_shmem_orders_within_size)) > - output = "always inherit [within_size] advise never"; > - else if (test_bit(order, &huge_shmem_orders_madvise)) > - output = "always inherit within_size [advise] never"; > - else > - output = "always inherit within_size advise [never]"; > + int active = HUGE_SHMEM_ENABLED_NEVER; > + int len = 0; > + int i; > + > + for (i = 0; i < ARRAY_SIZE(huge_shmem_orders_by_mode); i++) { > + if (test_bit(order, huge_shmem_orders_by_mode[i])) { > + active = i; > + break; > + } > + } > + > + for (i = 0; i < ARRAY_SIZE(huge_shmem_enabled_mode_strings); i++) { > + if (i == active) > + len += sysfs_emit_at(buf, len, "[%s] ", > + huge_shmem_enabled_mode_strings[i]); > + else > + len += sysfs_emit_at(buf, len, "%s ", > + huge_shmem_enabled_mode_strings[i]); > + } > + > + /* Replace trailing space with newline */ > + buf[len - 1] = '\n'; > > - return sysfs_emit(buf, "%s\n", output); > + return len; > } This is pretty mcuh a one-for-one copy/pasta of defrag_show(), I don't love that we have the exact same code duplicated across two files like that. You could write something like: static ssize_t thp_sysfs_enabled_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf, const char *names, int names_len, const char *orders_by_mode, int orders_by_mode_len, int default_mode) { ... } To abstract it, but that's kind of a horrible signature isn't it? :) Could use a helper struct, but that feels a bit overkill for this hmm... Really I wonder if we shouldn't have this in huge_memory.c anyway, it's a bit of a weird thing to put it in mm/shmem.c, it's more huge pages than shmem imo. Anyway. The logic itself looks fine so LGTM! > > static ssize_t thpsize_shmem_enabled_store(struct kobject *kobj, > -- > 2.25.1 > > Cheers, Lorenzo