From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-132.freemail.mail.aliyun.com (out30-132.freemail.mail.aliyun.com [115.124.30.132]) (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 D9EE8139CEB for ; Wed, 24 Apr 2024 03:48:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.132 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713930514; cv=none; b=SDg3Bshqg4Q86iqezbpdbXb+o2O9pNELvq3s0HzikiS527TzkaEb4CQyABDPwxtol/NAK2ptDT8pPe0pv0o5Jo6AEmU25FOJV7z16F2unTCcSXFZyroxPbXVyzWs88YopLk9Ji7/5+DKtP9P4wm/WyOP6mQz8qSRPbETQ01STBY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713930514; c=relaxed/simple; bh=PVtuPBs5eGsKOVbPHJb9cT/9z2T7nRtaF3A2ljCMW4M=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=JrHssoXRJo8lH8LWIIG0z/6z/4vWBX6wMlWlID0M9JTiHKKvWN1fFubPn2kKyrQsQvGcFboc2WcTaOms1JPccaxb91Pv+dVmpvLrUKNBqTY+p1ieW5SzMmBM+ojMW0yMRi3cymDDPqdy3SgRcycHIzAtKyrY2+nQvfQ41g+lMEo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=XZdKxFjH; arc=none smtp.client-ip=115.124.30.132 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="XZdKxFjH" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1713930508; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=i+3UguXcbzDLCETmEYwCVhpdB29rZwyImQLfXWWDzHk=; b=XZdKxFjHn1SsTcDMj04oKltGqSP3EfVbmwcRsw/WndNlFTHaWJo9iDffSvWysjFG4bF/5FiHQYihPDRBo8ZTVIbtIUJq48NVhIhokfONyGTchyCAgq60As2atZtYe1rOi45hC90fsmmMXzOyWTWftKWHEXAv9Nk9+uRVsrqM0bU= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R321e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033022160150;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=12;SR=0;TI=SMTPD_---0W5AlpPR_1713930504; Received: from 30.97.56.58(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0W5AlpPR_1713930504) by smtp.aliyun-inc.com; Wed, 24 Apr 2024 11:48:26 +0800 Message-ID: <8e0a34df-3a02-40a6-a09d-3b4a25ec7fcf@linux.alibaba.com> Date: Wed, 24 Apr 2024 11:48:24 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH 5/5] mm: shmem: add anonymous share mTHP counters To: Ryan Roberts , Barry Song <21cnbao@gmail.com> Cc: akpm@linux-foundation.org, hughd@google.com, willy@infradead.org, david@redhat.com, wangkefeng.wang@huawei.com, ying.huang@intel.com, shy828301@gmail.com, ziy@nvidia.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <05d0096e4ec3e572d1d52d33a31a661321ac1551.1713755580.git.baolin.wang@linux.alibaba.com> <3045341d-06c2-4fdb-88a1-3f0d473f99ee@linux.alibaba.com> <5f147c9d-ba00-4757-b88e-38b45fffb8d3@arm.com> From: Baolin Wang In-Reply-To: <5f147c9d-ba00-4757-b88e-38b45fffb8d3@arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 2024/4/23 19:39, Ryan Roberts wrote: > On 23/04/2024 02:46, Baolin Wang wrote: >> >> >> On 2024/4/23 09:17, Barry Song wrote: >>> On Mon, Apr 22, 2024 at 3:03 PM Baolin Wang >>> wrote: >>>> >>>> Signed-off-by: Baolin Wang >>>> --- >>>>   include/linux/huge_mm.h | 2 ++ >>>>   mm/huge_memory.c        | 4 ++++ >>>>   mm/shmem.c              | 5 ++++- >>>>   3 files changed, 10 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h >>>> index 26b6fa98d8ac..67b9c1acad31 100644 >>>> --- a/include/linux/huge_mm.h >>>> +++ b/include/linux/huge_mm.h >>>> @@ -270,6 +270,8 @@ enum mthp_stat_item { >>>>          MTHP_STAT_ANON_SWPOUT, >>>>          MTHP_STAT_ANON_SWPOUT_FALLBACK, >>>>          MTHP_STAT_ANON_SWPIN_REFAULT, >>>> +       MTHP_STAT_SHMEM_ANON_ALLOC, >>>> +       MTHP_STAT_SHMEM_ANON_ALLOC_FALLBACK, >>> >>> not quite sure about this. for 2MB pmd-mapped THP shmem, we count them >>> as FILE_THP. >>> here we are counting as SHMEM_ANON. To me, SHMEM_ANON is more correct but >>> it doesn't align with pmd-mapped THP. David, Ryan, what do you think? >> >> Thanks for reviewing. >> >> IMO, I think both approaches are acceptable, which also reflects the dual nature >> of anonymous shared pages: on the one hand they are anonymous pages, and on the >> other hand, they are backed by a pseudo file. From the user's perspective, I >> prefer to use the term "anonymous shmem", which can be distinguished from the >> real file-backed THP. >> >> Anyway, let's see what others think. > > From a quick look at the code, it looks like the shmem alloc/fallback/charge > events are all lumped in with FILE_THP. But the instantaneous "how many are > allocated" and "how many are mapped" have their own NR_SHMEM_THPS and > NR_SHMEM_PMDMAPPED counters? So its a bit inconsistent today. > > My preference would be to add these to be consistent with the anon stats: > > MTHP_STAT_SHMEM_FAULT_ALLOC, > MTHP_STAT_SHMEM_FAULT_FALLBACK, > MTHP_STAT_SHMEM_FAULT_FALLBACK_CHARGE, > > But it looks like these aren't always allocated due to faults? So perhaps: > > MTHP_STAT_SHMEM_ALLOC, > MTHP_STAT_SHMEM_FALLBACK, > MTHP_STAT_SHMEM_FALLBACK_CHARGE, This looks good to me. > If I've understood the code correctly (I know nothing about shmem), the > allocation can be for both mmap(SHARED|ANON) and for tmpfs? So "SHMEM_ANON" This is allowed, but the 'fd' for tmpfs will be ignored (see ksys_mmap_pgoff()), which is same with anonymous shmem. > probably isn't quite right? > > >> >>>>          __MTHP_STAT_COUNT >>>>   }; >>>> >>>> diff --git a/mm/huge_memory.c b/mm/huge_memory.c >>>> index 9e52c0db7580..dc15240c1ab3 100644 >>>> --- a/mm/huge_memory.c >>>> +++ b/mm/huge_memory.c >>>> @@ -557,6 +557,8 @@ DEFINE_MTHP_STAT_ATTR(anon_alloc_fallback, >>>> MTHP_STAT_ANON_ALLOC_FALLBACK); >>>>   DEFINE_MTHP_STAT_ATTR(anon_swpout, MTHP_STAT_ANON_SWPOUT); >>>>   DEFINE_MTHP_STAT_ATTR(anon_swpout_fallback, MTHP_STAT_ANON_SWPOUT_FALLBACK); >>>>   DEFINE_MTHP_STAT_ATTR(anon_swpin_refault, MTHP_STAT_ANON_SWPIN_REFAULT); >>>> +DEFINE_MTHP_STAT_ATTR(shmem_anon_alloc, MTHP_STAT_SHMEM_ANON_ALLOC); >>>> +DEFINE_MTHP_STAT_ATTR(shmem_anon_alloc_fallback, >>>> MTHP_STAT_SHMEM_ANON_ALLOC_FALLBACK); >>>> >>>>   static struct attribute *stats_attrs[] = { >>>>          &anon_alloc_attr.attr, >>>> @@ -564,6 +566,8 @@ static struct attribute *stats_attrs[] = { >>>>          &anon_swpout_attr.attr, >>>>          &anon_swpout_fallback_attr.attr, >>>>          &anon_swpin_refault_attr.attr, >>>> +       &shmem_anon_alloc_attr.attr, >>>> +       &shmem_anon_alloc_fallback_attr.attr, >>>>          NULL, >>>>   }; >>>> >>>> diff --git a/mm/shmem.c b/mm/shmem.c >>>> index 8b009e7040b2..4a0aa75ab29c 100644 >>>> --- a/mm/shmem.c >>>> +++ b/mm/shmem.c >>>> @@ -1706,11 +1706,14 @@ static struct folio *shmem_alloc_and_add_folio(struct >>>> vm_fault *vmf, >>>>                          pages = 1 << order; >>>>                          index = round_down(index, pages); >>>>                          folio = shmem_alloc_hugefolio(gfp, info, index, order); >>>> -                       if (folio) >>>> +                       if (folio) { >>>> +                               count_mthp_stat(order, >>>> MTHP_STAT_SHMEM_ANON_ALLOC); > > is there any reason why this can't go next to the existing PMD-size stat? No, will move to the existing PMD-size stat.