linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Linus Torvalds <torvalds@linux-foundation.org>
To: "Luck, Tony" <tony.luck@intel.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>,
	Andrea Arcangeli <aarcange@redhat.com>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
	"kirill.shutemov@linux.intel.com"
	<kirill.shutemov@linux.intel.com>,
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
	"hannes@cmpxchg.org" <hannes@cmpxchg.org>,
	"iamjoonsoo.kim@lge.com" <iamjoonsoo.kim@lge.com>,
	"mgorman@techsingularity.net" <mgorman@techsingularity.net>,
	"vbabka@suse.cz" <vbabka@suse.cz>,
	"mhocko@kernel.org" <mhocko@kernel.org>,
	"hillf.zj@alibaba-inc.com" <hillf.zj@alibaba-inc.com>,
	"hughd@google.com" <hughd@google.com>,
	"oleg@redhat.com" <oleg@redhat.com>,
	"peterz@infradead.org" <peterz@infradead.org>,
	"riel@redhat.com" <riel@redhat.com>,
	"srikar@linux.vnet.ibm.com" <srikar@linux.vnet.ibm.com>,
	"vdavydov.dev@gmail.com" <vdavydov.dev@gmail.com>,
	"mingo@kernel.org" <mingo@kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	"x86@kernel.org" <x86@kernel.org>
Subject: Re: [mm 4.15-rc8] Random oopses under memory pressure.
Date: Thu, 18 Jan 2018 09:28:48 -0800	[thread overview]
Message-ID: <CA+55aFzviumvZcV4a4ddtLu5T_ibCD_Xia+7W5khY3pMQ--jUA@mail.gmail.com> (raw)
In-Reply-To: <3908561D78D1C84285E8C5FCA982C28F7B3446FC@ORSMSX110.amr.corp.intel.com>

On Thu, Jan 18, 2018 at 9:26 AM, Luck, Tony <tony.luck@intel.com> wrote:
>> Both are real page. But why do you expect pages to be 64-byte alinged?
>> Both are aligned to 64-bit as they suppose to be IIUC.
>
> On a 64-bit kernel sizeof struct page == 64 (after much work by people to
> trim out excess stuff).  So I thought we made sure to align the base address
> of blocks of "struct page" so that every one neatly fits into one cache line.

The bug happens on 32-bit, and a 'struct page' is not 64-byte aligned
there at all.

See my other email about the explanation of why "page1 - page2"
doesn't work when they aren't mutually aligned to the actual size of
the 'struct page'.

             Linus

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

  reply	other threads:[~2018-01-18 17:28 UTC|newest]

Thread overview: 59+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-05 14:45 [x86? mm? fs? 4.15-rc6] Random oopses by simple write under memory pressure Tetsuo Handa
2018-01-09 10:39 ` [mm? 4.15-rc7] " Tetsuo Handa
2018-01-10 11:49   ` [mm? 4.15-rc7] Random oopses " Tetsuo Handa
2018-01-10 12:45     ` Michal Hocko
2018-01-10 13:37       ` Tetsuo Handa
2018-01-11 13:57         ` Michal Hocko
2018-01-11 14:11           ` Tetsuo Handa
2018-01-11 14:21             ` Michal Hocko
2018-01-11 14:37               ` Tetsuo Handa
2018-01-12  1:31               ` [mm " Tetsuo Handa
2018-01-12  1:42                 ` Linus Torvalds
2018-01-12 11:22                   ` Tetsuo Handa
2018-01-14 11:54                     ` Tetsuo Handa
2018-01-15 23:05                       ` Linus Torvalds
2018-01-16  1:15                         ` [mm 4.15-rc8] " Tetsuo Handa
2018-01-16  2:14                           ` Linus Torvalds
2018-01-16  8:06                             ` Dave Hansen
2018-01-16  8:37                               ` Ingo Molnar
2018-01-16 19:30                               ` Linus Torvalds
2018-01-16 17:33                             ` Tetsuo Handa
2018-01-16 19:34                               ` Linus Torvalds
2018-01-17 11:08                                 ` Tetsuo Handa
2018-01-17 21:39                                   ` Linus Torvalds
2018-01-17 21:51                                     ` Linus Torvalds
2018-01-17 22:04                                       ` Dave Hansen
2018-01-17 22:00                                     ` Dave Hansen
2018-01-17 22:15                                       ` Linus Torvalds
2018-01-18  8:12                                   ` Tetsuo Handa
2018-01-18 12:25                                     ` Kirill A. Shutemov
2018-01-18 13:12                                       ` Kirill A. Shutemov
2018-01-18 14:34                                         ` Kirill A. Shutemov
2018-01-18 14:38                                         ` Dave Hansen
2018-01-18 14:45                                           ` Kirill A. Shutemov
2018-01-18 14:51                                             ` Dave Hansen
2018-01-18 16:58                                           ` Linus Torvalds
2018-01-18 14:45                                       ` Dave Hansen
2018-01-18 14:58                                         ` Andrea Arcangeli
2018-01-18 16:56                                           ` Kirill A. Shutemov
2018-01-18 17:26                                             ` Luck, Tony
2018-01-18 17:28                                               ` Linus Torvalds [this message]
2018-01-18 17:26                                             ` Linus Torvalds
2018-01-18 23:49                                               ` Kirill A. Shutemov
2018-01-19 12:55                                                 ` Matthew Wilcox
2018-01-19 18:42                                                   ` Linus Torvalds
2018-01-19 22:12                                                     ` Al Viro
2018-01-19 22:53                                                       ` Linus Torvalds
2018-01-20  2:02                                                         ` Al Viro
2018-01-20  5:24                                                           ` Al Viro
2018-01-20  9:38                                                             ` Luc Van Oostenryck
2018-01-18 15:40                                         ` Kirill A. Shutemov
2018-01-18 17:22                                           ` Michal Hocko
2018-01-19 10:02                                             ` Kirill A. Shutemov
2018-01-19 10:33                                               ` Michal Hocko
2018-01-19 11:49                                                 ` Kirill A. Shutemov
2018-01-19 12:07                                                   ` Michal Hocko
2018-01-19 12:30                                                     ` Kirill A. Shutemov
2018-01-19  2:01                                           ` Tetsuo Handa
2018-01-11 18:11             ` [mm? 4.15-rc7] " Linus Torvalds
2018-01-11 20:59               ` Tetsuo Handa

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=CA+55aFzviumvZcV4a4ddtLu5T_ibCD_Xia+7W5khY3pMQ--jUA@mail.gmail.com \
    --to=torvalds@linux-foundation.org \
    --cc=aarcange@redhat.com \
    --cc=akpm@linux-foundation.org \
    --cc=dave.hansen@linux.intel.com \
    --cc=hannes@cmpxchg.org \
    --cc=hillf.zj@alibaba-inc.com \
    --cc=hughd@google.com \
    --cc=iamjoonsoo.kim@lge.com \
    --cc=kirill.shutemov@linux.intel.com \
    --cc=kirill@shutemov.name \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mgorman@techsingularity.net \
    --cc=mhocko@kernel.org \
    --cc=mingo@kernel.org \
    --cc=oleg@redhat.com \
    --cc=penguin-kernel@i-love.sakura.ne.jp \
    --cc=peterz@infradead.org \
    --cc=riel@redhat.com \
    --cc=srikar@linux.vnet.ibm.com \
    --cc=tony.luck@intel.com \
    --cc=vbabka@suse.cz \
    --cc=vdavydov.dev@gmail.com \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).