All of lore.kernel.org
 help / color / mirror / Atom feed
From: Darren Hart <darren.hart@intel.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Shan Hai <haishan.bai@gmail.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	paulus@samba.org, tglx@linutronix.de, walken@google.com,
	dhowells@redhat.com, cmetcalf@tilera.com, tony.luck@intel.com,
	akpm@linux-foundation.org, linuxppc-dev@lists.ozlabs.org,
	linux-kernel@vger.kernel.org
Subject: Re: [RFC/PATCH] mm/futex: Fix futex writes on archs with SW tracking of dirty & young
Date: Wed, 20 Jul 2011 07:39:40 -0700	[thread overview]
Message-ID: <4E26E8AC.7080407@intel.com> (raw)
In-Reply-To: <1311049762.25044.392.camel@pasglop>

Obviously no objection from the futex side of things, looks good. Couple
nits on the function comment:

On 07/18/2011 09:29 PM, Benjamin Herrenschmidt wrote:
...
> -/**
> +/*
> + * fixup_user_fault() - manually resolve a user page  fault

s/  fault/ fault/

> + * @tsk:	the task_struct to use for page fault accounting, or
> + *		NULL if faults are not to be recorded.
> + * @mm:		mm_struct of target mm
> + * @address:	user address
> + * @fault_flags:flags to pass down to handle_mm_fault()
> + *
> + * This is meant to be called in the specific scenario where for
> + * locking reasons we try to access user memory in atomic context
> + * (within a pagefault_disable() section), this returns -EFAULT,
> + * and we want to resolve the user fault before trying again.
> + *
> + * Typically this is meant to be used by the futex code.
> + *
> + * The main difference with get_user_pages() is that this function
> + * will unconditionally call handle_mm_fault() which will in turn
> + * perform all the necessary SW fixup of the dirty and young bits
> + * in the PTE, while handle_mm_fault() only guarantees to update
> + * these in the struct page.
> + *
> + * This is important for some architectures where those bits also
> + * gate the access permission to the page because their are

s/their/they/

Thanks,

-- 
Darren Hart
Intel Open Source Technology Center
Yocto Project - Linux Kernel

WARNING: multiple messages have this Message-ID (diff)
From: Darren Hart <darren.hart@intel.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: tony.luck@intel.com, Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Shan Hai <haishan.bai@gmail.com>,
	Peter Zijlstra <peterz@infradead.org>,
	linux-kernel@vger.kernel.org, cmetcalf@tilera.com,
	dhowells@redhat.com, paulus@samba.org, tglx@linutronix.de,
	walken@google.com, linuxppc-dev@lists.ozlabs.org,
	akpm@linux-foundation.org
Subject: Re: [RFC/PATCH] mm/futex: Fix futex writes on archs with SW tracking of dirty & young
Date: Wed, 20 Jul 2011 07:39:40 -0700	[thread overview]
Message-ID: <4E26E8AC.7080407@intel.com> (raw)
In-Reply-To: <1311049762.25044.392.camel@pasglop>

Obviously no objection from the futex side of things, looks good. Couple
nits on the function comment:

On 07/18/2011 09:29 PM, Benjamin Herrenschmidt wrote:
...
> -/**
> +/*
> + * fixup_user_fault() - manually resolve a user page  fault

s/  fault/ fault/

> + * @tsk:	the task_struct to use for page fault accounting, or
> + *		NULL if faults are not to be recorded.
> + * @mm:		mm_struct of target mm
> + * @address:	user address
> + * @fault_flags:flags to pass down to handle_mm_fault()
> + *
> + * This is meant to be called in the specific scenario where for
> + * locking reasons we try to access user memory in atomic context
> + * (within a pagefault_disable() section), this returns -EFAULT,
> + * and we want to resolve the user fault before trying again.
> + *
> + * Typically this is meant to be used by the futex code.
> + *
> + * The main difference with get_user_pages() is that this function
> + * will unconditionally call handle_mm_fault() which will in turn
> + * perform all the necessary SW fixup of the dirty and young bits
> + * in the PTE, while handle_mm_fault() only guarantees to update
> + * these in the struct page.
> + *
> + * This is important for some architectures where those bits also
> + * gate the access permission to the page because their are

s/their/they/

Thanks,

-- 
Darren Hart
Intel Open Source Technology Center
Yocto Project - Linux Kernel

  parent reply	other threads:[~2011-07-20 14:39 UTC|newest]

Thread overview: 138+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-07-15  8:07 [PATCH 0/1] Fixup write permission of TLB on powerpc e500 core Shan Hai
2011-07-15  8:07 ` Shan Hai
2011-07-15  8:07 ` [PATCH 1/1] " Shan Hai
2011-07-15  8:07   ` Shan Hai
2011-07-15 10:23   ` Peter Zijlstra
2011-07-15 10:23     ` Peter Zijlstra
2011-07-15 15:18     ` Shan Hai
2011-07-15 15:18       ` Shan Hai
2011-07-15 15:24       ` Peter Zijlstra
2011-07-15 15:24         ` Peter Zijlstra
2011-07-16 15:36         ` Shan Hai
2011-07-16 15:36           ` Shan Hai
2011-07-16 14:50     ` Shan Hai
2011-07-16 14:50       ` Shan Hai
2011-07-16 23:49       ` Benjamin Herrenschmidt
2011-07-16 23:49         ` Benjamin Herrenschmidt
2011-07-17  9:38         ` Peter Zijlstra
2011-07-17  9:38           ` Peter Zijlstra
2011-07-17 14:29           ` Benjamin Herrenschmidt
2011-07-17 14:29             ` Benjamin Herrenschmidt
2011-07-17 23:14             ` Benjamin Herrenschmidt
2011-07-17 23:14               ` Benjamin Herrenschmidt
2011-07-18  3:53               ` Benjamin Herrenschmidt
2011-07-18  3:53                 ` Benjamin Herrenschmidt
2011-07-18  4:02                 ` Benjamin Herrenschmidt
2011-07-18  4:02                   ` Benjamin Herrenschmidt
2011-07-18  4:01               ` Benjamin Herrenschmidt
2011-07-18  4:01                 ` Benjamin Herrenschmidt
2011-07-18  6:48                 ` Shan Hai
2011-07-18  6:48                   ` Shan Hai
2011-07-18  7:01                   ` Benjamin Herrenschmidt
2011-07-18  7:01                     ` Benjamin Herrenschmidt
2011-07-18  7:26                     ` Shan Hai
2011-07-18  7:26                       ` Shan Hai
2011-07-18  7:36                       ` Benjamin Herrenschmidt
2011-07-18  7:36                         ` Benjamin Herrenschmidt
2011-07-18  7:50                         ` Shan Hai
2011-07-18  7:50                           ` Shan Hai
2011-07-19  3:30                         ` Shan Hai
2011-07-19  3:30                           ` Shan Hai
2011-07-19  4:20                           ` Benjamin Herrenschmidt
2011-07-19  4:20                             ` Benjamin Herrenschmidt
2011-07-19  4:29                           ` [RFC/PATCH] mm/futex: Fix futex writes on archs with SW tracking of dirty & young Benjamin Herrenschmidt
2011-07-19  4:29                             ` Benjamin Herrenschmidt
2011-07-19  4:55                             ` Shan Hai
2011-07-19  4:55                               ` Shan Hai
2011-07-19  5:17                             ` Shan Hai
2011-07-19  5:17                               ` Shan Hai
2011-07-19  5:24                               ` Benjamin Herrenschmidt
2011-07-19  5:24                                 ` Benjamin Herrenschmidt
2011-07-19  5:38                                 ` Shan Hai
2011-07-19  5:38                                   ` Shan Hai
2011-07-19  7:46                                   ` Benjamin Herrenschmidt
2011-07-19  7:46                                     ` Benjamin Herrenschmidt
2011-07-19  8:24                                     ` Shan Hai
2011-07-19  8:24                                       ` Shan Hai
2011-07-19  8:26                                       ` [RFC/PATCH] mm/futex: Fix futex writes on archs with SW trackingof " David Laight
2011-07-19  8:26                                         ` David Laight
2011-07-19  8:45                                         ` Benjamin Herrenschmidt
2011-07-19  8:45                                           ` Benjamin Herrenschmidt
2011-07-19  8:45                                         ` Shan Hai
2011-07-19  8:45                                           ` Shan Hai
2011-07-19 11:10                             ` [RFC/PATCH] mm/futex: Fix futex writes on archs with SW tracking of " Peter Zijlstra
2011-07-19 11:10                               ` Peter Zijlstra
2011-07-20 14:39                             ` Darren Hart [this message]
2011-07-20 14:39                               ` Darren Hart
2011-07-21 22:36                             ` Andrew Morton
2011-07-21 22:36                               ` Andrew Morton
2011-07-21 22:52                               ` Benjamin Herrenschmidt
2011-07-21 22:52                                 ` Benjamin Herrenschmidt
2011-07-21 22:57                                 ` Benjamin Herrenschmidt
2011-07-21 22:57                                   ` Benjamin Herrenschmidt
2011-07-21 22:59                                 ` Andrew Morton
2011-07-21 22:59                                   ` Andrew Morton
2011-07-22  1:40                                   ` Benjamin Herrenschmidt
2011-07-22  1:40                                     ` Benjamin Herrenschmidt
2011-07-22  1:54                                   ` Shan Hai
2011-07-22  1:54                                     ` Shan Hai
2011-07-27  6:50                             ` Mike Frysinger
2011-07-27  6:50                               ` Mike Frysinger
2011-07-27  7:58                               ` Benjamin Herrenschmidt
2011-07-27  7:58                                 ` Benjamin Herrenschmidt
2011-07-27  8:59                                 ` Peter Zijlstra
2011-07-27  8:59                                   ` Peter Zijlstra
2011-07-27 10:09                                 ` David Howells
2011-07-27 10:09                                   ` David Howells
2011-07-27 10:17                                   ` Peter Zijlstra
2011-07-27 10:17                                     ` Peter Zijlstra
2011-07-27 10:20                                     ` Benjamin Herrenschmidt
2011-07-27 10:20                                       ` Benjamin Herrenschmidt
2011-07-28  0:12                                       ` Mike Frysinger
2011-07-28  0:12                                         ` Mike Frysinger
2011-08-08  2:31                                     ` Mike Frysinger
2011-08-08  2:31                                       ` Mike Frysinger
2011-07-28 10:55                                   ` David Howells
2011-07-28 10:55                                     ` David Howells
2011-07-17 11:02         ` [PATCH 1/1] Fixup write permission of TLB on powerpc e500 core Peter Zijlstra
2011-07-17 11:02           ` Peter Zijlstra
2011-07-17 13:33           ` Shan Hai
2011-07-17 13:33             ` Shan Hai
2011-07-17 14:48             ` Benjamin Herrenschmidt
2011-07-17 14:48               ` Benjamin Herrenschmidt
2011-07-17 15:40               ` Shan Hai
2011-07-17 15:40                 ` Shan Hai
2011-07-17 22:34                 ` Benjamin Herrenschmidt
2011-07-17 22:34                   ` Benjamin Herrenschmidt
2011-07-17 14:34           ` Benjamin Herrenschmidt
2011-07-17 14:34             ` Benjamin Herrenschmidt
2011-07-15  8:20 ` [PATCH 0/1] " Peter Zijlstra
2011-07-15  8:20   ` Peter Zijlstra
2011-07-15  8:38   ` MailingLists
2011-07-15  8:38     ` MailingLists
2011-07-15  8:44     ` Peter Zijlstra
2011-07-15  8:44       ` Peter Zijlstra
2011-07-15  9:08       ` Shan Hai
2011-07-15  9:08         ` Shan Hai
2011-07-15  9:12         ` Benjamin Herrenschmidt
2011-07-15  9:12           ` Benjamin Herrenschmidt
2011-07-15  9:50         ` Peter Zijlstra
2011-07-15  9:50           ` Peter Zijlstra
2011-07-15 10:06           ` Shan Hai
2011-07-15 10:06             ` Shan Hai
2011-07-15 10:32             ` David Laight
2011-07-15 10:32               ` David Laight
2011-07-15 10:39               ` Peter Zijlstra
2011-07-15 10:39                 ` Peter Zijlstra
2011-07-15 15:32               ` Shan Hai
2011-07-15 15:32                 ` Shan Hai
2011-07-16  0:20                 ` Benjamin Herrenschmidt
2011-07-16  0:20                   ` Benjamin Herrenschmidt
2011-07-16 15:03                   ` Shan Hai
2011-07-16 15:03                     ` Shan Hai
2011-07-15 23:47               ` Benjamin Herrenschmidt
2011-07-15 23:47                 ` Benjamin Herrenschmidt
2011-07-15  9:07     ` Benjamin Herrenschmidt
2011-07-15  9:07       ` Benjamin Herrenschmidt
2011-07-15  9:05   ` Benjamin Herrenschmidt
2011-07-15  9:05     ` Benjamin Herrenschmidt

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=4E26E8AC.7080407@intel.com \
    --to=darren.hart@intel.com \
    --cc=a.p.zijlstra@chello.nl \
    --cc=akpm@linux-foundation.org \
    --cc=benh@kernel.crashing.org \
    --cc=cmetcalf@tilera.com \
    --cc=dhowells@redhat.com \
    --cc=haishan.bai@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=paulus@samba.org \
    --cc=peterz@infradead.org \
    --cc=tglx@linutronix.de \
    --cc=tony.luck@intel.com \
    --cc=walken@google.com \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.