From: Oleg Nesterov <oleg@redhat.com>
To: Kees Cook <keescook@chromium.org>
Cc: Alex Thorlton <athorlton@sgi.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
LKML <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
Mel Gorman <mgorman@suse.de>, Rik van Riel <riel@redhat.com>,
Johannes Weiner <hannes@cmpxchg.org>,
"Eric W. Biederman" <ebiederm@xmission.com>,
Sedat Dilek <sedat.dilek@gmail.com>,
Frederic Weisbecker <fweisbec@gmail.com>,
Dave Jones <davej@redhat.com>,
Michael Kerrisk <mtk.manpages@gmail.com>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
David Howells <dhowells@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Al Viro <viro@zeniv.linux.org.uk>,
Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
Robin Holt <holt@sgi.com>
Subject: Re: [PATCH] Add per-process flag to control thp
Date: Sun, 4 Aug 2013 16:19:28 +0200 [thread overview]
Message-ID: <20130804141928.GA17935@redhat.com> (raw)
In-Reply-To: <CAGXu5j+d3fzKWNtmPF9tyMg7PzHsKWQZkhu5tFaThLTZue=3JQ@mail.gmail.com>
On 08/03, Kees Cook wrote:
>
> On Fri, Aug 2, 2013 at 1:34 PM, Alex Thorlton <athorlton@sgi.com> wrote:
> >
> >> And I think thp_disabled should be reset to 0 on exec.
> >
> > The main purpose for this getting carried down from the parent process
> > is that we'd like to be able to have a userland program set this flag on
> > itself, and then spawn off children who will also carry the flag.
> > This allows us to set the flag for programs where we're unable to modify
> > the code, thus resolving the issues detailed above.
>
> This could be done with LD_PRELOAD for uncontrolled binaries. Though
> it does seem sensible to make it act like most personality flags do
> (i.e. inherited).
It is only inheritable if the process is single-threaded.
And even if it is single-threaded I can't understand how it can really
help.
OK, transparent_hugepage_enabled() checks ->thp_disabled, but this is
the fault path. But this flag can't hide the task from khugepaged and
collapse_huge_page ?
I still think this should be mm flag. And we have MMF_INIT_MASK, it
can be inheritable.
Oleg.
next prev parent reply other threads:[~2013-08-04 14:25 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-02 19:46 [PATCH] Add per-process flag to control thp Alex Thorlton
2013-08-02 19:53 ` Dave Jones
2013-08-02 20:00 ` Alex Thorlton
2013-08-02 20:13 ` Kirill A. Shutemov
2013-08-02 20:34 ` Alex Thorlton
2013-08-02 23:59 ` Kirill A. Shutemov
2013-08-03 19:35 ` Kees Cook
2013-08-04 14:19 ` Oleg Nesterov [this message]
2013-08-05 2:36 ` Andi Kleen
2013-08-05 15:07 ` Alex Thorlton
2013-08-16 14:33 ` [PATCH 0/8] " Alex Thorlton
2013-08-16 14:33 ` [PATCH 1/8] THP: Use real address for NUMA policy Alex Thorlton
2013-08-16 17:53 ` Dave Hansen
2013-08-16 18:17 ` Alex Thorlton
2013-08-16 18:52 ` Kirill A. Shutemov
2013-08-27 16:50 ` Alex Thorlton
2013-08-27 17:01 ` Robin Holt
2013-09-04 15:43 ` Alex Thorlton
2013-09-04 17:15 ` Alex Thorlton
2013-09-05 11:15 ` Ingo Molnar
2013-09-09 16:48 ` Alex Thorlton
2013-09-10 7:47 ` [benchmark] THP performance testcase Ingo Molnar
2013-09-13 13:06 ` [PATCH 0/9] split page table lock for PMD tables Kirill A. Shutemov
2013-09-13 13:06 ` [PATCH 1/9] mm: rename SPLIT_PTLOCKS to SPLIT_PTE_PTLOCKS Kirill A. Shutemov
2013-09-13 15:20 ` Dave Hansen
2013-09-13 13:06 ` [PATCH 2/9] mm: convert mm->nr_ptes to atomic_t Kirill A. Shutemov
2013-09-13 13:06 ` [PATCH 3/9] mm: introduce api for split page table lock for PMD level Kirill A. Shutemov
2013-09-13 13:19 ` Peter Zijlstra
2013-09-13 14:22 ` Kirill A. Shutemov
2013-09-13 13:06 ` [PATCH 4/9] mm, thp: change pmd_trans_huge_lock() to return taken lock Kirill A. Shutemov
2013-09-13 13:06 ` [PATCH 5/9] mm, thp: move ptl taking inside page_check_address_pmd() Kirill A. Shutemov
2013-09-13 13:06 ` [PATCH 6/9] mm, thp: do not access mm->pmd_huge_pte directly Kirill A. Shutemov
2013-09-13 13:06 ` [PATCH 7/9] mm: convent the rest to new page table lock api Kirill A. Shutemov
2013-09-13 13:06 ` [PATCH 8/9] mm: implement split page table lock for PMD level Kirill A. Shutemov
2013-09-13 13:24 ` Peter Zijlstra
2013-09-13 14:25 ` Kirill A. Shutemov
2013-09-13 14:52 ` Peter Zijlstra
2013-09-13 13:36 ` Peter Zijlstra
2013-09-13 14:25 ` Kirill A. Shutemov
2013-09-13 15:45 ` Naoya Horiguchi
2013-09-13 19:57 ` Dave Hansen
2013-09-13 13:06 ` [PATCH 9/9] x86, mm: enable " Kirill A. Shutemov
[not found] ` <20130828091814.GA13681@gmail.com>
2013-08-28 9:32 ` [PATCH 1/8] THP: Use real address for NUMA policy Peter Zijlstra
2013-08-16 19:46 ` Peter Zijlstra
2013-08-16 19:49 ` Alex Thorlton
2013-08-16 14:33 ` [PATCH 2/8] mm: make clear_huge_page tolerate non aligned address Alex Thorlton
2013-08-16 14:33 ` [PATCH 3/8] THP: Pass real, not rounded, address to clear_huge_page Alex Thorlton
2013-08-16 14:34 ` [PATCH 4/8] x86: Add clear_page_nocache Alex Thorlton
2013-08-16 14:34 ` [PATCH 5/8] mm: make clear_huge_page cache clear only around the fault address Alex Thorlton
2013-08-16 18:02 ` Dave Hansen
2013-08-16 14:34 ` [PATCH 6/8] x86: switch the 64bit uncached page clear to SSE/AVX v2 Alex Thorlton
2013-08-16 14:34 ` [PATCH 7/8] remove KM_USER0 from kmap_atomic call Alex Thorlton
2013-08-16 14:34 ` [PATCH 8/8] fix up references to kernel_fpu_begin/end Alex Thorlton
2013-08-16 14:47 ` [PATCH 0/8] Re: [PATCH] Add per-process flag to control thp Peter Zijlstra
2013-08-16 15:04 ` Alex Thorlton
2013-08-04 14:44 ` Rasmus Villemoes
2013-08-28 13:56 ` Andrea Arcangeli
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