From: Mel Gorman <mgorman@suse.de>
To: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Rik van Riel <riel@redhat.com>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Andrea Arcangeli <aarcange@redhat.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Hugh Dickins <hughd@google.com>,
Thomas Gleixner <tglx@linutronix.de>,
Andrew Morton <akpm@linux-foundation.org>,
Linux-MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 06/43] mm: numa: Make pte_numa() and pmd_numa() a generic implementation
Date: Fri, 16 Nov 2012 18:55:17 +0000 [thread overview]
Message-ID: <20121116185517.GH8218@suse.de> (raw)
In-Reply-To: <20121116180404.GA4728@gmail.com>
On Fri, Nov 16, 2012 at 07:04:04PM +0100, Ingo Molnar wrote:
>
> * Mel Gorman <mgorman@suse.de> wrote:
>
> > That said, your approach just ends up being heavier. [...]
>
> Well, it's more fundamental than just whether to inline or not
> (which I think should be a separate optimization and I won't
> object to two-instruction variants the slightest) - but you
> ended up open-coding change_protection()
> via:
>
> change_prot_numa_range() et al
>
> which is a far bigger problem...
>
> Do you have valid technical arguments in favor of that
> duplication?
>
No, I don't and I have not claimed that it *has* to exist. In fact I've
said multiple times than I can convert to change_protection as long as
_PAGE_NUMA == _PAGE_NONE. This initial step was to build the list
of requirements without worrying about breaking existing users of
change_protection. Now that I know what the requirements are, I can convert.
> If you just embrace the PROT_NONE reuse approach of numa/core
> then 90% of the differences in your tree will disappear and
> you'll have a code base very close to where numa/core was 3
> weeks ago already, modulo a handful of renames.
>
Pointed out the missing parts in another mail already -- MIGRATE_FAULT,
pmd handling in batch, stats and a logical progression from a simple to
a complex policy.
> It's not like PROT_NONE will go away anytime soon.
>
> PROT_NONE is available on every architecture, and we use the
> exact semantics of it in the scheduler, we just happen to drive
> it from a special worklet instead of a syscall, and happen to
> have a callback to the faults when they happen...
>
> Please stay open to that approach.
>
I will.
If anything, me switching to prot_none would be a hell of a lot easier
than you trying to pick up the bits you're missing. I'll take a look
Monday and see what falls out.
--
Mel Gorman
SUSE Labs
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WARNING: multiple messages have this Message-ID (diff)
From: Mel Gorman <mgorman@suse.de>
To: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Rik van Riel <riel@redhat.com>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Andrea Arcangeli <aarcange@redhat.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Hugh Dickins <hughd@google.com>,
Thomas Gleixner <tglx@linutronix.de>,
Andrew Morton <akpm@linux-foundation.org>,
Linux-MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 06/43] mm: numa: Make pte_numa() and pmd_numa() a generic implementation
Date: Fri, 16 Nov 2012 18:55:17 +0000 [thread overview]
Message-ID: <20121116185517.GH8218@suse.de> (raw)
In-Reply-To: <20121116180404.GA4728@gmail.com>
On Fri, Nov 16, 2012 at 07:04:04PM +0100, Ingo Molnar wrote:
>
> * Mel Gorman <mgorman@suse.de> wrote:
>
> > That said, your approach just ends up being heavier. [...]
>
> Well, it's more fundamental than just whether to inline or not
> (which I think should be a separate optimization and I won't
> object to two-instruction variants the slightest) - but you
> ended up open-coding change_protection()
> via:
>
> change_prot_numa_range() et al
>
> which is a far bigger problem...
>
> Do you have valid technical arguments in favor of that
> duplication?
>
No, I don't and I have not claimed that it *has* to exist. In fact I've
said multiple times than I can convert to change_protection as long as
_PAGE_NUMA == _PAGE_NONE. This initial step was to build the list
of requirements without worrying about breaking existing users of
change_protection. Now that I know what the requirements are, I can convert.
> If you just embrace the PROT_NONE reuse approach of numa/core
> then 90% of the differences in your tree will disappear and
> you'll have a code base very close to where numa/core was 3
> weeks ago already, modulo a handful of renames.
>
Pointed out the missing parts in another mail already -- MIGRATE_FAULT,
pmd handling in batch, stats and a logical progression from a simple to
a complex policy.
> It's not like PROT_NONE will go away anytime soon.
>
> PROT_NONE is available on every architecture, and we use the
> exact semantics of it in the scheduler, we just happen to drive
> it from a special worklet instead of a syscall, and happen to
> have a callback to the faults when they happen...
>
> Please stay open to that approach.
>
I will.
If anything, me switching to prot_none would be a hell of a lot easier
than you trying to pick up the bits you're missing. I'll take a look
Monday and see what falls out.
--
Mel Gorman
SUSE Labs
next prev parent reply other threads:[~2012-11-16 18:55 UTC|newest]
Thread overview: 124+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-16 11:22 [RFC PATCH 00/43] Automatic NUMA Balancing V3 Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 01/43] mm: compaction: Move migration fail/success stats to migrate.c Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 02/43] mm: migrate: Add a tracepoint for migrate_pages Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 03/43] mm: compaction: Add scanned and isolated counters for compaction Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 04/43] mm: numa: define _PAGE_NUMA Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 05/43] mm: numa: pte_numa() and pmd_numa() Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 06/43] mm: numa: Make pte_numa() and pmd_numa() a generic implementation Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 14:09 ` Rik van Riel
2012-11-16 14:09 ` Rik van Riel
2012-11-16 14:41 ` Mel Gorman
2012-11-16 14:41 ` Mel Gorman
2012-11-16 15:32 ` Linus Torvalds
2012-11-16 15:32 ` Linus Torvalds
2012-11-16 16:08 ` Ingo Molnar
2012-11-16 16:08 ` Ingo Molnar
2012-11-16 16:56 ` Mel Gorman
2012-11-16 16:56 ` Mel Gorman
2012-11-16 17:12 ` Ingo Molnar
2012-11-16 17:12 ` Ingo Molnar
2012-11-16 17:48 ` Mel Gorman
2012-11-16 17:48 ` Mel Gorman
2012-11-16 18:04 ` Ingo Molnar
2012-11-16 18:04 ` Ingo Molnar
2012-11-16 18:55 ` Mel Gorman [this message]
2012-11-16 18:55 ` Mel Gorman
2012-11-16 17:26 ` Rik van Riel
2012-11-16 17:26 ` Rik van Riel
2012-11-16 17:37 ` Ingo Molnar
2012-11-16 17:37 ` Ingo Molnar
2012-11-16 18:44 ` Mel Gorman
2012-11-16 18:44 ` Mel Gorman
2012-11-16 16:19 ` Mel Gorman
2012-11-16 16:19 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 07/43] mm: numa: Support NUMA hinting page faults from gup/gup_fast Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 14:09 ` Rik van Riel
2012-11-16 14:09 ` Rik van Riel
2012-11-16 11:22 ` [PATCH 08/43] mm: numa: split_huge_page: transfer the NUMA type from the pmd to the pte Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 09/43] mm: numa: Create basic numa page hinting infrastructure Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 10/43] mm: mempolicy: Make MPOL_LOCAL a real policy Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 11/43] mm: mempolicy: Add MPOL_MF_NOOP Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 12/43] mm: mempolicy: Check for misplaced page Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 13/43] mm: migrate: Introduce migrate_misplaced_page() Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-19 19:44 ` [tip:numa/core] mm/migration: Improve migrate_misplaced_page() tip-bot for Mel Gorman
2012-11-19 19:44 ` tip-bot for Mel Gorman
2012-11-16 11:22 ` [PATCH 14/43] mm: mempolicy: Use _PAGE_NUMA to migrate pages Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 16:08 ` Rik van Riel
2012-11-16 16:08 ` Rik van Riel
2012-11-16 11:22 ` [PATCH 15/43] mm: mempolicy: Add MPOL_MF_LAZY Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 16/43] mm: mempolicy: Hide MPOL_NOOP and MPOL_MF_LAZY from userspace for now Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 16:22 ` Rik van Riel
2012-11-16 16:22 ` Rik van Riel
2012-11-16 11:22 ` [PATCH 17/43] sched, mm, x86: Add the ARCH_SUPPORTS_NUMA_BALANCING flag Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 18/43] mm: numa: Add fault driven placement and migration Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 19/43] mm: numa: Avoid double faulting after migrating misplaced page Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 20/43] mm: sched: numa: Implement constant, per task Working Set Sampling (WSS) rate Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 21/43] sched, numa, mm: Count WS scanning against present PTEs, not virtual memory ranges Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 22/43] mm: sched: numa: Implement slow start for working set sampling Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 23/43] mm: numa: Add pte updates, hinting and migration stats Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 24/43] mm: numa: Migrate on reference policy Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 25/43] mm: numa: Migrate pages handled during a pmd_numa hinting fault Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 26/43] mm: numa: Only mark a PMD pmd_numa if the pages are all on the same node Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 27/43] mm: numa: Structures for Migrate On Fault per NUMA migration rate limiting Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 28/43] mm: numa: Rate limit the amount of memory that is migrated between nodes Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 29/43] mm: numa: Rate limit setting of pte_numa if node is saturated Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 30/43] sched: numa: Slowly increase the scanning period as NUMA faults are handled Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 31/43] mm: numa: Introduce last_nid to the page frame Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 32/43] mm: numa: Use a two-stage filter to restrict pages being migrated for unlikely task<->node relationships Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 33/43] x86: mm: only do a local tlb flush in ptep_set_access_flags() Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 34/43] x86: mm: drop TLB flush from ptep_set_access_flags Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 35/43] mm,generic: only flush the local TLB in ptep_set_access_flags Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 36/43] sched: numa: Introduce tsk_home_node() Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 37/43] sched: numa: Make find_busiest_queue() a method Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 38/43] sched: numa: Implement home-node awareness Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 39/43] sched: numa: Introduce per-mm and per-task structures Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 40/43] sched: numa: CPU follows memory Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 41/43] sched: numa: Rename mempolicy to HOME Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 42/43] sched: numa: Consider only one CPU per node for CPU-follows-memory Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 11:22 ` [PATCH 43/43] sched: numa: Increase and decrease a tasks scanning period based on task fault statistics Mel Gorman
2012-11-16 11:22 ` Mel Gorman
2012-11-16 14:56 ` [RFC PATCH 00/43] Automatic NUMA Balancing V3 Mel Gorman
2012-11-16 14:56 ` Mel Gorman
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