From: Andi Kleen <andi@firstfloor.org>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>, Yinghai Lu <yhlu.kernel@gmail.com>,
Arjan van de Ven <arjan@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Suresh Siddha <suresh.b.siddha@intel.com>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCh] x86: overmapped fix when 4K pages on tail - 64bit
Date: Mon, 14 Jul 2008 08:39:55 +0200 [thread overview]
Message-ID: <487AF4BB.6050805@firstfloor.org> (raw)
In-Reply-To: <487A9804.8090307@zytor.com>
H. Peter Anvin wrote:
> Andi Kleen wrote:
>>
>> First I was only commenting on one specific patch, nothing more.
>>
>> My point is full rounding to 4K on all corners is wasteful because the
>> CPUs have to handle that case anyways and every split costs precious
>> TLB entries in direct mapping accesses.
>>
>
> Well, the CPU *does* handle them... by splitting the larger pages into
> smaller pages. They still end up in the small-page TLB, so there is no
> real difference if done in the CPU or in software.
There's actually a difference in some cases, but that's a different
issue.
Only when the hole is a real hole. But when it's just some firmware
area or similar that's not needed.
> Memory state transitions are (fortunately) relatively rare and
> long-lived,
That's not true today with several 3d driver setups. Also in general
I would expect more PAT use in the future and that is usually a split.
-Andi
next prev parent reply other threads:[~2008-07-14 6:40 UTC|newest]
Thread overview: 84+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-07-08 8:41 [PATCH] x86: introduce page_size_mask for 64bit Yinghai Lu
2008-07-08 8:43 ` [PATCH] x86: not overmap than end in init_memory_mapping - 64bit Yinghai Lu
2008-07-09 7:38 ` Ingo Molnar
2008-07-09 8:34 ` Ingo Molnar
2008-07-09 8:37 ` Yinghai Lu
2008-07-09 8:46 ` Ingo Molnar
2008-07-09 8:58 ` Yinghai Lu
2008-07-09 10:01 ` Yinghai Lu
2008-07-09 10:30 ` Ingo Molnar
2008-07-09 8:45 ` Ingo Molnar
2008-07-10 3:15 ` [PATCh] x86: overmapped fix when 4K pages on tail " Yinghai Lu
2008-07-10 3:16 ` [PATCH] x86: merge __acpi_map_table Yinghai Lu
2008-07-10 3:17 ` [PATCH] x86: make e820_end return end_of_ram again for 64bit Yinghai Lu
2008-07-10 7:00 ` Ingo Molnar
2008-07-10 11:17 ` [PATCH] x86: e820 remove the range instead of update it to reserved Yinghai Lu
2008-07-11 8:20 ` Ingo Molnar
2008-07-11 3:36 ` [PATCH] x86: save slit Yinghai Lu
2008-07-11 8:22 ` Ingo Molnar
2008-07-11 3:38 ` [PATCH] x86: introduce max_low_pfn_mapped for 64bit Yinghai Lu
2008-07-11 8:26 ` Ingo Molnar
2008-07-11 8:39 ` Yinghai Lu
2008-07-11 8:51 ` Ingo Molnar
2008-07-12 1:41 ` [PATCH] x86: let 32bit use apic_ops too Yinghai Lu
2008-07-12 1:43 ` [PATCH] x86: mach_apicdef.h need to include before smp.h Yinghai Lu
2008-07-12 1:44 ` [PATCH] x86: make read_apic_id return final apicid Yinghai Lu
2008-07-12 8:01 ` [PATCH] x86: make 64bit have get_apic_id Yinghai Lu
2008-07-13 6:28 ` Ingo Molnar
2008-07-13 6:59 ` Ingo Molnar
2008-07-13 7:05 ` Yinghai Lu
2008-07-13 9:23 ` Ingo Molnar
2008-07-13 9:28 ` Ingo Molnar
2008-07-13 16:15 ` Suresh Siddha
2008-07-13 1:19 ` [PATCH] x86: make read_apic_id return final apicid Suresh Siddha
2008-07-13 1:08 ` [PATCH] x86: let 32bit use apic_ops too Suresh Siddha
2008-07-13 2:04 ` Yinghai Lu
2008-07-13 16:28 ` Suresh Siddha
2008-07-13 16:51 ` Maciej W. Rozycki
2008-07-13 17:16 ` Cyrill Gorcunov
2008-07-13 23:46 ` Maciej W. Rozycki
2008-07-14 16:48 ` Cyrill Gorcunov
2008-07-14 17:20 ` Maciej W. Rozycki
2008-07-14 18:09 ` Cyrill Gorcunov
2008-07-14 18:24 ` Maciej W. Rozycki
2008-07-14 18:32 ` Cyrill Gorcunov
2008-07-13 1:43 ` Maciej W. Rozycki
2008-07-13 1:45 ` Yinghai Lu
2008-07-13 1:54 ` Maciej W. Rozycki
2008-07-13 16:43 ` Suresh Siddha
2008-07-13 17:05 ` Maciej W. Rozycki
2008-07-14 5:19 ` [PATCH] x86: let 32bit use apic_ops too - fix Yinghai Lu
2008-07-14 7:12 ` Ingo Molnar
2008-07-14 16:49 ` Suresh Siddha
2008-07-14 17:00 ` Yinghai Lu
2008-07-14 18:03 ` Suresh Siddha
2008-07-18 17:06 ` Ingo Molnar
2008-07-15 17:33 ` Suresh Siddha
2008-07-15 18:10 ` Yinghai Lu
2008-07-15 18:27 ` Suresh Siddha
2008-07-18 17:07 ` Ingo Molnar
2008-07-12 21:30 ` [PATCH] x86: max_low_pfn_mapped fix #1 Yinghai Lu
2008-07-13 9:45 ` Ingo Molnar
2008-07-12 21:31 ` [PATCH] x86: max_low_pfn_mapped fix #2 Yinghai Lu
2008-07-12 21:32 ` [PATCH] x86: max_low_pfn_mapped fix #3 Yinghai Lu
2008-07-13 21:29 ` [PATCH] x86: max_low_pfn_mapped fix #4 Yinghai Lu
2008-07-13 21:30 ` [PATCH] x86: get x86_phys_bits early Yinghai Lu
2008-07-13 21:32 ` [PATCH] x86: make 64bit hpet_set_mapping to use ioremap too Yinghai Lu
2008-07-13 21:50 ` [PATCH] x86: make 64bit hpet_set_mapping to use ioremap too v2 Yinghai Lu
2008-07-10 6:54 ` [PATCH] x86: merge __acpi_map_table Ingo Molnar
2008-07-10 6:53 ` [PATCh] x86: overmapped fix when 4K pages on tail - 64bit Ingo Molnar
2008-07-10 6:57 ` Yinghai Lu
2008-07-10 7:20 ` Ingo Molnar
2008-07-10 7:32 ` Yinghai Lu
2008-07-10 14:16 ` Arjan van de Ven
2008-07-13 14:57 ` Andi Kleen
2008-07-13 15:33 ` Arjan van de Ven
2008-07-13 18:25 ` Andi Kleen
2008-07-13 18:17 ` Yinghai Lu
2008-07-13 18:48 ` Andi Kleen
2008-07-13 19:00 ` Yinghai Lu
2008-07-13 20:32 ` Ingo Molnar
2008-07-13 20:51 ` Andi Kleen
2008-07-14 0:04 ` H. Peter Anvin
2008-07-14 6:39 ` Andi Kleen [this message]
2008-07-09 7:38 ` [PATCH] x86: introduce page_size_mask for 64bit Ingo Molnar
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=487AF4BB.6050805@firstfloor.org \
--to=andi@firstfloor.org \
--cc=arjan@infradead.org \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=suresh.b.siddha@intel.com \
--cc=tglx@linutronix.de \
--cc=yhlu.kernel@gmail.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.