All of lore.kernel.org
 help / color / mirror / Atom feed
From: Ira Weiny <ira.weiny@intel.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Dan Williams <dan.j.williams@intel.com>,
	Fenghua Yu <fenghua.yu@intel.com>,
	Rick Edgecombe <rick.p.edgecombe@intel.com>,
	"Shankar, Ravi V" <ravi.v.shankar@intel.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH V10 33/44] kmap: Make kmap work for devmap protected pages
Date: Tue, 17 May 2022 15:46:55 -0700	[thread overview]
Message-ID: <YoQl3yLa4iDCjicO@iweiny-desk3> (raw)
In-Reply-To: <Ynxh/5jewIuGwb5d@iweiny-desk3>

On Wed, May 11, 2022 at 06:25:19PM -0700, Ira wrote:
> On Thu, Apr 28, 2022 at 08:50:34AM -0700, Christoph Hellwig wrote:
> > On Tue, Apr 19, 2022 at 10:06:38AM -0700, ira.weiny@intel.com wrote:
> > > index a77be5630209..32ed07c2994b 100644
> > > --- a/include/linux/highmem-internal.h
> > > +++ b/include/linux/highmem-internal.h
> > > @@ -151,6 +151,8 @@ static inline void totalhigh_pages_add(long count)
> > >  
> > >  #else /* CONFIG_HIGHMEM */
> > >  
> > > +#include <linux/memremap.h>
> > 
> > Uuuh, I'd really prefer to avoid having to pull in memremap.h into
> > basically the whole kernel build.
> > 
> 
> Fair enough.  What should I call a header to store the new pgmap_set_*() calls?
> 
> devmap_prot.h
> 
> ?
> 
> Or I could just add the calls into highmem-internal.h.  That might be more
> appropriate given the new direction of that interface.
> 
> I think I'm leaning toward that vs adding another header.

Ok there is a trade off here which I'm not sure is a good idea.

In order to make kmap faster I carefully placed the devmap_protected() call
completely inline.[1]  This specifically checks the PGMAP_PROTECTION flag in
dev_pagemap.[1]

I see only 2 ways of not including memremap.h in highmem-internal.h.

1) Make this check a function call and place it in memremap.c
2) Move struct dev_pagemap (and it's dependencies) to another header.

Number 2 negates any positive effect of splitting the header file.

Number 1 is going to force some overhead on all ZONE_DEVICE pages if PMEM is in
the system.

Do you think the extra run time overhead is a reasonable trade off to
eliminating the header?

Ira

[1] https://lore.kernel.org/lkml/20220419170649.1022246-29-ira.weiny@intel.com/

  reply	other threads:[~2022-05-17 22:47 UTC|newest]

Thread overview: 61+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-19 17:06 [PATCH V10 00/44] PKS/PMEM: Add Stray Write Protection ira.weiny
2022-04-19 17:06 ` [PATCH V10 01/44] Documentation/protection-keys: Clean up documentation for User Space pkeys ira.weiny
2022-06-07 23:09   ` [tip: x86/mm] " tip-bot2 for Ira Weiny
2022-04-19 17:06 ` [PATCH V10 02/44] x86/pkeys: Clarify PKRU_AD_KEY macro ira.weiny
2022-06-07 23:09   ` [tip: x86/mm] " tip-bot2 for Ira Weiny
2022-04-19 17:06 ` [PATCH V10 03/44] x86/pkeys: Make PKRU macros generic ira.weiny
2022-04-19 17:06 ` [PATCH V10 04/44] x86/fpu: Refactor arch_set_user_pkey_access() ira.weiny
2022-04-19 17:06 ` [PATCH V10 05/44] mm/pkeys: Add Kconfig options for PKS ira.weiny
2022-04-19 17:06 ` [PATCH V10 06/44] x86/pkeys: Add PKS CPU feature bit ira.weiny
2022-04-19 17:06 ` [PATCH V10 07/44] x86/fault: Adjust WARN_ON for pkey fault ira.weiny
2022-04-19 17:06 ` [PATCH V10 08/44] Documentation/pkeys: Add initial PKS documentation ira.weiny
2022-05-09 22:03   ` Kees Cook
2022-05-10 17:18     ` Ira Weiny
2022-05-10 20:17       ` Kees Cook
2022-04-19 17:06 ` [PATCH V10 09/44] mm/pkeys: Provide for PKS key allocation ira.weiny
2022-04-19 17:06 ` [PATCH V10 10/44] x86/pkeys: Enable PKS on cpus which support it ira.weiny
2022-04-19 17:06 ` [PATCH V10 11/44] mm/pkeys: Define PKS page table macros ira.weiny
2022-04-19 17:06 ` [PATCH V10 12/44] x86/pkeys: Introduce pks_write_pkrs() ira.weiny
2022-04-19 17:06 ` [PATCH V10 13/44] x86/pkeys: Preserve the PKS MSR on context switch ira.weiny
2022-04-19 17:06 ` [PATCH V10 14/44] mm/pkeys: Introduce pks_set_readwrite() ira.weiny
2022-05-09 21:38   ` Kees Cook
2022-05-10 21:33     ` Ira Weiny
2022-05-10 22:08       ` Kees Cook
2022-05-10 22:26         ` Edgecombe, Rick P
2022-05-11  3:15           ` Kees Cook
2022-05-11 17:59             ` Ira Weiny
2022-04-19 17:06 ` [PATCH V10 15/44] mm/pkeys: Introduce pks_set_noaccess() ira.weiny
2022-04-19 17:06 ` [PATCH V10 16/44] mm/pkeys: Introduce PKS fault callbacks ira.weiny
2022-04-19 17:06 ` [PATCH V10 17/44] x86/entry: Add auxiliary pt_regs space ira.weiny
2022-04-19 17:06 ` [PATCH V10 18/44] entry: Pass pt_regs to irqentry_exit_cond_resched() ira.weiny
2022-04-19 17:06 ` [PATCH V10 19/44] entry: Add calls for save/restore auxiliary pt_regs ira.weiny
2022-04-19 17:06 ` [PATCH V10 20/44] x86/entry: Define arch_{save|restore}_auxiliary_pt_regs() ira.weiny
2022-04-19 17:06 ` [PATCH V10 21/44] x86/pkeys: Preserve PKRS MSR across exceptions ira.weiny
2022-04-19 17:06 ` [PATCH V10 22/44] x86/fault: Print PKS MSR on fault ira.weiny
2022-04-19 17:06 ` [PATCH V10 23/44] mm/pkeys: Introduce pks_update_exception() ira.weiny
2022-04-19 17:06 ` [PATCH V10 24/44] mm/pkeys: Add pks_available() ira.weiny
2022-04-19 17:06 ` [PATCH V10 25/44] memremap_pages: Add Kconfig for DEVMAP_ACCESS_PROTECTION ira.weiny
2022-04-19 17:06 ` [PATCH V10 26/44] memremap_pages: Introduce pgmap_protection_available() ira.weiny
2022-04-19 17:06 ` [PATCH V10 27/44] memremap_pages: Introduce a PGMAP_PROTECTION flag ira.weiny
2022-04-19 17:06 ` [PATCH V10 28/44] memremap_pages: Introduce devmap_protected() ira.weiny
2022-04-19 17:06 ` [PATCH V10 29/44] memremap_pages: Reserve a PKS pkey for eventual use by PMEM ira.weiny
2022-04-19 17:06 ` [PATCH V10 30/44] memremap_pages: Set PKS pkey in PTEs if requested ira.weiny
2022-04-19 17:06 ` [PATCH V10 31/44] memremap_pages: Define pgmap_set_{readwrite|noaccess}() calls ira.weiny
2022-04-19 17:06 ` [PATCH V10 32/44] memremap_pages: Add memremap.pks_fault_mode ira.weiny
2022-04-19 17:06 ` [PATCH V10 33/44] kmap: Make kmap work for devmap protected pages ira.weiny
2022-04-28 15:50   ` Christoph Hellwig
2022-05-12  1:25     ` Ira Weiny
2022-05-17 22:46       ` Ira Weiny [this message]
2022-05-18  7:33         ` Christoph Hellwig
2022-05-19 20:29           ` Ira Weiny
2022-04-19 17:06 ` [PATCH V10 34/44] dax: Stray access protection for dax_direct_access() ira.weiny
2022-04-19 17:06 ` [PATCH V10 35/44] nvdimm/pmem: Enable stray access protection ira.weiny
2022-04-19 17:06 ` [PATCH V10 36/44] devdax: " ira.weiny
2022-04-19 17:06 ` [PATCH V10 37/44] mm/pkeys: PKS testing, add initial test code ira.weiny
2022-04-19 17:06 ` [PATCH V10 38/44] x86/selftests: Add test_pks ira.weiny
2022-04-19 17:06 ` [PATCH V10 39/44] mm/pkeys: PKS testing, add a fault call back ira.weiny
2022-04-19 17:06 ` [PATCH V10 40/44] mm/pkeys: PKS testing, add pks_set_*() tests ira.weiny
2022-04-19 17:06 ` [PATCH V10 41/44] mm/pkeys: PKS testing, test context switching ira.weiny
2022-04-19 17:06 ` [PATCH V10 42/44] mm/pkeys: PKS testing, Add exception test ira.weiny
2022-04-19 17:06 ` [PATCH V10 43/44] mm/pkeys: PKS testing, test pks_update_exception() ira.weiny
2022-04-19 17:06 ` [PATCH V10 44/44] mm/pkeys: PKS testing, add test for all keys ira.weiny

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=YoQl3yLa4iDCjicO@iweiny-desk3 \
    --to=ira.weiny@intel.com \
    --cc=dan.j.williams@intel.com \
    --cc=dave.hansen@linux.intel.com \
    --cc=fenghua.yu@intel.com \
    --cc=hch@infradead.org \
    --cc=hpa@zytor.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=ravi.v.shankar@intel.com \
    --cc=rick.p.edgecombe@intel.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.