Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1296732

Re: [PATCH 01/11] resource: Add System RAM resource type

Show all headers | View raw

On Wed, Dec 16, 2015 at 02:52:38PM -0700, Toshi Kani wrote:
> This scheme may have a problem, though.  For instance, when someone writes
> a loadable module that searches for "foo", but the "foo" entry may be
> initialized in a distro kernel/driver that cannot be modified.  Since this
> search is only necessary to obtain a range initialized by other module,
> this scenario is likely to happen.  We no longer have ability to search for
> a new entry unless we modify the code that initializes the entry first.

Since when do we pay attention to out-of-tree modules which cannot be
changed?

Regardless, we don't necessarily need to change the callers - we could
add new ones of the form walk_iomem_resource_by_type() or whatever its
name is going to be which uses the ->type attribute of the resource and
phase out the old ones slowly. New code will call the better interfaces,
we should probably even add a checkpatch rule to check for that.

> Even if we avoid strcmp() with @name in the kernel, user applications will
> continue to use @name since that is the only type available in /proc/iomem.
>  For instance, kexec has its own search function with a string name.

See above.

> When a new commonly-used search name comes up, we can define it as a new
> extended I/O resource type similar to IORESOURCE_SYSTEM_RAM.  For the
> current remaining cases, i.e. crash, kexec, and einj, they have no impact
> to performance.  Leaving these special cases aside will keep the ability to
> search for any entry without changing the kernel, and save some memory
> space from adding the new 'type'.

Again, we can leave the old interfaces at peace but going forward, we
should make the searching for resources saner and stop using silly
strings.

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH 01/11] resource: Add System RAM resource type Toshi Kani <toshi.kani@hpe.com> - 2015-12-15 00:40 +0100
  [PATCH 08/11] memremap: Change region_intersects() to use System RAM type Toshi Kani <toshi.kani@hpe.com> - 2015-12-15 00:40 +0100
  [PATCH 06/11] kexec: Set IORESOURCE_SYSTEM_RAM to System RAM Toshi Kani <toshi.kani@hpe.com> - 2015-12-15 00:40 +0100
  [PATCH 10/11] arm/samsung: Change s3c_pm_run_res() to use System RAM type Toshi Kani <toshi.kani@hpe.com> - 2015-12-15 00:40 +0100
    Re: [PATCH 10/11] arm/samsung: Change s3c_pm_run_res() to use System  RAM type Krzysztof Kozlowski <k.kozlowski@samsung.com> - 2015-12-15 01:30 +0100
  [PATCH 07/11] memory-hotplug: Set IORESOURCE_SYSTEM_RAM to System RAM Toshi Kani <toshi.kani@hpe.com> - 2015-12-15 00:40 +0100
  [PATCH 04/11] arch: Set IORESOURCE_SYSTEM_RAM to System RAM Toshi Kani <toshi.kani@hpe.com> - 2015-12-15 00:40 +0100
  [PATCH 09/11] resource: Change walk_system_ram to use System RAM type Toshi Kani <toshi.kani@hpe.com> - 2015-12-15 00:40 +0100
  [PATCH 05/11] xen: Set IORESOURCE_SYSTEM_RAM to System RAM Toshi Kani <toshi.kani@hpe.com> - 2015-12-15 00:50 +0100
  [PATCH 03/11] x86/e820: Set IORESOURCE_SYSTEM_RAM to System RAM Toshi Kani <toshi.kani@hpe.com> - 2015-12-15 00:50 +0100
  Re: [PATCH 01/11] resource: Add System RAM resource type Borislav Petkov <bp@alien8.de> - 2015-12-16 13:30 +0100
    Re: [PATCH 01/11] resource: Add System RAM resource type Toshi Kani <toshi.kani@hpe.com> - 2015-12-16 16:50 +0100
      Re: [PATCH 01/11] resource: Add System RAM resource type Borislav Petkov <bp@alien8.de> - 2015-12-16 16:50 +0100
        Re: [PATCH 01/11] resource: Add System RAM resource type Toshi Kani <toshi.kani@hpe.com> - 2015-12-16 17:40 +0100
          Re: [PATCH 01/11] resource: Add System RAM resource type Borislav Petkov <bp@alien8.de> - 2015-12-16 18:50 +0100
            Re: [PATCH 01/11] resource: Add System RAM resource type Dan Williams <dan.j.williams@intel.com> - 2015-12-16 19:00 +0100
              Re: [PATCH 01/11] resource: Add System RAM resource type Borislav Petkov <bp@alien8.de> - 2015-12-16 19:20 +0100
                Re: [PATCH 01/11] resource: Add System RAM resource type Dan Williams <dan.j.williams@intel.com> - 2015-12-16 20:00 +0100
                Re: [PATCH 01/11] resource: Add System RAM resource type Borislav Petkov <bp@alien8.de> - 2015-12-16 20:20 +0100
                Re: [PATCH 01/11] resource: Add System RAM resource type Toshi Kani <toshi.kani@hpe.com> - 2015-12-16 23:00 +0100
                Re: [PATCH 01/11] resource: Add System RAM resource type Borislav Petkov <bp@alien8.de> - 2015-12-22 12:40 +0100
                Re: [PATCH 01/11] resource: Add System RAM resource type Toshi Kani <toshi.kani@hpe.com> - 2015-12-22 21:10 +0100
                Re: [PATCH 01/11] resource: Add System RAM resource type Borislav Petkov <bp@alien8.de> - 2015-12-23 15:30 +0100
                Re: [PATCH 01/11] resource: Add System RAM resource type Toshi Kani <toshi.kani@hpe.com> - 2015-12-24 03:30 +0100
                Re: [PATCH 01/11] resource: Add System RAM resource type Toshi Kani <toshi.kani@hpe.com> - 2015-12-24 18:10 +0100
                Re: [PATCH 01/11] resource: Add System RAM resource type Borislav Petkov <bp@alien8.de> - 2015-12-24 21:00 +0100
                Re: [PATCH 01/11] resource: Add System RAM resource type Toshi Kani <toshi.kani@hpe.com> - 2015-12-24 22:40 +0100

csiph-web