Sounds good.
Reviewed-by: William Kucharski
> On Apr 6, 2021, at 11:48 AM, Collin Fijalkovich
> wrote:
>
> Instrumenting filemap_nr_thps_inc() should be sufficient for ensuring
> writable file mappings will not be THP-backed.
>
> If filemap_nr_thps_dec() in unaccount_page_cache_page() and
>
Instrumenting filemap_nr_thps_inc() should be sufficient for ensuring
writable file mappings will not be THP-backed.
If filemap_nr_thps_dec() in unaccount_page_cache_page() and
filemap_nr_thps() in do_dentry_open() race, the worst case is an
unnecessary truncation. We could introduce a memory barr
I saw a similar change a few years ago with my prototype:
https://lore.kernel.org/linux-mm/5bb682e1-dd52-4aa9-83e9-def091e0c...@oracle.com/
the key being a very nice drop in iTLB-load-misses, so it looks like your code
is
having the right effect.
What about the call to filemap_nr_thps_dec() i
v2 has been uploaded with performance testing results:
https://lore.kernel.org/patchwork/patch/1408266/
On Mon, Mar 22, 2021 at 2:59 PM Collin Fijalkovich
wrote:
>
> Transparent huge pages are supported for read-only non-shmem filesystems,
> but are only used for vmas with VM_DENYWRITE. This co
There will be an immediate performance hit when the file is opened for
write, as its associated pages are removed from the page cache. While
the writer is present there will be the usual overhead of using 4kB
pages instead of THPs, but there should not be an additional penalty.
It is problematic if
> On Mar 23, 2021, at 10:13 AM, Collin Fijalkovich
> wrote:
>
> Question: when we use this on shared library, the library is still
> writable. When the
> shared library is opened for write, these pages will refault in as 4kB
> pages, right?
>
> That's correct, while a file is opened for wri
I like this, it reminds me of the changes I proposed a few years ago to try
to automatically map read-only text regions of appropriate sizes and
alignment with THPs.
My concern had always been whether commercial software and distro vendors
would buy into supplying the appropriate linker flags when
On Mon, Mar 22, 2021 at 3:00 PM Collin Fijalkovich
wrote:
>
> Transparent huge pages are supported for read-only non-shmem filesystems,
> but are only used for vmas with VM_DENYWRITE. This condition ensures that
> file THPs are protected from writes while an application is running
> (ETXTBSY). An
Transparent huge pages are supported for read-only non-shmem filesystems,
but are only used for vmas with VM_DENYWRITE. This condition ensures that
file THPs are protected from writes while an application is running
(ETXTBSY). Any existing file THPs are then dropped from the page cache
when a file
9 matches
Mail list logo
