From: Yves-Alexis Perez <corsac@debian.org>
To: Yang Shi <shy828301@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>,
jirislaby@kernel.org, surenb@google.com, riel@surriel.com,
cl@linux.com, akpm@linux-foundation.org,
yang@os.amperecomputing.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org,
Salvatore Bonaccorso <carnil@debian.org>,
Ben Hutchings <ben@decadent.org.uk>
Subject: Re: [PATCH] mm: huge_memory: don't force huge page alignment on 32 bit
Date: Fri, 12 Jul 2024 16:41:59 +0200 [thread overview]
Message-ID: <ZpFAt6ha2KbFRoFn@corsac.net> (raw)
In-Reply-To: <CAHbLzkpitWRK2q3JidRdyQxajz+MixiO1bX08btVu9Ch0i6Kxw@mail.gmail.com>
On Thu, Jul 11, 2024 at 01:53:04PM -0700, Yang Shi wrote:
> On Thu, Jul 11, 2024 at 1:50 PM Matthew Wilcox <willy@infradead.org> wrote:
> >
> > On Thu, Jul 11, 2024 at 01:47:00PM -0700, Yang Shi wrote:
> > > +++ b/mm/huge_memory.c
> > > @@ -857,7 +857,8 @@ static unsigned long
> > > __thp_get_unmapped_area(struct file *filp,
> > > loff_t off_align = round_up(off, size);
> > > unsigned long len_pad, ret, off_sub;
> > >
> > > - if (IS_ENABLED(CONFIG_32BIT) || in_compat_syscall())
> > > + if (IS_ENABLED(CONFIG_32BIT) || IS_ENABLED(CONFIG_X86_32) ||
> > > + in_compat_syscall())
> >
> > Why not:
> >
> > if (!IS_ENABLED(CONFIG_64BIT) || in_compat_syscall())
>
> Nothing specific, just didn't think of it, sigh...
>
> Thanks for the suggestion. Definitely preferable way.
>
And I just did a quick test rebuilding a kernel with
!IS_ENABLED(CONFIG_64BIT) and running on an i386 Debian sid
installation.
I can confirm it seems to work as intended:
Before:
root@testvm:~# uname -a
Linux testvm 6.9.8-686-pae #1 SMP PREEMPT_DYNAMIC Debian 6.9.8-1 (2024-07-07) i686 GNU/Linux
root@testvm:~# for i in {0..9}; do cat /proc/self/maps |grep libc.so |head -n1; done
b7c00000-b7c22000 r--p 00000000 fe:00 933 /usr/lib/i386-linux-gnu/libc.so.6
b7c00000-b7c22000 r--p 00000000 fe:00 933 /usr/lib/i386-linux-gnu/libc.so.6
b7c00000-b7c22000 r--p 00000000 fe:00 933 /usr/lib/i386-linux-gnu/libc.so.6
b7c00000-b7c22000 r--p 00000000 fe:00 933 /usr/lib/i386-linux-gnu/libc.so.6
b7c00000-b7c22000 r--p 00000000 fe:00 933 /usr/lib/i386-linux-gnu/libc.so.6
b7c00000-b7c22000 r--p 00000000 fe:00 933 /usr/lib/i386-linux-gnu/libc.so.6
b7c00000-b7c22000 r--p 00000000 fe:00 933 /usr/lib/i386-linux-gnu/libc.so.6
b7c00000-b7c22000 r--p 00000000 fe:00 933 /usr/lib/i386-linux-gnu/libc.so.6
b7c00000-b7c22000 r--p 00000000 fe:00 933 /usr/lib/i386-linux-gnu/libc.so.6
b7c00000-b7c22000 r--p 00000000 fe:00 933 /usr/lib/i386-linux-gnu/libc.so.6
After:
root@testvm:~# uname -a
Linux testvm 6.9.8+ #1 SMP PREEMPT_DYNAMIC Fri Jul 12 15:23:07 CEST 2024 i686 GNU/Linux
root@testvm:~# for i in {0..9}; do cat /proc/self/maps |grep libc.so |head -n1; done
b7cf3000-b7d15000 r--p 00000000 fe:00 933 /usr/lib/i386-linux-gnu/libc.so.6
b7d7a000-b7d9c000 r--p 00000000 fe:00 933 /usr/lib/i386-linux-gnu/libc.so.6
b7d8b000-b7dad000 r--p 00000000 fe:00 933 /usr/lib/i386-linux-gnu/libc.so.6
b7d4b000-b7d6d000 r--p 00000000 fe:00 933 /usr/lib/i386-linux-gnu/libc.so.6
b7d64000-b7d86000 r--p 00000000 fe:00 933 /usr/lib/i386-linux-gnu/libc.so.6
b7d15000-b7d37000 r--p 00000000 fe:00 933 /usr/lib/i386-linux-gnu/libc.so.6
b7c9e000-b7cc0000 r--p 00000000 fe:00 933 /usr/lib/i386-linux-gnu/libc.so.6
b7d68000-b7d8a000 r--p 00000000 fe:00 933 /usr/lib/i386-linux-gnu/libc.so.6
b7cf6000-b7d18000 r--p 00000000 fe:00 933 /usr/lib/i386-linux-gnu/libc.so.6
b7ce6000-b7d08000 r--p 00000000 fe:00 933 /usr/lib/i386-linux-gnu/libc.so.6
So:
Tested-By: Yves-Alexis Perez <corsac@debian.org>
I didn't try on other 32b architectures though.
Regards,
--
Yves-Alexis Perez
next prev parent reply other threads:[~2024-07-12 14:43 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-18 13:35 Yang Shi
2024-01-18 18:05 ` Yang Shi
2024-01-19 0:16 ` Matthew Wilcox
2024-01-18 20:14 ` Matthew Wilcox
2024-01-18 20:39 ` Yang Shi
2024-01-19 17:16 ` Rik van Riel
2024-01-25 8:53 ` Michal Hocko
2024-01-26 9:36 ` Jiri Slaby
2024-01-26 9:41 ` Jiri Slaby
2024-01-26 10:51 ` Michal Hocko
2024-02-03 9:24 ` Thorsten Leemhuis
2024-02-05 17:07 ` Yang Shi
2024-02-05 17:53 ` Linux regression tracking (Thorsten Leemhuis)
2024-02-12 13:45 ` Thorsten Leemhuis
2024-02-18 9:26 ` Greg KH
2024-07-11 20:10 ` Yves-Alexis Perez
2024-07-11 20:47 ` Yang Shi
2024-07-11 20:50 ` Matthew Wilcox
2024-07-11 20:53 ` Yang Shi
2024-07-12 14:41 ` Yves-Alexis Perez [this message]
2024-07-12 15:31 ` Yang Shi
2024-07-11 20:52 ` Ben Hutchings
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