From: Al Viro <viro@zeniv.linux.org.uk>
To: "Maciej W. Rozycki" <macro@orcam.me.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
alpha <linux-alpha@vger.kernel.org>
Subject: Re: [PATCH 7/7] alpha: lazy FPU switching
Date: Sat, 30 Oct 2021 22:13:08 +0000 [thread overview]
Message-ID: <YX3DdBbNkTeUoGit@zeniv-ca.linux.org.uk> (raw)
In-Reply-To: <alpine.DEB.2.21.2110302215080.61663@angie.orcam.me.uk>
On Sat, Oct 30, 2021 at 10:25:34PM +0100, Maciej W. Rozycki wrote:
> On Sat, 30 Oct 2021, Al Viro wrote:
>
> > 1) lazy FPU part has a braino in it; __save_fpu() in alpha_fork() et.al. should
> > be called *after* do_switch_stack(), not before it. Another (minor) problem is
> > that use of jsr for calls for functions in the same object file is stupid -
> > should be bsr instead. Not a bug, per se, but it's clearly suboptimal. Both
> > fixes folded.
>
> The linker is supposed to relax any eligible JSR to BSR (same with JMP vs
> BR) so it shouldn't really matter, and writing it down as JSR is surely
> more flexible as you don't have to track which caller/callee is where.
All within arch/alpha/kernel/entry.S. If that ever grows past 1M insns, we
have much worse problems... Other callers are from C, so they all end up
with jsr, obviously.
next prev parent reply other threads:[~2021-10-30 22:13 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-25 2:54 [PATCHES] alpha asm glue cleanups and fixes Al Viro
2021-09-25 2:55 ` [PATCH 1/6] alpha: fix TIF_NOTIFY_SIGNAL handling Al Viro
2021-09-25 2:55 ` [PATCH 2/6] alpha: _TIF_ALLWORK_MASK is unused Al Viro
2021-09-25 2:55 ` [PATCH 3/6] alpha: fix syscall entry in !AUDUT_SYSCALL case Al Viro
2021-09-25 2:55 ` [PATCH 4/6] alpha: fix handling of a3 on straced syscalls Al Viro
2021-09-25 2:55 ` [PATCH 5/6] alpha: syscall exit cleanup Al Viro
2021-09-25 2:55 ` [PATCH 6/6] alpha: ret_from_fork can go straight to ret_to_user Al Viro
2021-09-25 2:55 ` [PATCH 7/7] alpha: lazy FPU switching Al Viro
2021-09-25 19:07 ` Linus Torvalds
2021-09-25 20:43 ` Al Viro
2021-09-25 23:18 ` Linus Torvalds
2021-09-26 0:31 ` Al Viro
2021-10-30 20:46 ` Al Viro
2021-10-30 20:46 ` Al Viro
2021-10-30 21:25 ` Maciej W. Rozycki
2021-10-30 22:13 ` Al Viro [this message]
2021-09-26 9:08 ` John Paul Adrian Glaubitz
2021-09-25 2:59 ` [PATCHES] alpha asm glue cleanups and fixes Al Viro
2022-09-02 1:48 ` Al Viro
2022-09-02 1:50 ` [PATCH v2 1/7] alpha: fix TIF_NOTIFY_SIGNAL handling Al Viro
2022-09-02 1:50 ` [PATCH v2 2/7] alpha: _TIF_ALLWORK_MASK is unused Al Viro
2022-09-02 1:50 ` [PATCH v2 3/7] alpha: fix syscall entry in !AUDUT_SYSCALL case Al Viro
2022-09-02 1:50 ` [PATCH v2 4/7] alpha: fix handling of a3 on straced syscalls Al Viro
2022-09-02 1:50 ` [PATCH v2 5/7] alpha: syscall exit cleanup Al Viro
2022-09-02 1:50 ` [PATCH v2 6/7] alpha: ret_from_fork can go straight to ret_to_user Al Viro
2022-09-02 1:50 ` [PATCH v2 7/7] alpha: lazy FPU switching Al Viro
2022-09-02 4:24 ` Linus Torvalds
2022-09-02 5:07 ` Al Viro
2022-09-02 5:14 ` Al Viro
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