Linux SNPS ARC Archive on lore.kernel.org
 help / color / Atom feed
From: Joseph Myers <joseph@codesourcery.com>
To: Alistair Francis <alistair23@gmail.com>
Cc: Florian Weimer <fweimer@redhat.com>,
	GNU C Library <libc-alpha@sourceware.org>,
	Arnd Bergmann <arnd@arndb.de>, Vineet Gupta <vineetg76@gmail.com>,
	Palmer Dabbelt <palmerdabbelt@google.com>,
	Zong Li <zongbox@gmail.com>,
	Alistair Francis <alistair.francis@wdc.com>,
	Adhemerval Zanella <adhemerval.zanella@linaro.org>,
	"Maciej W. Rozycki" <macro@wdc.com>,
	arcml <linux-snps-arc@lists.infradead.org>
Subject: Re: [RFC v6 07/23] RISC-V: Use 64-bit time_t and off_t for RV32 and RV64
Date: Wed, 12 Feb 2020 01:30:46 +0000
Message-ID: <alpine.DEB.2.21.2002120123230.3988@digraph.polyomino.org.uk> (raw)
In-Reply-To: <CAKmqyKMyf2psPp+-EHoidvbPbSXv0=dP26GjVQnT5BUriLc1gA@mail.gmail.com>

On Tue, 11 Feb 2020, Alistair Francis wrote:

> > > diff --git a/sysdeps/unix/sysv/linux/riscv/bits/typesizes.h b/sysdeps/unix/sysv/linux/riscv/bits/typesizes.h
> > > new file mode 100644
> > > index 0000000000..0da3bdeb5d
> > > --- /dev/null
> > > +++ b/sysdeps/unix/sysv/linux/riscv/bits/typesizes.h
> >
> > I was hoping newer arches could simply use the asm-generic one ?
> 
> We need to specify that RV32 uses a 64-bit time_t. The generic ones
> don't do that for 32-bit arches.

Since it seems we'd like future 32-bit ports of glibc to use 64-bit time 
and offsets, we should make that as easy as possible.

That is, you need an RISC-V-specific bits/timesize.h.  But you shouldn't 
need an RISC-V-specific bits/typesizes.h - rather, make the linux/generic 
one do the right thing for __TIME_T_TYPE based on bits/timesize.h.  And 
have some other header that 32-bit linux/generic ports can use to say 
whether they use the 64-bit offset/stat/statfs interface, that 
bits/typesizes.h can use together with its existing __LP64__ check, and 
make the definitions of __OFF_T_TYPE etc. check that as well, and then you 
shouldn't need an RISC-V-specific bits/typesizes.h - the RISC-V-specific 
headers should be strictly minimal.  (No architecture-specific 
bits/time64.h headers should be needed in any case.)

At some point (or indeed now) we might flip the default for linux/generic 
so the architectures needing an architecture-specific header are only the 
older 32-bit linux/generic architectures that have support for 32-bit 
times and offsets, and the newer ones with no such support don't need such 
a header.

-- 
Joseph S. Myers
joseph@codesourcery.com

_______________________________________________
linux-snps-arc mailing list
linux-snps-arc@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-snps-arc

  reply index

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <cover.1578824547.git.alistair.francis@wdc.com>
     [not found] ` <4e95f95966d8d7c6a8339160dc62d81c1f6a1bfb.1578824547.git.alistair.francis@wdc.com>
2020-02-12  0:14   ` Vineet Gupta
2020-02-12  0:14     ` Alistair Francis
2020-02-12  1:30       ` Joseph Myers [this message]
2020-02-14 22:39         ` Alistair Francis
2020-02-18 23:05           ` switching ARC to 64-bit time_t (Re: [RFC v6 07/23] RISC-V: Use 64-bit time_t and off_t for RV32 and RV64) Vineet Gupta
2020-02-18 23:13             ` Joseph Myers
2020-02-12  1:42       ` [RFC v6 07/23] RISC-V: Use 64-bit time_t and off_t for RV32 and RV64 Vineet Gupta
2020-02-12 12:58         ` Arnd Bergmann
2020-02-19  0:56   ` Vineet Gupta
2020-02-19  1:03     ` Alistair Francis
2020-02-19  1:31       ` Vineet Gupta

Reply instructions:

You may reply publically 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=alpine.DEB.2.21.2002120123230.3988@digraph.polyomino.org.uk \
    --to=joseph@codesourcery.com \
    --cc=adhemerval.zanella@linaro.org \
    --cc=alistair.francis@wdc.com \
    --cc=alistair23@gmail.com \
    --cc=arnd@arndb.de \
    --cc=fweimer@redhat.com \
    --cc=libc-alpha@sourceware.org \
    --cc=linux-snps-arc@lists.infradead.org \
    --cc=macro@wdc.com \
    --cc=palmerdabbelt@google.com \
    --cc=vineetg76@gmail.com \
    --cc=zongbox@gmail.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

Linux SNPS ARC Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-snps-arc/0 linux-snps-arc/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-snps-arc linux-snps-arc/ https://lore.kernel.org/linux-snps-arc \
		linux-snps-arc@lists.infradead.org
	public-inbox-index linux-snps-arc

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.infradead.lists.linux-snps-arc


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git