This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
Re: glibc 2.21 - Machine maintainers, please test your machines.
- From: "H.J. Lu" <hjl dot tools at gmail dot com>
- To: Chris Metcalf <cmetcalf at ezchip dot com>
- Cc: Torvald Riegel <triegel at redhat dot com>, "Carlos O'Donell" <carlos at redhat dot com>, GNU C Library <libc-alpha at sourceware dot org>, David Miller <davem at davemloft dot net>, Richard Henderson <rth at redhat dot com>, Mike Frysinger <vapier at gentoo dot org>, Andreas Schwab <schwab at suse dot de>, "Joseph S. Myers" <joseph at codesourcery dot com>, Kaz Kojima <kkojima at rr dot iij4u dot or dot jp>, Thomas Schwinge <thomas at codesourcery dot com>, Marcus Shawcroft <marcus dot shawcroft at linaro dot org>, Chung-Lin Tang <chunglin_tang at mentor dot com>, Adhemerval Zanella <azanella at linux dot vnet dot ibm dot com>, Andreas Krebbel <krebbel at linux dot vnet dot ibm dot com>
- Date: Sun, 25 Jan 2015 15:05:02 -0800
- Subject: Re: glibc 2.21 - Machine maintainers, please test your machines.
- Authentication-results: sourceware.org; auth=none
- References: <54C2BDD7 dot 7000304 at redhat dot com> <54C3B6D5 dot 3090308 at ezchip dot com> <1422119595 dot 29655 dot 42 dot camel at triegel dot csb> <54C5094A dot 8060300 at ezchip dot com> <54C51D94 dot 6030007 at ezchip dot com> <CAMe9rOpOuuC_Bf1eHs9iaiUY6V-fVMHUCKZPAwje_NemBy84wA at mail dot gmail dot com> <20150125215150 dot GA15033 at gmail dot com> <54C569E5 dot 9050305 at ezchip dot com>
On Sun, Jan 25, 2015 at 2:10 PM, Chris Metcalf <cmetcalf@ezchip.com> wrote:
> On 1/25/2015 4:51 PM, H.J. Lu wrote:
>
>> This is for x86. Each target can do something like it if needed.
>
>
> This does change the ABI for existing code, however, which may legitimately
> have sem_t objects that are only aligned to 4-byte boundaries. Your change
> is a good idea for new platforms. I suppose we could also do something
> with symbol versioning to use it for existing 32-bit platforms with
> 64-bit atomics, too. So there seem to be multiple fixes we can consider.
>
It doesn't change the size, only increases alignment from 4 bytes to 8 bytes.
It may not work on all targets. It works for x32.
--
H.J.