From mboxrd@z Thu Jan 1 00:00:00 1970 Message-Id: <200006290602.IAA01677@piglet.grunz.lu> Date: Thu, 29 Jun 2000 08:02:17 +0200 (CEST) From: Michel Lanners Reply-To: mlan@cpu.lu Subject: Re: ide_delay_50ms() freezing on PPC? To: bh40@calva.net cc: linuxppc-dev@lists.linuxppc.org, andre@linux-ide.org In-Reply-To: <20000627083003.23370@mailhost.mipsys.com> MIME-Version: 1.0 Content-Type: TEXT/plain; charset=us-ascii Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: Hi all, On 27 Jun, this message from Benjamin Herrenschmidt echoed through cyberspace: > Can you check the generated code for the loop ? Does it actually re-dead > jiffies from memory or not ? (Did the compiler wrongly tried to optimise > it ?). Here is the code as it appears in vmlinux: c00ba91c : c00ba91c: 3d 20 c0 21 lis r9,-16351 c00ba920: 81 69 c1 ec lwz r11,-15892(r9) c00ba924: 39 6b 00 06 addi r11,r11,6 c00ba928: 80 09 c1 ec lwz r0,-15892(r9) c00ba92c: 7d 40 58 51 subf. r10,r0,r11 c00ba930: 41 81 ff f8 bgt c00ba928 c00ba934: 4e 80 00 20 blr I suppose r9 points to a symbol table somewhere, and the lwz loads a specific symbol in there, which in this case should be the value of jiffies. AFAICS, the jiffies value is thus correctly reloaded at c00ba928. Looks OK to me, no? Michel ------------------------------------------------------------------------- Michel Lanners | " Read Philosophy. Study Art. 23, Rue Paul Henkes | Ask Questions. Make Mistakes. L-1710 Luxembourg | email mlan@cpu.lu | http://www.cpu.lu/~mlan | Learn Always. " ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/