On Wed, Sep 26, 2018 at 11:24:55AM -0700, Bart Van Assche wrote: > On Wed, 2018-09-26 at 17:06 +0200, Johannes Thumshirn wrote: > > On Wed, Sep 26, 2018 at 04:57:32PM +0200, Christoph Hellwig wrote: > > > I don't think this actually works given that rpm_status only exists > > > if CONFIG_PM is set. > > > > I think it'll work as GCC does constant propagation. There are > > actually some places in the kernel that follow this pattern. > > This is what gcc on my development system thinks about that proposal: > > In file included from ./arch/x86/include/asm/bug.h:83:0, > from ./include/linux/bug.h:5, > from ./include/linux/thread_info.h:12, > from ./arch/x86/include/asm/preempt.h:7, > from ./include/linux/preempt.h:81, > from ./include/linux/spinlock.h:51, > from ./include/linux/seqlock.h:36, > from ./include/linux/time.h:6, > from ./include/linux/stat.h:19, > from ./include/linux/module.h:10, > from block/blk-core.c:15: > block/blk-core.c: In function ‘elv_next_request’: > block/blk-core.c:2795:44: error: ‘struct request_queue’ has no member named ‘rpm_status’; did you mean ‘stats’? > WARN_ON_ONCE(q->rpm_status == RPM_SUSPENDED); > ^ > ./include/asm-generic/bug.h:69:25: note: in definition of macro ‘WARN_ON_ONCE’ > int __ret_warn_on = !!(condition); \ > ^~~~~~~~~ > scripts/Makefile.build:305: recipe for target 'block/blk-core.o' failed Aparently this only works for functions and not struct members, my bad. Johannes -- Johannes Thumshirn Storage jthumshirn@xxxxxxx +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850
