Messages in this thread | | | Date | Wed, 25 Sep 2013 14:17:02 -0700 | From | Zach Brown <> | Subject | Re: [PATCH 1/6] block: Introduce bio_for_each_page() |
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> void zero_fill_bio(struct bio *bio) > { > - unsigned long flags; > struct bio_vec bv; > struct bvec_iter iter; > > - bio_for_each_segment(bv, bio, iter) { > +#if defined(CONFIG_HIGHMEM) || defined(ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE) > + bio_for_each_page(bv, bio, iter) { > + unsigned long flags; > char *data = bvec_kmap_irq(&bv, &flags); > memset(data, 0, bv.bv_len); > flush_dcache_page(bv.bv_page); > bvec_kunmap_irq(data, &flags); > } > +#else > + bio_for_each_segment(bv, bio, iter) > + memset(page_address(bv.bv_page) + bv.bv_offset, > + 0, bv.bv_len); > +#endif
This looks pretty sketchy. I'd expect this to be doable with one loop and that bvec_kmap_irq() and flush_dcache_page() would fall back to page_address() and nops when they're not needed.
Where did this come from?
- z
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