On Tue, 1 May 2007, Nate Diller wrote: > well, leave it to me to reply too quickly, sorry. i think we should > leave simple_prepare_write() the way it is, since it's a library > function itself. the other two callsites in your patch are buffers, > which may themselves be smaller than a page so you would need a > special function for just those two uses, there's no other way to > avoid making two calls to flush_dcache_page(). if it's tremendously > important to you to eliminate open coding of these, maybe make a > 'static int buffer_prepare_write()' or some such in fs/buffer.c
All three sites zap two parts of a page. If we had a zero_user_page2 like this zero_user_page2(page, start1, end1, start2, end2, kmap) then all 3 sites could use the same funtion. libfs.c: zero_user_page_segments(page, 0, from, to, PAGE_CACHE_SIZE, KM_USER0); buffer.c: zero_user_page_segments(page, from, block_start, to, block_end, KM_USER0) zero_user_page_segments(page, blockstart, from, to, block_end, KM_USER0) I did not look through the whole kernel but this zapping segments is likely frequent given the nature of the blocklayer. The 3 call sites pretty ugly on their own. I think it would be good to have one clearly commented version of this somewhere. Call sites will be much clearer since you do not have the kmap_ obfuscation nor the calculation of the length of each segment. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
