On 01/20/2015 10:08 AM, Vlastimil Babka wrote: > On 01/20/2015 06:52 AM, Aneesh Kumar K.V wrote: >> Vlastimil Babka <vba...@suse.cz> writes: >> >> is that check correct ? ie, >> >> if ((gfp & GFP_TRANSHUGE) == GFP_TRANSHUGE) >> >> may not always indicate transparent hugepage if defrag = 0 . With defrag >> cleared, we remove __GFP_WAIT from GFP_TRANSHUGE. > > Yep, that looks wrong. Sigh. I guess we can't spare an extra GFP flag to > indicate TRANSHUGE?
I wanted to fix this in __alloc_pages_slowpath(), but actually there's no issue (other than being quite subtle) - if defrag == 0 and thus we don't have __GFP_WAIT, we reach "if (!wait) goto nopage;" and bail out before reaching the checks for GFP_TRANSHUGE. >> static inline gfp_t alloc_hugepage_gfpmask(int defrag, gfp_t extra_gfp) >> { >> return (GFP_TRANSHUGE & ~(defrag ? 0 : __GFP_WAIT)) | extra_gfp; >> } >> >> -aneesh >> >> -- >> To unsubscribe, send a message with 'unsubscribe linux-mm' in >> the body to majord...@kvack.org. For more info on Linux MM, >> see: http://www.linux-mm.org/ . >> Don't email: <a href=mailto:"d...@kvack.org"> em...@kvack.org </a> >> > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majord...@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"d...@kvack.org"> em...@kvack.org </a> > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/