Trond Myklebust <[email protected]> wrote: > > > @@ -432,7 +432,12 @@ static int nfs_release_page(struct page *page, gfp_t > > > gfp) > > > /* If PagePrivate() is set, then the page is not freeable */ > > > if (PagePrivate(page)) > > > return 0; > > > - return nfs_fscache_release_page(page, gfp); > > > + if (PageFsCache(page)) { > > > + if (!(gfp & __GFP_DIRECT_RECLAIM) || !(gfp & __GFP_FS)) > > > + return false; > > > + wait_on_page_fscache(page); > > > + } > > > + return true; > > > } > > I've found this generally not to be safe. The VM calls ->release_page() > from a variety of contexts, and often fails to report it correctly in > the gfp flags. That's particularly true of the stuff in mm/vmscan.c. > This is why we have the check above that vetos page removal upon > PagePrivate() being set.
[Adding Willy and the mm crew to the cc list] I wonder if that matters in this case. In the worst case, we'll wait for the page to cease being DMA'd - but we won't return true if it is. But if vmscan is generating the wrong VM flags, we should look at fixing that. David -- Linux-cachefs mailing list [email protected] https://listman.redhat.com/mailman/listinfo/linux-cachefs
