On Thu, May 25, 2017 at 02:46:28PM +0800, Huang, Ying wrote: > From: Huang Ying <ying.huang@xxxxxxxxx> > > In this patch, BIO_MAX_PAGES is changed from 256 to HPAGE_PMD_NR if > CONFIG_THP_SWAP is enabled and HPAGE_PMD_NR > 256. This is to support > THP (Transparent Huge Page) swap optimization. Where the THP will be > write to disk as a whole instead of HPAGE_PMD_NR normal pages to batch > the various operations during swap. And the page is likely to be > written to disk to free memory when system memory goes really low, the > memory pool need to be used to avoid deadlock. > > Signed-off-by: "Huang, Ying" <ying.huang@xxxxxxxxx> > Cc: Johannes Weiner <hannes@xxxxxxxxxxx> > Cc: Minchan Kim <minchan@xxxxxxxxxx> > Cc: Jens Axboe <axboe@xxxxxxxxx> > Cc: Ming Lei <tom.leiming@xxxxxxxxx> > Cc: Shaohua Li <shli@xxxxxx> > Cc: linux-block@xxxxxxxxxxxxxxx > --- > include/linux/bio.h | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/include/linux/bio.h b/include/linux/bio.h > index d1b04b0e99cf..314796486507 100644 > --- a/include/linux/bio.h > +++ b/include/linux/bio.h > @@ -38,7 +38,15 @@ > #define BIO_BUG_ON > #endif > > +#ifdef CONFIG_THP_SWAP > +#if HPAGE_PMD_NR > 256 > +#define BIO_MAX_PAGES HPAGE_PMD_NR > +#else > #define BIO_MAX_PAGES 256 > +#endif > +#else > +#define BIO_MAX_PAGES 256 > +#endif > > #define bio_prio(bio) (bio)->bi_ioprio > #define bio_set_prio(bio, prio) ((bio)->bi_ioprio = prio) Last time we discussed we should use multipage bvec for this usage. I will rebase the last post on v4.12-rc and kick if off again since the raid cleanup is just done on v4.11. http://marc.info/?t=148453679000002&r=1&w=2 Thanks, Ming -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
