Ming Lei <ming.lei@xxxxxxxxxx> writes: > 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 for your information! I will rebase my patchset on that after they are merged. From now on, this patch and the next one [07/13] is only a temporary workaround for testing. Best Regards, Huang, Ying > 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>
