On 2022/4/15 4:43, Andrew Morton wrote: > On Thu, 14 Apr 2022 20:02:02 +0800 Miaohe Lin <linmiaohe@xxxxxxxxxx> wrote: > >> Since commit 6d6435811c19 ("remove bdi_congested() and wb_congested() and >> related functions"), there is no congested backing device check anymore. >> Correct the comment accordingly. >> >> ... >> >> --- a/mm/vmscan.c >> +++ b/mm/vmscan.c >> @@ -2334,8 +2334,7 @@ static unsigned int move_pages_to_lru(struct lruvec *lruvec, >> /* >> * If a kernel thread (such as nfsd for loop-back mounts) services >> * a backing device by writing to the page cache it sets PF_LOCAL_THROTTLE. >> - * In that case we should only throttle if the backing device it is >> - * writing to is congested. In other cases it is safe to throttle. >> + * In that case we should not throttle it otherwise it is safe to do so. >> */ >> static int current_may_throttle(void) >> { > > That's a bit awkward to read. I tweaked it, and reflowed the comment > to 80 cols. > > --- a/mm/vmscan.c~mm-vmscan-fix-comment-for-current_may_throttle-fix > +++ a/mm/vmscan.c > @@ -2332,9 +2332,9 @@ static unsigned int move_pages_to_lru(st > } > > /* > - * If a kernel thread (such as nfsd for loop-back mounts) services > - * a backing device by writing to the page cache it sets PF_LOCAL_THROTTLE. > - * In that case we should not throttle it otherwise it is safe to do so. > + * If a kernel thread (such as nfsd for loop-back mounts) services a backing > + * device by writing to the page cache it sets PF_LOCAL_THROTTLE. In this case > + * we should not throttle. Otherwise it is safe to do so. > */ > static int current_may_throttle(void) > { > _ Looks better. Many thanks for doing this! :) > > . >