| Message ID | 20210906052926.6007-1-jaewon31.kim@samsung.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | zram_drv: allow reclaim on bio_alloc | expand |
On Mon, Sep 06, 2021 at 02:29:26PM +0900, Jaewon Kim wrote: > The read_from_bdev_async is not called on atomic context. So GFP_NOIO is > available rather than GFP_ATOMIC. If there were reclaimable pages with > GFP_NOIO, we can avoid allocation failure and page fault failure. > > Reported-by: Yong-Taek Lee <ytk.lee@samsung.com> > Signed-off-by: Jaewon Kim <jaewon31.kim@samsung.com> > --- > drivers/block/zram/zram_drv.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c > index fcaf2750f68f..53be528a39a2 100644 > --- a/drivers/block/zram/zram_drv.c > +++ b/drivers/block/zram/zram_drv.c > @@ -587,7 +587,7 @@ static int read_from_bdev_async(struct zram *zram, struct bio_vec *bvec, > { > struct bio *bio; > > - bio = bio_alloc(GFP_ATOMIC, 1); > + bio = bio_alloc(GFP_NOIO|__GFP_HIGHMEM, 1); Passing __GFP_HIGHMEM to bio_alloc does not make any sense whatsoever.
> > >--------- Original Message --------- >Sender : Christoph Hellwig <hch@infradead.org> >Date : 2021-09-06 17:39 (GMT+9) >Title : Re: [PATCH] zram_drv: allow reclaim on bio_alloc > >On Mon, Sep 06, 2021 at 02:29:26PM +0900, Jaewon Kim wrote: >> The read_from_bdev_async is not called on atomic context. So GFP_NOIO is >> available rather than GFP_ATOMIC. If there were reclaimable pages with >> GFP_NOIO, we can avoid allocation failure and page fault failure. >> >> Reported-by: Yong-Taek Lee <ytk.lee@samsung.com> >> Signed-off-by: Jaewon Kim <jaewon31.kim@samsung.com> >> --- >> drivers/block/zram/zram_drv.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c >> index fcaf2750f68f..53be528a39a2 100644 >> --- a/drivers/block/zram/zram_drv.c >> +++ b/drivers/block/zram/zram_drv.c >> @@ -587,7 +587,7 @@ static int read_from_bdev_async(struct zram *zram, struct bio_vec *bvec, >> { >> struct bio *bio; >> >> - bio = bio_alloc(GFP_ATOMIC, 1); >> + bio = bio_alloc(GFP_NOIO|__GFP_HIGHMEM, 1); > >Passing __GFP_HIGHMEM to bio_alloc does not make any sense whatsoever. > Correct, let me remove __GFP_HIGHMEM if I send v2 patch. Thank you
Hi Jaewon, On Mon, Sep 06, 2021 at 06:14:48PM +0900, Jaewon Kim wrote: > > > > > >--------- Original Message --------- > >Sender : Christoph Hellwig <hch@infradead.org> > >Date : 2021-09-06 17:39 (GMT+9) > >Title : Re: [PATCH] zram_drv: allow reclaim on bio_alloc > > > >On Mon, Sep 06, 2021 at 02:29:26PM +0900, Jaewon Kim wrote: > >> The read_from_bdev_async is not called on atomic context. So GFP_NOIO is > >> available rather than GFP_ATOMIC. If there were reclaimable pages with > >> GFP_NOIO, we can avoid allocation failure and page fault failure. > >> > >> Reported-by: Yong-Taek Lee <ytk.lee@samsung.com> > >> Signed-off-by: Jaewon Kim <jaewon31.kim@samsung.com> Looks reasonable to me. Feel free to add after dealing with Christoph's comment. Acked-by: Minchan Kim <minchan@kernel.org> Thank you. > >> --- > >> drivers/block/zram/zram_drv.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c > >> index fcaf2750f68f..53be528a39a2 100644 > >> --- a/drivers/block/zram/zram_drv.c > >> +++ b/drivers/block/zram/zram_drv.c > >> @@ -587,7 +587,7 @@ static int read_from_bdev_async(struct zram *zram, struct bio_vec *bvec, > >> { > >> struct bio *bio; > >> > >> - bio = bio_alloc(GFP_ATOMIC, 1); > >> + bio = bio_alloc(GFP_NOIO|__GFP_HIGHMEM, 1); > > > >Passing __GFP_HIGHMEM to bio_alloc does not make any sense whatsoever. > > > Correct, let me remove __GFP_HIGHMEM if I send v2 patch. > Thank you
> > >--------- Original Message --------- >Sender : Minchan Kim <minchan@kernel.org> >Date : 2021-09-08 02:00 (GMT+9) >Title : Re: (2) [PATCH] zram_drv: allow reclaim on bio_alloc > >Hi Jaewon, > >On Mon, Sep 06, 2021 at 06:14:48PM +0900, Jaewon Kim wrote: >> > >> > >> >--------- Original Message --------- >> >Sender : Christoph Hellwig <hch@infradead.org> >> >Date : 2021-09-06 17:39 (GMT+9) >> >Title : Re: [PATCH] zram_drv: allow reclaim on bio_alloc >> > >> >On Mon, Sep 06, 2021 at 02:29:26PM +0900, Jaewon Kim wrote: >> >> The read_from_bdev_async is not called on atomic context. So GFP_NOIO is >> >> available rather than GFP_ATOMIC. If there were reclaimable pages with >> >> GFP_NOIO, we can avoid allocation failure and page fault failure. >> >> >> >> Reported-by: Yong-Taek Lee <ytk.lee@samsung.com> >> >> Signed-off-by: Jaewon Kim <jaewon31.kim@samsung.com> > >Looks reasonable to me. >Feel free to add after dealing with Christoph's comment. > >Acked-by: Minchan Kim <minchan@kernel.org> > >Thank you. Thank you, I will send v2 patch soon. > >> >> --- >> >> drivers/block/zram/zram_drv.c | 2 +- >> >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> >> >> diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c >> >> index fcaf2750f68f..53be528a39a2 100644 >> >> --- a/drivers/block/zram/zram_drv.c >> >> +++ b/drivers/block/zram/zram_drv.c >> >> @@ -587,7 +587,7 @@ static int read_from_bdev_async(struct zram *zram, struct bio_vec *bvec, >> >> { >> >> struct bio *bio; >> >> >> >> - bio = bio_alloc(GFP_ATOMIC, 1); >> >> + bio = bio_alloc(GFP_NOIO|__GFP_HIGHMEM, 1); >> > >> >Passing __GFP_HIGHMEM to bio_alloc does not make any sense whatsoever. >> > >> Correct, let me remove __GFP_HIGHMEM if I send v2 patch. >> Thank you >
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index fcaf2750f68f..53be528a39a2 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -587,7 +587,7 @@ static int read_from_bdev_async(struct zram *zram, struct bio_vec *bvec, { struct bio *bio; - bio = bio_alloc(GFP_ATOMIC, 1); + bio = bio_alloc(GFP_NOIO|__GFP_HIGHMEM, 1); if (!bio) return -ENOMEM;
The read_from_bdev_async is not called on atomic context. So GFP_NOIO is available rather than GFP_ATOMIC. If there were reclaimable pages with GFP_NOIO, we can avoid allocation failure and page fault failure. Reported-by: Yong-Taek Lee <ytk.lee@samsung.com> Signed-off-by: Jaewon Kim <jaewon31.kim@samsung.com> --- drivers/block/zram/zram_drv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)