On (08/13/14 10:31), Jerome Marchand wrote: > Date: Wed, 13 Aug 2014 10:31:45 +0200 > From: Jerome Marchand <[email protected]> > To: Chao Yu <[email protected]>, [email protected] > CC: [email protected], [email protected], 'Sergey Senozhatsky' > <[email protected]>, 'Andrew Morton' > <[email protected]> > Subject: Re: [PATCH v2] zram: fix incorrectly stat with failed_reads > User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 > Thunderbird/24.6.0 > > On 08/13/2014 04:01 AM, Chao Yu wrote: > > Since we allocate a temporary buffer in zram_bvec_read to handle partial > > page > > operations in this commit 924bd88d703e53d30f393fac6117f8f1bc79aab6 (Staging: > > zram: allow partial page operations), our ->failed_reads value may be > > incorrect > > as we do not increase its value when failed to allocate the temporary > > buffer. > > > > Let's fix this issue and correct the annotation of failed_reads. > > > > v2: clean codes of failed_{reads,writes} stat pointed out by Minchan Kim, > > and > > this cleanup also fix incorrectly stat when fail in zram_decompress_page. > > > > Signed-off-by: Chao Yu <[email protected]> > > Acked-by: Jerome Marchand <[email protected]>
Acked-by: Sergey Senozhatsky <[email protected]> -ss > > --- > > drivers/block/zram/zram_drv.c | 10 +++++++--- > > drivers/block/zram/zram_drv.h | 2 +- > > 2 files changed, 8 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c > > index dfa4024..d00831c 100644 > > --- a/drivers/block/zram/zram_drv.c > > +++ b/drivers/block/zram/zram_drv.c > > @@ -378,7 +378,6 @@ static int zram_decompress_page(struct zram *zram, char > > *mem, u32 index) > > /* Should NEVER happen. Return bio error if it does. */ > > if (unlikely(ret)) { > > pr_err("Decompression failed! err=%d, page=%u\n", ret, index); > > - atomic64_inc(&zram->stats.failed_reads); > > return ret; > > } > > > > @@ -547,8 +546,6 @@ out: > > zcomp_strm_release(zram->comp, zstrm); > > if (is_partial_io(bvec)) > > kfree(uncmem); > > - if (ret) > > - atomic64_inc(&zram->stats.failed_writes); > > return ret; > > } > > > > @@ -566,6 +563,13 @@ static int zram_bvec_rw(struct zram *zram, struct > > bio_vec *bvec, u32 index, > > ret = zram_bvec_write(zram, bvec, index, offset); > > } > > > > + if (unlikely(ret)) { > > + if (rw == READ) > > + atomic64_inc(&zram->stats.failed_reads); > > + else > > + atomic64_inc(&zram->stats.failed_writes); > > + } > > + > > return ret; > > } > > > > diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h > > index 5b0afde..e0f725c 100644 > > --- a/drivers/block/zram/zram_drv.h > > +++ b/drivers/block/zram/zram_drv.h > > @@ -84,7 +84,7 @@ struct zram_stats { > > atomic64_t compr_data_size; /* compressed size of pages stored */ > > atomic64_t num_reads; /* failed + successful */ > > atomic64_t num_writes; /* --do-- */ > > - atomic64_t failed_reads; /* should NEVER! happen */ > > + atomic64_t failed_reads; /* can happen when memory is too low */ > > atomic64_t failed_writes; /* can happen when memory is too low */ > > atomic64_t invalid_io; /* non-page-aligned I/O requests */ > > atomic64_t notify_free; /* no. of swap slot free notifications */ > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
