| Message ID | 7b0a1e010fc4bf6e22dce274aa9400d942459e14.1487354456.git.dsterba@suse.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
At 02/18/2017 02:05 AM, David Sterba wrote: > Move the buffer limit definitions out of compress_file_range. > Nice one. No longer need to dig the codes to know the 128K limit now. Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Thanks, Qu > Signed-off-by: David Sterba <dsterba@suse.com> > --- > fs/btrfs/compression.h | 15 +++++++++++++++ > fs/btrfs/inode.c | 10 ---------- > 2 files changed, 15 insertions(+), 10 deletions(-) > > diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h > index e453f42b3bbf..c9d7e552cfa8 100644 > --- a/fs/btrfs/compression.h > +++ b/fs/btrfs/compression.h > @@ -19,6 +19,21 @@ > #ifndef __BTRFS_COMPRESSION_ > #define __BTRFS_COMPRESSION_ > > +/* > + * We want to make sure that amount of RAM required to uncompress an extent is > + * reasonable, so we limit the total size in ram of a compressed extent to > + * 128k. This is a crucial number because it also controls how easily we can > + * spread reads across cpus for decompression. > + * > + * We also want to make sure the amount of IO required to do a random read is > + * reasonably small, so we limit the size of a compressed extent to 128k. > + */ > + > +/* Maximum length of compressed data stored on disk */ > +#define BTRFS_MAX_COMPRESSED (SZ_128K) > +/* Maximum size of data before compression */ > +#define BTRFS_MAX_UNCOMPRESSED (SZ_128K) > + > void btrfs_init_compress(void); > void btrfs_exit_compress(void); > > diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c > index 801d1b3fd9d7..bc547608ff1a 100644 > --- a/fs/btrfs/inode.c > +++ b/fs/btrfs/inode.c > @@ -470,16 +470,6 @@ static noinline void compress_file_range(struct inode *inode, > (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size)) > goto cleanup_and_bail_uncompressed; > > - /* we want to make sure that amount of ram required to uncompress > - * an extent is reasonable, so we limit the total size in ram > - * of a compressed extent to 128k. This is a crucial number > - * because it also controls how easily we can spread reads across > - * cpus for decompression. > - * > - * We also want to make sure the amount of IO required to do > - * a random read is reasonably small, so we limit the size of > - * a compressed extent to 128k. > - */ > total_compressed = min(total_compressed, max_uncompressed); > num_bytes = ALIGN(end - start + 1, blocksize); > num_bytes = max(blocksize, num_bytes); > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h index e453f42b3bbf..c9d7e552cfa8 100644 --- a/fs/btrfs/compression.h +++ b/fs/btrfs/compression.h @@ -19,6 +19,21 @@ #ifndef __BTRFS_COMPRESSION_ #define __BTRFS_COMPRESSION_ +/* + * We want to make sure that amount of RAM required to uncompress an extent is + * reasonable, so we limit the total size in ram of a compressed extent to + * 128k. This is a crucial number because it also controls how easily we can + * spread reads across cpus for decompression. + * + * We also want to make sure the amount of IO required to do a random read is + * reasonably small, so we limit the size of a compressed extent to 128k. + */ + +/* Maximum length of compressed data stored on disk */ +#define BTRFS_MAX_COMPRESSED (SZ_128K) +/* Maximum size of data before compression */ +#define BTRFS_MAX_UNCOMPRESSED (SZ_128K) + void btrfs_init_compress(void); void btrfs_exit_compress(void); diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 801d1b3fd9d7..bc547608ff1a 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -470,16 +470,6 @@ static noinline void compress_file_range(struct inode *inode, (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size)) goto cleanup_and_bail_uncompressed; - /* we want to make sure that amount of ram required to uncompress - * an extent is reasonable, so we limit the total size in ram - * of a compressed extent to 128k. This is a crucial number - * because it also controls how easily we can spread reads across - * cpus for decompression. - * - * We also want to make sure the amount of IO required to do - * a random read is reasonably small, so we limit the size of - * a compressed extent to 128k. - */ total_compressed = min(total_compressed, max_uncompressed); num_bytes = ALIGN(end - start + 1, blocksize); num_bytes = max(blocksize, num_bytes);
Move the buffer limit definitions out of compress_file_range. Signed-off-by: David Sterba <dsterba@suse.com> --- fs/btrfs/compression.h | 15 +++++++++++++++ fs/btrfs/inode.c | 10 ---------- 2 files changed, 15 insertions(+), 10 deletions(-)