On Wed, Jun 05, 2019 at 01:57:03PM +0200, David Sterba wrote: > On Tue, Jun 04, 2019 at 03:43:26PM -0700, Andrew Morton wrote: > > On Mon, 3 Jun 2019 14:32:03 +0530 Maninder Singh <maninder1.s@xxxxxxxxxxx> wrote: > > > > > currently params structure is passed in all functions, which increases > > > stack usage in all the function and lead to stack overflow on target like > > > ARM with kernel stack size of 8 KB so better to pass pointer. > > > > > > Checked for ARM: > > > > > > Original Patched > > > Call FLow Size: 1264 1040 > > > .... > > > (HUF_sort) -> 296 > > > (HUF_buildCTable_wksp) -> 144 > > > (HUF_compress4X_repeat) -> 88 > > > (ZSTD_compressBlock_internal) -> 200 > > > (ZSTD_compressContinue_internal)-> 136 -> 88 > > > (ZSTD_compressCCtx) -> 192 -> 64 > > > (zstd_compress) -> 144 -> 96 > > > (crypto_compress) -> 32 > > > (zcomp_compress) -> 32 > > > .... > > > > > > Signed-off-by: Maninder Singh <maninder1.s@xxxxxxxxxxx> > > > Signed-off-by: Vaneet Narang <v.narang@xxxxxxxxxxx> > > > > > > > You missed btrfs. This needs review, please - particularly the > > kernel-wide static ZSTD_parameters in zstd_get_btrfs_parameters(). > > > > > The base patch is here: > > > > http://lkml.kernel.org/r/1559552526-4317-2-git-send-email-maninder1.s@xxxxxxxxxxx > > > > --- a/fs/btrfs/zstd.c~zstd-pass-pointer-rathen-than-structure-to-functions-fix > > +++ a/fs/btrfs/zstd.c > > @@ -27,15 +27,17 @@ > > /* 307s to avoid pathologically clashing with transaction commit */ > > #define ZSTD_BTRFS_RECLAIM_JIFFIES (307 * HZ) > > > > -static ZSTD_parameters zstd_get_btrfs_parameters(unsigned int level, > > +static ZSTD_parameters *zstd_get_btrfs_parameters(unsigned int level, > > size_t src_len) > > { > > - ZSTD_parameters params = ZSTD_getParams(level, src_len, 0); > > + static ZSTD_parameters params; > > > + > > + params = ZSTD_getParams(level, src_len, 0); > > No thats' broken, the params can't be static as it depends on level and > src_len. What happens if there are several requests in parallel with > eg. different levels? > > Would be really great if the mailinglist is CCed when the code is > changed in a non-trivial way. So this does not compile fs/btrfs/zstd.o which Andrew probably found too, otherwise btrfs is the only in-tree user of the function outside of lib/ and crypto/. I think that Nick Terrell should have been CCed too, as he ported zstd to linux.
