2018-03-12 13:48 GMT+01:00 Salvatore Mesoraca <s.mesoraca16@xxxxxxxxx>: > Avoid 3 VLAs[1] by using a single dinamically allocated array > and some helper variables: we don't need 3 arrays. > > [1] https://lkml.org/lkml/2018/3/7/621 > > Signed-off-by: Salvatore Mesoraca <s.mesoraca16@xxxxxxxxx> > --- > drivers/scsi/eata.c | 40 ++++++++++++++++++++++++++-------------- > 1 file changed, 26 insertions(+), 14 deletions(-) > > diff --git a/drivers/scsi/eata.c b/drivers/scsi/eata.c > index 6501c33..8ba44b7 100644 > --- a/drivers/scsi/eata.c > +++ b/drivers/scsi/eata.c > @@ -2091,12 +2091,14 @@ static void sort(unsigned long sk[], unsigned int da[], unsigned int n, > static int reorder(struct hostdata *ha, unsigned long cursec, > unsigned int ihdlr, unsigned int il[], unsigned int n_ready) > { > + int overlap; > struct scsi_cmnd *SCpnt; > struct mscp *cpp; > unsigned int k, n; > unsigned int rev = 0, s = 1, r = 1; > - unsigned int input_only = 1, overlap = 0; > - unsigned long sl[n_ready], pl[n_ready], ll[n_ready]; > + unsigned int input_only = 1; > + unsigned long *sl; > + unsigned long sl_zero, sl_cur, sl_prev, ll_cur, ll_prev; > unsigned long maxsec = 0, minsec = ULONG_MAX, seek = 0, iseek = 0; > unsigned long ioseek = 0; > > @@ -2115,6 +2117,12 @@ static int reorder(struct hostdata *ha, unsigned long cursec, > if (n_ready <= 1) > return 0; > > + overlap = -ENOMEM; > + sl = kcalloc(n_ready, sizeof(*sl), GFP_ATOMIC); I should have used kmalloc_array :/ Sending v3 > + if (!sl) > + goto out; > + overlap = 0; > + > for (n = 0; n < n_ready; n++) { > k = il[n]; > cpp = &ha->cp[k]; > @@ -2164,31 +2172,33 @@ static int reorder(struct hostdata *ha, unsigned long cursec, > if (!((rev && r) || (!rev && s))) > sort(sl, il, n_ready, rev); > > + sl_zero = sl[0]; > + > if (!input_only) > for (n = 0; n < n_ready; n++) { > k = il[n]; > cpp = &ha->cp[k]; > SCpnt = cpp->SCpnt; > - ll[n] = blk_rq_sectors(SCpnt->request); > - pl[n] = SCpnt->serial_number; > + ll_cur = blk_rq_sectors(SCpnt->request); > + sl_cur = sl[n]; > + sl[n] = SCpnt->serial_number; > > - if (!n) > - continue; > - > - if ((sl[n] == sl[n - 1]) > - || (!rev && ((sl[n - 1] + ll[n - 1]) > sl[n])) > - || (rev && ((sl[n] + ll[n]) > sl[n - 1]))) > + if (n && ((sl_cur == sl_prev) > + || (!rev && ((sl_prev + ll_prev) > sl_cur)) > + || (rev && ((sl_cur + ll_cur) > sl_prev)))) > overlap = 1; > + ll_prev = ll_cur; > + sl_prev = sl_cur; > } > > if (overlap) > - sort(pl, il, n_ready, 0); > + sort(sl, il, n_ready, 0); > > if (link_statistics) { > - if (cursec > sl[0]) > - iseek = cursec - sl[0]; > + if (cursec > sl_zero) > + iseek = cursec - sl_zero; > else > - iseek = sl[0] - cursec; > + iseek = sl_zero - cursec; > batchcount++; > readycount += n_ready; > seeknosort += seek / 1024; > @@ -2225,6 +2235,8 @@ static int reorder(struct hostdata *ha, unsigned long cursec, > YESNO(overlap), cpp->din); > } > #endif > + kfree(sl); > +out: > return overlap; > } > > -- > 1.9.1 >
