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Merge tag 'scsi-sg' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

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Pull SCSI scatter-gather list updates from James Bottomley:
 "This topic branch covers a fundamental change in how our sg lists are
  allocated to make mq more efficient by reducing the size of the
  preallocated sg list.

  This necessitates a large number of driver changes because the
  previous guarantee that if a driver specified SG_ALL as the size of
  its scatter list, it would get a non-chained list and didn't need to
  bother with scatterlist iterators is now broken and every driver
  *must* use scatterlist iterators.

  This was broken out as a separate topic because we need to convert all
  the drivers before pulling the trigger and unconverted drivers kept
  being found, necessitating a rebase"

* tag 'scsi-sg' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (21 commits)
  scsi: core: don't preallocate small SGL in case of NO_SG_CHAIN
  scsi: lib/sg_pool.c: clear 'first_chunk' in case of no preallocation
  scsi: core: avoid preallocating big SGL for data
  scsi: core: avoid preallocating big SGL for protection information
  scsi: lib/sg_pool.c: improve APIs for allocating sg pool
  scsi: esp: use sg helper to iterate over scatterlist
  scsi: NCR5380: use sg helper to iterate over scatterlist
  scsi: wd33c93: use sg helper to iterate over scatterlist
  scsi: ppa: use sg helper to iterate over scatterlist
  scsi: pcmcia: nsp_cs: use sg helper to iterate over scatterlist
  scsi: imm: use sg helper to iterate over scatterlist
  scsi: aha152x: use sg helper to iterate over scatterlist
  scsi: s390: zfcp_fc: use sg helper to iterate over scatterlist
  scsi: staging: unisys: visorhba: use sg helper to iterate over scatterlist
  scsi: usb: image: microtek: use sg helper to iterate over scatterlist
  scsi: pmcraid: use sg helper to iterate over scatterlist
  scsi: ipr: use sg helper to iterate over scatterlist
  scsi: mvumi: use sg helper to iterate over scatterlist
  scsi: lpfc: use sg helper to iterate over scatterlist
  scsi: advansys: use sg helper to iterate over scatterlist
  ...
This commit is contained in:
Linus Torvalds
2019-07-11 15:17:41 -07:00
parent ba6d10ab80 3e99b3b13a
commit 1f7563f743
26 changed files with 205 additions and 154 deletions
Download Patch File Download Diff File Expand all files Collapse all files

39
lib/sg_pool.c
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@@ -70,18 +70,27 @@ static struct scatterlist *sg_pool_alloc(unsigned int nents, gfp_t gfp_mask)
/**
* sg_free_table_chained - Free a previously mapped sg table
* @table: The sg table header to use
* @first_chunk: was first_chunk not NULL in sg_alloc_table_chained?
* @nents_first_chunk: size of the first_chunk SGL passed to
* sg_alloc_table_chained
*
* Description:
* Free an sg table previously allocated and setup with
* sg_alloc_table_chained().
*
* @nents_first_chunk has to be same with that same parameter passed
* to sg_alloc_table_chained().
*
**/
void sg_free_table_chained(struct sg_table *table, bool first_chunk)
void sg_free_table_chained(struct sg_table *table,
unsigned nents_first_chunk)
{
if (first_chunk && table->orig_nents <= SG_CHUNK_SIZE)
if (table->orig_nents <= nents_first_chunk)
return;
__sg_free_table(table, SG_CHUNK_SIZE, first_chunk, sg_pool_free);
if (nents_first_chunk == 1)
nents_first_chunk = 0;
__sg_free_table(table, SG_CHUNK_SIZE, nents_first_chunk, sg_pool_free);
}
EXPORT_SYMBOL_GPL(sg_free_table_chained);
@@ -90,31 +99,41 @@ EXPORT_SYMBOL_GPL(sg_free_table_chained);
* @table: The sg table header to use
* @nents: Number of entries in sg list
* @first_chunk: first SGL
* @nents_first_chunk: number of the SGL of @first_chunk
*
* Description:
* Allocate and chain SGLs in an sg table. If @nents@ is larger than
* SG_CHUNK_SIZE a chained sg table will be setup.
* @nents_first_chunk a chained sg table will be setup. @first_chunk is
* ignored if nents_first_chunk <= 1 because user expects the SGL points
* non-chain SGL.
*
**/
int sg_alloc_table_chained(struct sg_table *table, int nents,
struct scatterlist *first_chunk)
struct scatterlist *first_chunk, unsigned nents_first_chunk)
{
int ret;
BUG_ON(!nents);
if (first_chunk) {
if (nents <= SG_CHUNK_SIZE) {
if (first_chunk && nents_first_chunk) {
if (nents <= nents_first_chunk) {
table->nents = table->orig_nents = nents;
sg_init_table(table->sgl, nents);
return 0;
}
}
/* User supposes that the 1st SGL includes real entry */
if (nents_first_chunk <= 1) {
first_chunk = NULL;
nents_first_chunk = 0;
}
ret = __sg_alloc_table(table, nents, SG_CHUNK_SIZE,
first_chunk, GFP_ATOMIC, sg_pool_alloc);
first_chunk, nents_first_chunk,
GFP_ATOMIC, sg_pool_alloc);
if (unlikely(ret))
sg_free_table_chained(table, (bool)first_chunk);
sg_free_table_chained(table, nents_first_chunk);
return ret;
}
EXPORT_SYMBOL_GPL(sg_alloc_table_chained);