Barry Song fc8580edba mm: zsmalloc: return -ENOSPC rather than -EINVAL in zs_malloc while size is too large
This is the case the "compressed" data is larger than the original data,
it is better to return -ENOSPC which can help zswap record a poor compr
rather than an invalid request.  Then we get more friendly counting for
reject_compress_poor in debugfs.

 bool zswap_store(struct folio *folio)
 {
 	...
 	ret = zpool_malloc(zpool, dlen, gfp, &handle);
 	if (ret == -ENOSPC) {
 		zswap_reject_compress_poor++;
 		goto put_dstmem;
 	}
 	if (ret) {
 		zswap_reject_alloc_fail++;
 		goto put_dstmem;
 	}
 	...
 }

Also, zbud_alloc() and z3fold_alloc() are returning ENOSPC in the same
case, eg

 static int z3fold_alloc(struct z3fold_pool *pool, size_t size, gfp_t gfp,
 			unsigned long *handle)
 {
 	...
 	if (!size || (gfp & __GFP_HIGHMEM))
 		return -EINVAL;

 	if (size > PAGE_SIZE)
 		return -ENOSPC;
 	...
 }

Link: https://lkml.kernel.org/r/20231228061802.25280-1-v-songbaohua@oppo.com
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Reviewed-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-01-05 10:17:47 -08:00
2024-01-05 10:17:44 -08:00
2023-12-29 11:58:41 -08:00
2023-12-29 11:58:41 -08:00
2023-12-06 16:12:49 -08:00
2023-12-03 18:52:56 +09:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
S
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