Re: [RFC PATCH v1 11/13] mm: swap: Add IAA batch compression API swap_crypto_acomp_compress_batch().

[kernel test robot <lkp@intel.com>]

Hi Kanchana,

[This is a private test report for your RFC patch.]
kernel test robot noticed the following build warnings:

[auto build test WARNING on 817952b8be34aad40e07f6832fb9d1fc08961550]

url:    https://github.com/intel-lab-lkp/linux/commits/Kanchana-P-Sridhar/crypto-acomp-Add-a-poll-operation-to-acomp_alg-and-acomp_req/20241018-144331
base:   817952b8be34aad40e07f6832fb9d1fc08961550
patch link:    https://lore.kernel.org/r/20241018064101.336232-12-kanchana.p.sridhar%40intel.com
patch subject: [RFC PATCH v1 11/13] mm: swap: Add IAA batch compression API swap_crypto_acomp_compress_batch().
config: x86_64-kexec (https://download.01.org/0day-ci/archive/20241019/202410191141.BwtDVXQ6-lkp@intel.com/config)
compiler: clang version 18.1.8 (https://github.com/llvm/llvm-project 3b5b5c1ec4a3095ab096dd780e84d7ab81f3d7ff)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241019/202410191141.BwtDVXQ6-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410191141.BwtDVXQ6-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> mm/swap_state.c:750: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
    * This API provides IAA compress batching functionality for use by swap


vim +750 mm/swap_state.c

   748	
   749	/**
 > 750	 * This API provides IAA compress batching functionality for use by swap
   751	 * modules.
   752	 * The acomp_ctx mutex should be locked/unlocked before/after calling this
   753	 * procedure.
   754	 *
   755	 * @pages: Pages to be compressed.
   756	 * @dsts: Pre-allocated destination buffers to store results of IAA compression.
   757	 * @dlens: Will contain the compressed lengths.
   758	 * @errors: Will contain a 0 if the page was successfully compressed, or a
   759	 *          non-0 error value to be processed by the calling function.
   760	 * @nr_pages: The number of pages, up to SWAP_CRYPTO_SUB_BATCH_SIZE,
   761	 *            to be compressed.
   762	 * @acomp_ctx: The acomp context for iaa_crypto/other compressor.
   763	 */
   764	void swap_crypto_acomp_compress_batch(
   765		struct page *pages[],
   766		u8 *dsts[],
   767		unsigned int dlens[],
   768		int errors[],
   769		int nr_pages,
   770		struct crypto_acomp_ctx *acomp_ctx)
   771	{
   772		struct scatterlist inputs[SWAP_CRYPTO_SUB_BATCH_SIZE];
   773		struct scatterlist outputs[SWAP_CRYPTO_SUB_BATCH_SIZE];
   774		bool compressions_done = false;
   775		int i, j;
   776	
   777		BUG_ON(nr_pages > SWAP_CRYPTO_SUB_BATCH_SIZE);
   778	
   779		/*
   780		 * Prepare and submit acomp_reqs to IAA.
   781		 * IAA will process these compress jobs in parallel in async mode.
   782		 * If the compressor does not support a poll() method, or if IAA is
   783		 * used in sync mode, the jobs will be processed sequentially using
   784		 * acomp_ctx->req[0] and acomp_ctx->wait.
   785		 */
   786		for (i = 0; i < nr_pages; ++i) {
   787			j = acomp_ctx->acomp->poll ? i : 0;
   788			sg_init_table(&inputs[i], 1);
   789			sg_set_page(&inputs[i], pages[i], PAGE_SIZE, 0);
   790	
   791			/*
   792			 * Each acomp_ctx->buffer[] is of size (PAGE_SIZE * 2).
   793			 * Reflect same in sg_list.
   794			 */
   795			sg_init_one(&outputs[i], dsts[i], PAGE_SIZE * 2);
   796			acomp_request_set_params(acomp_ctx->req[j], &inputs[i],
   797						 &outputs[i], PAGE_SIZE, dlens[i]);
   798	
   799			/*
   800			 * If the crypto_acomp provides an asynchronous poll()
   801			 * interface, submit the request to the driver now, and poll for
   802			 * a completion status later, after all descriptors have been
   803			 * submitted. If the crypto_acomp does not provide a poll()
   804			 * interface, submit the request and wait for it to complete,
   805			 * i.e., synchronously, before moving on to the next request.
   806			 */
   807			if (acomp_ctx->acomp->poll) {
   808				errors[i] = crypto_acomp_compress(acomp_ctx->req[j]);
   809	
   810				if (errors[i] != -EINPROGRESS)
   811					errors[i] = -EINVAL;
   812				else
   813					errors[i] = -EAGAIN;
   814			} else {
   815				errors[i] = crypto_wait_req(
   816						      crypto_acomp_compress(acomp_ctx->req[j]),
   817						      &acomp_ctx->wait);
   818				if (!errors[i])
   819					dlens[i] = acomp_ctx->req[j]->dlen;
   820			}
   821		}
   822	
   823		/*
   824		 * If not doing async compressions, the batch has been processed at
   825		 * this point and we can return.
   826		 */
   827		if (!acomp_ctx->acomp->poll)
   828			return;
   829	
   830		/*
   831		 * Poll for and process IAA compress job completions
   832		 * in out-of-order manner.
   833		 */
   834		while (!compressions_done) {
   835			compressions_done = true;
   836	
   837			for (i = 0; i < nr_pages; ++i) {
   838				/*
   839				 * Skip, if the compression has already completed
   840				 * successfully or with an error.
   841				 */
   842				if (errors[i] != -EAGAIN)
   843					continue;
   844	
   845				errors[i] = crypto_acomp_poll(acomp_ctx->req[i]);
   846	
   847				if (errors[i]) {
   848					if (errors[i] == -EAGAIN)
   849						compressions_done = false;
   850				} else {
   851					dlens[i] = acomp_ctx->req[i]->dlen;
   852				}
   853			}
   854		}
   855	}
   856	EXPORT_SYMBOL_GPL(swap_crypto_acomp_compress_batch);
   857	

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