From nobody Wed Dec 17 23:40:46 2025 Received: from mail-pf1-f181.google.com (mail-pf1-f181.google.com [209.85.210.181]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0439E153BD8 for ; Fri, 3 May 2024 09:19:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.181 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714727948; cv=none; b=VOhrtUCc5OWu5jMlujTbDBkIURa5klzanqNxQRHqbg80uoJ4dNRrC3+gnxFKzb05X+U8TbB65R9JpoTFZGaU4So8NtuSwa3Ye7IOqB6IsXPCDsaq5yajEb1ksmJWecLvf2wz7QUE4hJ14eMObEWjtje0g/jYDiMwPaAd2K+r2t8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714727948; c=relaxed/simple; bh=eO1aD3GYThTWX8reEG9IHaYxayASI5pIn3ZwxQRjfeY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Lbdp4fIIOnelIGHqVMf8cXsz5m5ZRgjfgIuErDOQeVpGDQz9QIiOeg69mTq1BXuhOjxH9wIagNw/wzO1/A8ifSVe5+NXZsFHOEjP/eAX36Ytes97kk9yspQtCOBWM4Ro+iNJCtAq5ECUB2vf7KWsNR8lqrubEq9EdBvlJxMZISM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org; spf=pass smtp.mailfrom=chromium.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b=IwMjDbm/; arc=none smtp.client-ip=209.85.210.181 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=chromium.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="IwMjDbm/" Received: by mail-pf1-f181.google.com with SMTP id d2e1a72fcca58-6f3e3d789cdso6496654b3a.1 for ; Fri, 03 May 2024 02:19:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1714727946; x=1715332746; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=6NlFlAwd7AfzOKAUbFYigEp0/QoNwrE2imVLFTnbDxc=; b=IwMjDbm/hX23VewTatSdy1IiTXYPJ2dKM9Q3QgfqVwsU/O3g8PvK8ZWI8KiVrQc721 laVvRAEBVyLUH2nsfE4143F62KA2ei35TwpB4PDhzMNn4Gl4BKf6Oj/0zMJN4azRFA2B knB+MnrNF97nHgYR1Kv8sEO2QZWlZL8wnsMtw= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1714727946; x=1715332746; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=6NlFlAwd7AfzOKAUbFYigEp0/QoNwrE2imVLFTnbDxc=; b=Ov/1h0Cy7NA9TdtpazpML2QXqq/ecqDxRrfLT7v7F24peKHnMtzb2tvgZJo6Aw7S+7 6vt8ZpraadFeQiclNDlv6aXX1muEhL7mY9Fbx6q2xEfKGvmtJjBHAimlPqkAJuSBp5xx mbaqFh/0mF6JxVND3qZ+zooIuEm9Q4lTI1kKnrxwGMAnhTuO46zYyjTzdc3O/BIQHXGD aMO73r29bQPRC5eC6EGdrjl6fEq1fwV7awSbZfki7H5Q1IA6qg6pjhlJco0NZW9PuZgM wUugCROme2iWEGKiV71SlhzUVewUA4Hg/pfLn4kJfk7/bRgyYm8NtGnOkEZ0gHb9FtQs mhcA== X-Gm-Message-State: AOJu0YyJRZ9IBJXoFCOjPAiQfnI7vb9LijJmTQkoXiM2Is7Bq5pqC7Zn vn9sFOoSUaSGpM3pSO4Nln0+bGSOLOZSvclRXkNelIJpzF9GdohOP13uQdbA9Q== X-Google-Smtp-Source: AGHT+IEss/I5uy/yYKBxcXXnNraFRQZ56Afeli3+NlY5upIAcfp/ukWooVoWmDX0bG0NTr8rjslCnA== X-Received: by 2002:a05:6300:8089:b0:1a7:3d2a:7383 with SMTP id ap9-20020a056300808900b001a73d2a7383mr2348105pzc.18.1714727946298; Fri, 03 May 2024 02:19:06 -0700 (PDT) Received: from tigerii.tok.corp.google.com ([2401:fa00:8f:203:dc60:24a3:e365:f27c]) by smtp.gmail.com with ESMTPSA id j6-20020aa78d06000000b006ecec1f4b08sm2621938pfe.118.2024.05.03.02.19.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 03 May 2024 02:19:06 -0700 (PDT) From: Sergey Senozhatsky To: Andrew Morton , Minchan Kim Cc: linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, Sergey Senozhatsky Subject: [PATCH 13/14] zram: add dictionary support to zstd backend Date: Fri, 3 May 2024 18:17:38 +0900 Message-ID: <20240503091823.3616962-14-senozhatsky@chromium.org> X-Mailer: git-send-email 2.45.0.rc1.225.g2a3ae87e7f-goog In-Reply-To: <20240503091823.3616962-1-senozhatsky@chromium.org> References: <20240503091823.3616962-1-senozhatsky@chromium.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" This adds support for pre-trained zstd dictionaries [1] Dictionary is loaded once (per-config) and then loaded to Cctx and Dctx by reference, so we don't allocate extra memory. The patch is a little non-trivial, as it seems that noone ever attempted to use dictionaries in the linux kernel port of zstd. It also uses GFP_KERNEL gfp in Cctx customAlloc(). We probably would want to do something about it. Either make sure that we always (somehow) fully setup all Cctx contexts from non-atomic context before we attempt to use them, come up with some sort of custom allocator or stop calling zcomp_compress() from atomic context. [1] https://github.com/facebook/zstd/blob/dev/programs/zstd.1.md#dictionary= -builder Signed-off-by: Sergey Senozhatsky --- drivers/block/zram/backend_zstd.c | 119 ++++++++++++++++++++++++------ 1 file changed, 96 insertions(+), 23 deletions(-) diff --git a/drivers/block/zram/backend_zstd.c b/drivers/block/zram/backend= _zstd.c index b2fb94902bef..6220c154e54e 100644 --- a/drivers/block/zram/backend_zstd.c +++ b/drivers/block/zram/backend_zstd.c @@ -12,23 +12,47 @@ struct zstd_ctx { zstd_dctx *dctx; void *cctx_mem; void *dctx_mem; + ZSTD_customMem cctx_cmem; + ZSTD_customMem dctx_cmem; + ZSTD_CDict *cdict; + ZSTD_DDict *ddict; s32 level; }; =20 +/* + * Cctx allocator.customAlloc() is called from zcom_compress(), which is + * called under local-lock (per-CPU compression stream), so we need to + * use GFP_ATOMIC here. + */ +static void *zstd_cctx_alloc(void *opaque, size_t size) +{ + return kvzalloc(size, GFP_ATOMIC); +} + +static void *zstd_dctx_alloc(void *opaque, size_t size) +{ + return kvzalloc(size, GFP_KERNEL); +} + +static void zstd_ctx_free(void *opaque, void *address) +{ + kvfree(address); +} + static void zstd_destroy(void *ctx) { struct zstd_ctx *zctx =3D ctx; =20 vfree(zctx->cctx_mem); vfree(zctx->dctx_mem); + ZSTD_freeCDict(zctx->cdict); + ZSTD_freeDDict(zctx->ddict); kfree(zctx); } =20 static void *zstd_create(struct zcomp_config *config) { - zstd_parameters params; struct zstd_ctx *ctx; - size_t sz; =20 ctx =3D kzalloc(sizeof(*ctx), GFP_KERNEL); if (!ctx) @@ -39,24 +63,64 @@ static void *zstd_create(struct zcomp_config *config) else ctx->level =3D ZSTD_defaultCLevel(); =20 - params =3D zstd_get_params(ctx->level, PAGE_SIZE); - sz =3D zstd_cctx_workspace_bound(¶ms.cParams); - ctx->cctx_mem =3D vzalloc(sz); - if (!ctx->cctx_mem) - goto error; - - ctx->cctx =3D zstd_init_cctx(ctx->cctx_mem, sz); - if (!ctx->cctx) - goto error; - - sz =3D zstd_dctx_workspace_bound(); - ctx->dctx_mem =3D vzalloc(sz); - if (!ctx->dctx_mem) - goto error; - - ctx->dctx =3D zstd_init_dctx(ctx->dctx_mem, sz); - if (!ctx->dctx) - goto error; + ctx->cctx_cmem.customAlloc =3D zstd_cctx_alloc; + ctx->cctx_cmem.customFree =3D zstd_ctx_free; + ctx->dctx_cmem.customAlloc =3D zstd_dctx_alloc; + ctx->dctx_cmem.customFree =3D zstd_ctx_free; + + if (config->dict_sz =3D=3D 0) { + zstd_parameters params; + size_t sz; + + params =3D zstd_get_params(ctx->level, PAGE_SIZE); + sz =3D zstd_cctx_workspace_bound(¶ms.cParams); + ctx->cctx_mem =3D vzalloc(sz); + if (!ctx->cctx_mem) + goto error; + + ctx->cctx =3D zstd_init_cctx(ctx->cctx_mem, sz); + if (!ctx->cctx) + goto error; + + sz =3D zstd_dctx_workspace_bound(); + ctx->dctx_mem =3D vzalloc(sz); + if (!ctx->dctx_mem) + goto error; + + ctx->dctx =3D zstd_init_dctx(ctx->dctx_mem, sz); + if (!ctx->dctx) + goto error; + } else { + ZSTD_compressionParameters params; + + ctx->cctx =3D ZSTD_createCCtx_advanced(ctx->cctx_cmem); + if (!ctx->cctx) + goto error; + + ctx->dctx =3D ZSTD_createDCtx_advanced(ctx->dctx_cmem); + if (!ctx->dctx) + goto error; + + params =3D ZSTD_getCParams(ctx->level, PAGE_SIZE, + config->dict_sz); + + ctx->cdict =3D ZSTD_createCDict_advanced(config->dict, + config->dict_sz, + ZSTD_dlm_byRef, + ZSTD_dct_auto, + params, + ctx->cctx_cmem); + if (!ctx->cdict) + goto error; + + ctx->ddict =3D ZSTD_createDDict_advanced(config->dict, + config->dict_sz, + ZSTD_dlm_byRef, + ZSTD_dct_auto, + ctx->dctx_cmem); + if (!ctx->ddict) + goto error; + } =20 return ctx; =20 @@ -72,8 +136,12 @@ static int zstd_compress(void *ctx, const unsigned char= *src, const zstd_parameters params =3D zstd_get_params(zctx->level, PAGE_SIZE); size_t ret; =20 - ret =3D zstd_compress_cctx(zctx->cctx, dst, *dst_len, - src, PAGE_SIZE, ¶ms); + if (!zctx->cdict) + ret =3D zstd_compress_cctx(zctx->cctx, dst, *dst_len, + src, PAGE_SIZE, ¶ms); + else + ret =3D ZSTD_compress_usingCDict(zctx->cctx, dst, *dst_len, + src, PAGE_SIZE, zctx->cdict); if (zstd_is_error(ret)) return -EINVAL; *dst_len =3D ret; @@ -86,7 +154,12 @@ static int zstd_decompress(void *ctx, const unsigned ch= ar *src, size_t src_len, struct zstd_ctx *zctx =3D ctx; size_t ret; =20 - ret =3D zstd_decompress_dctx(zctx->dctx, dst, PAGE_SIZE, src, src_len); + if (!zctx->ddict) + ret =3D zstd_decompress_dctx(zctx->dctx, dst, PAGE_SIZE, + src, src_len); + else + ret =3D ZSTD_decompress_usingDDict(zctx->dctx, dst, PAGE_SIZE, + src, src_len, zctx->ddict); if (zstd_is_error(ret)) return -EINVAL; return 0; --=20 2.45.0.rc1.225.g2a3ae87e7f-goog