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Date: Mon, 31 Jan 2022 17:07:10 +0100 From: Ulf Hansson <ulf.hansson@...aro.org> To: Yury Norov <yury.norov@...il.com> Cc: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>, Rasmus Villemoes <linux@...musvillemoes.dk>, Andrew Morton <akpm@...ux-foundation.org>, Michał Mirosław <mirq-linux@...e.qmqm.pl>, Greg Kroah-Hartman <gregkh@...uxfoundation.org>, Peter Zijlstra <peterz@...radead.org>, David Laight <david.laight@...lab.com>, Joe Perches <joe@...ches.com>, Dennis Zhou <dennis@...nel.org>, Emil Renner Berthing <kernel@...il.dk>, Nicholas Piggin <npiggin@...il.com>, Matti Vaittinen <matti.vaittinen@...rohmeurope.com>, Alexey Klimov <aklimov@...hat.com>, linux-kernel@...r.kernel.org, Maxim Levitsky <maximlevitsky@...il.com>, Alex Dubov <oakad@...oo.com>, Jens Axboe <axboe@...nel.dk>, Luis Chamberlain <mcgrof@...nel.org>, Colin Ian King <colin.king@...el.com>, Arnd Bergmann <arnd@...db.de>, Shubhankar Kuranagatti <shubhankarvk@...il.com>, linux-mmc@...r.kernel.org Subject: Re: [PATCH 30/54] drivers/memstick: replace bitmap_weight with bitmap_weight_eq where appropriate On Sun, 23 Jan 2022 at 19:41, Yury Norov <yury.norov@...il.com> wrote: > > msb_validate_used_block_bitmap() calls bitmap_weight() to compare the > weight of bitmap with a given number. We can do it more efficiently with > bitmap_weight_eq because conditional bitmap_weight may stop traversing the > bitmap earlier, as soon as condition is met. > > Signed-off-by: Yury Norov <yury.norov@...il.com> Acked-by: Ulf Hansson <ulf.hansson@...aro.org> Kind regards Uffe > --- > drivers/memstick/core/ms_block.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/memstick/core/ms_block.c b/drivers/memstick/core/ms_block.c > index 0cda6c6baefc..5cdd987e78f7 100644 > --- a/drivers/memstick/core/ms_block.c > +++ b/drivers/memstick/core/ms_block.c > @@ -155,8 +155,8 @@ static int msb_validate_used_block_bitmap(struct msb_data *msb) > for (i = 0; i < msb->zone_count; i++) > total_free_blocks += msb->free_block_count[i]; > > - if (msb->block_count - bitmap_weight(msb->used_blocks_bitmap, > - msb->block_count) == total_free_blocks) > + if (bitmap_weight_eq(msb->used_blocks_bitmap, msb->block_count, > + msb->block_count - total_free_blocks)) > return 0; > > pr_err("BUG: free block counts don't match the bitmap"); > -- > 2.30.2 >
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